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Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control.

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Presentation on theme: "Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control."— Presentation transcript:

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2 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D Power and Control Devices

3 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 The intent of this presentation is to present enough information to provide the reader with a fundamental knowledge of electrical power and control devices used within Michelin and to better understand basic system and equipment operations.

4 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D Power and Control Devices Module 1 – Relays and Contactors Module 2 – Overload Relays Module 3 – IEC and NEMA Components Module 4 – Control Relay Applications Module 5 – Timers and Contact Blocks Module 6 – Solenoids Module 7 – Troubleshooting Power and Control Devices Module 1 – Relays and Contactors Module 2 – Overload Relays Module 3 – IEC and NEMA Components Module 4 – Control Relay Applications Module 5 – Timers and Contact Blocks Module 6 – Solenoids Module 7 – Troubleshooting Power and Control Devices

5 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Module 1 Relays and Contactors Module 1: Relays and Contactors

6 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Theory of Operation Module 1: Relays and Contactors

7 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Theory of Operation Purpose Both relays and contactors provide a means of automatic operation of a machine from a remote location. A contactor belongs to both the control circuit and the power circuit. The contactor coil and auxiliary contacts such as those required to seal-in or provide electrical interlock are found in the control circuit. The remaining main contacts are used to switch loads in the power circuit. A relay is always used in the control circuit. It is used to remember machine events such as the momentary closure of a limit switch contact. It is also used to overcome contact constraints, such as, incorrect type or not enough normally open or normally closed contacts available on a particular device. Module 1: Relays and Contactors

8 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Theory of Operation Operation and Construction Case or Housing Contains all the parts and provides the insulation necessary to isolate individual contacts. Contacts Main contacts, usually three and each of them having Fixed contact Movable contact Sometimes an arc blow-out device Auxiliary contacts, usually on the device or added and having Fixed contact; Movable contact Different types: Normally open contact; Normally closed contact Note: Auxiliary contacts should open and close at the same time as the main contacts and can be used to control various other circuits. Module 1: Relays and Contactors

9 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Theory of Operation Return Spring This spring insures that the moveable core rapidly moves away for the stationary core when the coil is de-energized. This rapid opening insures that the contacts, both main and auxiliary open as quickly as possible. Electromagnet The main feature of a contactor that distinguishes it from a manual starter is the use of an electromagnet. The electromagnet is ultimately responsible for switching the state of the contacts. The electromagnet consists of the following: Module 1: Relays and Contactors

10 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Theory of Operation Coil The coil produces magnetic flux as the result of current flow. The impedance of the coil limits the current in an AC circuit. The coil's impedance is mainly inductive reactance since the coil usually has a very low internal resistance. Note: Only the DC resistance of the coil limits the current in a DC circuit. Stationary Core The stationary core concentrates magnetic flux. In doing so, this core's surface, which mates with the moveable core, is polarized and attracts the moveable core. This core is constructed of laminated steel to reduce Eddy currents. Module 1: Relays and Contactors

11 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Theory of Operation Movable Core The moveable core also concentrates magnetic flux. The moveable core concentrates magnetic flux radiating from the mating surfaces of the stationary core. As a result, the mating surfaces of the moveable core are attracted to the stationary core resulting in the movement of the moveable core against the stationary core. The moveable core is attached through a plastic or insulated assembly to the contacts. As the moveable core is pulled against the stationary core, the contacts change state. Since the moveable core is made to move, it is often referred to as the armature. This core is also constructed of laminated steel to reduce Eddy currents. Module 1: Relays and Contactors

12 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Theory of Operation There are two inherent problems when an AC voltage is applied to a relay or contactor coil. The change in magnetic flux with respect to time induces a voltage in the core resulting in undesirable induced currents called eddy currents. The core is constructed of laminated steel to reduce these eddy currents. Laminations serve to increase the electrical resistance of the core. If the resistance of the core is doubled, the current is halved. Then from Watt's Law, we see that a reduction in current results in a significant reduction in power since P = I 2 R. Eddy currents are undesirable because they result in power dissipated by the core in the form of heat. Module 1: Relays and Contactors

13 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Theory of Operation The magnetic flux produced by the coil also goes to zero twice per cycle due to the alternations of the sine wave. Since there is no magnetic attraction, the two cores try to pull apart during these two instants in time. Since this pulling apart would cause the relay or contactor to chatter, something must retain the magnetic attraction during these times. Shading rings are embedded in the surface of the stationary core. These rings retain magnetic flux as the coil current passes through zero. The amount of magnetic flux produced by the coil is proportional to the current through the coil. As coil current passes through zero, it is making its greatest change with respect to time. Since the flux and current are in phase, flux is also making its greatest change with respect to time. This rapid change in flux causes an induced voltage and thus current to flow in the shading ring. As the result of current flow in the shading ring, a small magnetic field is created. The strength of this magnetic field is sufficient to retain the attraction of the two cores during the instant the main magnetic field passes through zero. Module 1: Relays and Contactors

14 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Theory of Operation The contactor and relay functions mechanically exactly the same. The cross-section drawing below shows how the moveable contacts are mechanically connected to the moveable part of the magnetic circuit. When the moveable part of the magnetic circuit is pulled against the return spring, the moveable part of the contacts either closes or opens relative to the stationary set of corresponding contacts. The illustration shown is a mechanical representation of the contactor. The moveable and stationary contacts must be electrically insulated and isolated from each other, the magnetic circuit and the coil. There are many different variations of contact configurations. Module 1: Relays and Contactors

15 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Theory of Operation There are more than one symbols for a contactor or a relay. These devices are a combination of many symbols, such as contacts and coils. Below is an electrical representation for a contactor and a relay. Both contain a coil that has terminal numbers A1 and A2. The contactor has three main contacts numbered L1 –T1, L2 – T2, L3 – T3, which are designed to carry heavy loads to motors, heaters, etc. The darker lines show these main contacts. The contactors auxiliary contacts are shown with smaller lines and numbered 13 – 14. The relay has all smaller auxiliary type contacts with different numbers. The numbers will be different for different configurations of contacts. The one shown is two normally open and two normally closed. Module 1: Relays and Contactors

16 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Theory of Operation Coil Specifications and Definitions Pick-up voltage - The minimum voltage that causes the armature to move Seal-in voltage - The minimum voltage that will keep the armature against the stationary core. Drop-out voltage - The voltage at which the armature starts to move away from the stationary core. Nominal coil voltage - The ideal voltage for which the coil is designed. A relay or contactor will typically operate properly when the actual voltage applied is 85 to 110% of the nominal voltage. Example: If the nominal voltage is 120v, then the typical operating range is volts. Module 1: Relays and Contactors

17 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Theory of Operation Coil VA rating The apparent power rating of the coil depends upon armature position and is specified as inrush and sealed. Inrush condition occurs when the voltage is applied to the coil but the armature has not moved completely against the stationary core. The sealed condition occurs when the armature is completely seated against the stationary core. Typical VA ratings for a standard relay or contactor coil could be 80VA inrush and 7VA sealed. For a coil with a nominal voltage of 120 volts, this translates to 667 mA inrush current and mA seal-in current. This difference in current from inrush to seal-in is approximately times greater. This large difference in current can be directly related to coil failure. This is due to excessive current in the coil if the armature does not become sealed properly or in a reasonable amount of time. Module 1: Relays and Contactors

18 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Theory of Operation As the term inrush implies, there is an inrush of current when the coil is initially energized. This inrush of current is the result of the armature position (unseated). When the armature is not seated, the impedance of the coil is low resulting in an excessive amount of current (inrush). Since the internal resistance of the coil is very low, the inductance of the coil is the main determining factor for the impedance. The inductance of the coil is directly proportional to the coil cores permeability. On the next pages we will discuss how permeability of the core affects the current in the coil. Permeability is a measure of a materials ability to concentrate magnetic flux. Relative Permeability is a measure of a materials ability to concentrate magnetic flux as compared to air (air being equal to 1) Module 1: Relays and Contactors

19 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Theory of Operation When the armature is not seated, the relative permeability of the coil's air core is very low (approximately equal to unity or 1). This results in low inductance, low inductive reactance, and thus low impedance. The following equation gives the relationship between inductance (L), relative permeability ( r ) and the coil size. A coil's inductance depends on how it is wound, the core material on which it is wound, and the number of turns of wire with which it is wound. 1. Inductance increases greatly as the number of turns of wire around the core increases since it is squared. 2. Inductance increases as the relative permeability of the core material increases. The relative permeability of air is approximately 1 and the relative permeability of an iron core is approximately times greater than that of air. 3. Inductance increases as the area enclosed by each turn increases. Since the area is a function of the square of the diameter of the coil, inductance increases as the square of the diameter. 4. Inductance decreases as the length of the coil increases (assuming the number of turns remains the constant). Module 1: Relays and Contactors

20 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Theory of Operation For the relationship below, if the number of turns, area of the core, and the length of the core all remain constant for a given coil; then the permeability of the coil's core is the determining factor for the inductance of that coil. For an air core ( r = 1), the inductance is very low. For an iron core ( r = 500), the inductance is very high. In this relationship, if the inductance increases, then the inductive reactance increases. If the inductance decreases, then the inductive reactance decreases. Inductive reactance is the opposition to AC current due to the inductance in the circuit. In the case of an air core, X L is very low, and the current in the coil is high. In the case of an iron core, X L is very high, and the current in the coil is low. Module 1: Relays and Contactors

21 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Contactor Applications Direct-On-Line Starting of an AC Motor This is the simplest method of starting AC motors. The expression "direct-on-line starting" means that the full electrical supply voltage is connected directly to the motor terminals, usually by means of a "contactor". Seal-in Circuit In order to comply with the requirements of the relevant regulations, a D-O-L starter comprises: 1. Efficient means for starting and stopping the motor. 2. Means to prevent automatic restarting (known as under-voltage protection or seal-in circuit) after a stoppage due to a drop in voltage or complete failure of supply, where unexpected restarting of the motor might cause injury to an operator. 3. A suitable device providing means of protection against excess current in the motor or in the cables between the device and the motor. This is known as "over-current protection". Module 1: Relays and Contactors

22 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Contactor Applications Module 1: Relays and Contactors

23 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Contactor Applications Direct-On-Line Reversing Motor starters are used when it is desired to reverse the direction of rotation of a three-phase squirrel- cage motor. The standard arrangement consists of a set of two, three pole; contactors operated electro- magnetically and mechanically linked together. They are usually controlled by three push buttons: Forward, Reverse, and Emergency Stop. The connections of one contactor reverse the supply voltage to two of the three motor terminals. Module 1: Relays and Contactors

24 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Contactor Applications Electrical and Mechanical Interlocking Opposing motions shall be electrically interlocked, as well as, mechanically interlocked. The mechanical interlock will not allow both forward and reverse contactors to be energized at the same time. If this could happen, 2L1 and 2L3 would be tied to T1 and T3 at the same time causing a short circuit. The electrical interlock (N.C. 1MF and 1MR) protects the coils for 1MF and 1MR. Example: If 3PB were pressed while the machine is running forward, inrush current would flow through 1MR coil. Since the mechanical interlock is stopping the contactor from closing, the moveable core stays open which would cause the coil to overheat and destroy itself. Module 1: Relays and Contactors

25 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Contactor Applications Design Techniques for Limit Switches There are many different techniques for limit switches when applied to a control circuit. The techniques and physical locations of the limit switches illustrated below are examples of recommendations and not requirements. 1. One technique is a limit switch used as a control stop device to prevent moving parts of machines from over-running the normal mechanical limits of the machine. Notice the location of 1LS in the circuit below. It is located in the right side of the schematic as a control stop device. The machine will stop when 1LS is actuated and is limited to that amount of travel only. This ensures that moving parts are brought to rest at the correct position. 1LS is using a normally closed (N.C.) contact for this operation. Control stop devices stop machines for normal operations. Module 1: Relays and Contactors

26 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Contactor Applications Design Techniques for Limit Switches 2. The configuration below is an example of the same circuit above except the limit switch is shown in the held position to represent the home position for the machine. 1LS is using a normally closed contact but it is held open (N.C.H.O.) to designate the home position. Module 1: Relays and Contactors

27 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Contactor Applications Design Techniques for Limit Switches 3. Another technique is a limit switch used as a control start device. To reverse the motion of the machine at the end of a stroke, 2LS is used as a control start device and is located in the middle of the schematic. Notice that 3PB is also a control start device for the reverse motion and 2PB is for the forward motion. Notice that 1LS and 2LS are used as control stop devices. When the forward motion moves the machine from the 1LS position to the 2LS position, the motor forward contactor will de-energize by 2LS (N.C.) and the forward motion will stop. Now 2LS (N.O.) also closes and will reverse the motion of the machine back to the home position (1LS). Module 1: Relays and Contactors

28 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Contactor Applications Design Techniques for Limit Switches 4. Another technique is a limit switch used as a safety stop device for safety conditions to be met before the machine can be started. Example: Limit switches on lift gates or guards protecting operators from moving parts of machinery. Notice the location of 1LS in this circuit. It is located in the left portion of the schematic as a safety stop device. Opening the gate or guard will stop the machine. 1LS is using a normally closed (N.O.H.C.) contact for this operation. 1 LS and 1PB are personnel safety stop devices. 1OL is an equipment safety stop device. Module 1: Relays and Contactors

29 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Forward-Reverse Contactor with Limit Switches to Control Stopping of the Opposing Motions Module 1: Relays and Contactors

30 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Automatic Forward-Reverse Contactor with a Limit Switch to Start the Opposing Motion Module 1: Relays and Contactors

31 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Simple Contactor with 2 Start Pushbuttons Module 1: Relays and Contactors

32 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Simple Contactor with 2 Start Pushbuttons Module 1: Relays and Contactors

33 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 This Concludes Module 1 Relays and Contactors Module 1: Relays and Contactors

34 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Module 2 Overload Relays Module 2: Overload Relays

35 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Construction Module 2: Overload Relays

36 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 O/L Specifications Operating Ranges Maximum Voltage: 600V AC or DC Frequency Range: up to 400 Hz Contacts: 1 Normally Open and 1 Normally Closed Ambient Temperature Compensation From- 4to140 °F -20to 60 °C Differential: Phase loss and phase unbalance detection Module 2: Overload Relays LR1-DO9LR1-D12LR1-D16LR1-D25LR1-D40LR1-D A A A A A 1-1.6A A 2.5-4A 4-6A 5.5-8A 7-10A 10-13A13-18A18-25A23-32A 30-40A 38-50A 48-57A 57-66A

37 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Adjustment and ResettingFunction Adjustment - Adjusting dial must be set to read the full load current of the motor (FLC). Resetting - Resetting is done by pressing the blue reset button after the bi-metal elements have been allowed to cool down. Module 2: Overload Relays

38 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Mechanical Operation. Module 2: Overload Relays

39 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Differential Operation Cold Position - The differential operators are hard over to the right Warm Position - NORMAL BALANCED CURRENT - The 3 bi-metals and the operators move to theleft the same distance d Warm Position - BALANCED OVER CURRENT - The 3 bi-metals and the operators move over to the left the same distance which trips the overload relay. Tripping current is 125% of the actual adjusting dial value Warm Position - UNBALANCED CURRENT - The unbalanced current causes unequal deflection of the 3 bi-metal strips. The differential lever amplifies this unequal deflection. The distance d is also amplified and causes the mechanism to trip. The tripping current for an unbalanced current is equal to 80% of the current for 3 balanced phases Module 2: Overload Relays

40 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Features Module 2: Overload Relays LR2D Bimetallic Overload Relays *Class 10 Protection to 140 Amps *Class 20 Protection to 80 Amps *With or Without Phase Loss and Phase Unbalance Protection *Ambient Temperature Compensated *High Resistance to Shock and Vibration *Proven Reliable Protection *Withstand in Excess of 17X Thermal Rating *Precise Settings by Graduated Dial *Separate Stop and Reset Functions *Manual/Auto Reset Selector *Setting Dial Cover can be Sealed *Trip Indication/Test Button on Front *Lockable Cover *Remote Reset - Remote Test *Direct Mounting to D-Line Contactors or Panel Mounting with Optional Bracket

41 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Features Module 2: Overload Relays Benefits B1-Stop function for instantaneous circuit isolation B2-Manual position for local or automatic position for B3-Provides visual indication of trip status B4-Easily adjustable trip range B5-Provides visual indication and protection against unwanted tampering of reset and trip settings B6-Provides flexibility in installations in control panels B7-Overload not affected by temperature Features F1-Separate Stop and Reset Function F2-Reset Button can be Switched from Manual to Automatic Position F3-Trip Test Button with Indicator F4-Full Load Current Trip Setting with Graduated Dial F5-Clear Cover for Manual/Auto Reset Selector and Trip Range Dial can be Sealed F6-Mounts directly to contactor or to bracket for panel mounting F7-Ambient compensated

42 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 This Concludes Module 2 Overload Relays Module 2: Overload Relays

43 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Module 3 IEC and NEMA Components Module 3: IEC and NEMA Components

44 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 IEC and NEMA Components The Organizations and Goals IEC - The IEC (International Electro-technical Commission) was conceived as an idea in 1904 during a meeting of the International Electrical Congress in St. Louis, Missouri. The first meeting of the IEC was held in London, England, in Its voting body consists of 42 member nations, each having one vote on the Commission. The United States is one of the voting members. Presently, the IEC is headquartered in Geneva, Switzerland. The IEC is international and its activities have traditionally been associated with equipment used in European common market countries. The IEC has developed recommendations to which manufacturers may test and publish technical information that provides potential customers with a basis for product comparison. "IEC Type" starters, contactors or overload relays refer to devices manufactured and tested per IEC recommendations. Module 3: IEC and NEMA Components

45 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 IEC and NEMA Components NEMA - NEMA (National Electrical Manufacturers' Association) was formed in 1926 and is headquartered in Washington, D.C. NEMA presently has 550 members, most of who are North American manufacturers of electrical and electronic products. The activities of NEMA have predominantly been associated with equipment used in North America. The primary goal of NEMA is to establish standardization within North American electrical industry. NEMA has developed product design standards and test specifications for device qualifications, many of which have been adopted by UL (Underwriters Laboratories). NEMA specifies the ratings a device must carry in order to be labeled with a NEMA designation. For example, a contactor must show motor ratings of volts and volts on its nameplate to be designated "NEMA Size 1." IEC and NEMA do not perform device testing. The manufacturers of the equipment do testing. IEC does publish parameters for life testing of contactors -- NEMA does not. The IEC life test does not state what the overall test results should be. However, they do recommend that the minimum electrical life of a contactor should be at least 1/20 of its mechanical life. "NEMA Type" devices refer to those traditionally supplied by the major U.S. manufacturers of motor controls. Module 3: IEC and NEMA Components

46 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 IEC and NEMA Components UL - Underwriters Laboratories was founded in 1896 as a private laboratory. Initially, its work involved testing equipment for insurance companies. UL directs its attention to verifying that an electrical product will not cause fire or shock when properly installed. The UL listing mark is significant to market acceptance of products in the United States. NEMA, UL or IEC does not dictate levels of electrical or mechanical life. In Europe and North America, the market dictates the level of device performance. Confusion can result when two devices showing the same horsepower rating are significantly different in size. The traditional NEMA type contactor, designed to provide a very high level of performance, is larger than the equivalently rated IEC type device. Size difference is more evident among contactors below 50 horsepower (at 460 volts). At 50 horsepower and above, the size difference is less evident because of the larger arc to be extinguished when the contacts are opened. Emphasis is placed on the small frame devices because 80% of the contactors and starters used in the world are less than 50 HP. These devices did not evolve differently because of IEC and NEMA. Market requirements influenced manufacturer design. To some degree differing economic conditions in the two parts of the world led to different market requirements and, as a result, different approaches toward the manufacture of electrical contactors. Module 3: IEC and NEMA Components

47 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 IEC and NEMA Contactors IEC Type - In Europe there has historically been relatively short supply and high cost of raw material. In the interest of conserving materials, designers considered the average application and used no more material than was required. This resulted in smaller size devices per horsepower rating, and therefore devices that are more application sensitive. Greater knowledge and care are necessary for proper application. NEMA Type - In North America, materials were plentiful and relatively inexpensive. The market demanded a very high level of performance throughout a wide range of motor applications. As a result, this eliminated much of the possibility of human error in application because it became extremely simple to select the appropriate device for a given application. Very rarely did the designer have to know any more than the horsepower and voltage of the motor to select the proper size device. Both types of contactors provide advantages. The designer makes the choice based on usage considerations. Module 3: IEC and NEMA Components

48 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 IEC and NEMA Contactors Application IEC type and NEMA type contactor application information and philosophy differ significantly. IEC type application information must be understood in order to achieve the desired level of device performance. IEC Type Contactors The primary function of the IEC is to recommend contactor test criteria and procedures which manufacturers may use to test and publish results. Published IEC type technical information is a statement of IEC recommended test results. A judgement must be made regarding how the laboratory test results actually relate to specific applications. One million electrical operations and a mechanical life of 10 million operations are generally accepted expectations for IEC contactors below 50 horsepower (These expectations are based on a standard squirrel-cage motor operating under normal conditions). Life expectations are less for contactors 50 horsepower and above. These levels of performance originated as a European market requirement for contactors. Module 3: IEC and NEMA Components

49 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 IEC and NEMA Contactors NEMA Type Contactors At the smaller horsepower ratings, electrical life expectations for traditional NEMA type contactors on tests per the IEC recommendations would be between 2.5 and 4 times greater than equivalently rated IEC type devices. Expectations vary based on manufacturer. In the middle sizes, the differences in expectations decrease. In the very large sizes, electrical life expectations of NEMA type and IEC type devices are about the same. NEMA type contactors provide a high level of performance for a wide range of applications, including some jogging duty. Some refer to that as extra or reserve capacity. Short Circuit With-Stand-Ability NEMA type contactors and overload relays are designed to withstand the let-through energy of a short circuit protective device available in the U.S. IEC devices were designed for coordination with fast acting European style fuses. Care must be taken in their application with slower acting U.S. fuses to avoid severe damage to circuit components Module 3: IEC and NEMA Components

50 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 IEC and NEMA Overload Relays NEMA Type Overload Relay The most common NEMA type overload relay is a stored energy, eutectic-alloy device (also called solder pot or melting alloy overload relays) that utilizes a special alloy that melts when damaging overload currents are present. This allows a ratchet wheel to spin free and release spring-loaded electrical contacts to de-energize the contactor and disconnect the motor from the line. The current in each phase of the motor is passed through a separate heater coil to heat an individual thermal unit containing the eutectic alloy. Because this type of overload relay senses current in each line independently, it will protect a motor from overload conditions as a result of single phasing or unbalanced currents. When the current in any one line exceeds the safe operating current for the motor, beyond the specified time limits, the overload relay will trip. The typical NEMA type overload relay utilizes interchangeable heater coils. This not only allows the device to easily and inexpensively be adjusted to protect motors of varying full load current at the same horsepower rating, but allows the same overload relay to be used with motors of a different horsepower rating, for different system voltages. Module 3: IEC and NEMA Components

51 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 IEC and NEMA Overload Relays IEC Type Overload Relay IEC type overload relays are bimetallic devices. A bimetal is made up of two strips or more of metal having different coefficients of expansion, attached together such that when heated, the metals expand at a different rate and cause the bimetal to bend. Motor current is utilized within the overload relay to heat three separate bi-metals, one per phase. An overload causes the bi-metals to operate a set of contacts, de-energizing the contactor and disconnecting the motor from the power lines. The IEC type overload relay is designed to provide single phase sensitivity. This sensitivity results in overload protection under single phase conditions. If one of the phases should be lost, one of the bimetal elements is not heated. The force it contributes toward operating the overload relay is also lost. The IEC type overload relay includes a mechanical means to compensate for this loss. As two bi-metals push forward, being heated by current, the differential operators sense this phase loss and cause the relay to trip. The IEC type overload relay is also designed to provide ambient temperature compensation. The overload relay is normally located in a different environment than the motor. Because of this, a fourth bi-metal strip is located in the overload relay to provide for ambient compensation for the temperature of its environment. A properly designed ambient compensating element reduces the effect on the overload relay caused by ambient change. This allows an overload relay of this configuration in a varying ambient temperature to properly protect the motor. Module 3: IEC and NEMA Components

52 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 IEC and NEMA Overload Relays IEC Type Overload Relay The IEC type overload relay is also designed to provide mechanical trip adjustment. This adjustment allows a particular overload relay to be used for a different range of motors. Most new type IEC overload relays are designed to be adjusted in the field for either manual or automatic reset operation. Module 3: IEC and NEMA Components

53 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 This Concludes Module 3 IEC and NEMA Components Module 3: IEC and NEMA Components

54 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Module 4 Control Relay Applications Module 4: Control Relay Applications

55 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Control Circuit Grounding Systems Control Voltages 24 Volt Control Circuit - This voltage is considered as a safe voltage and must be obtained by using an isolated type transformer (auto transformers are not allowed). It guarantees adequate protection for personnel and must be used in damp areas. 120 Volt Control Circuit - This voltage is not to be considered as a safe voltage and must be obtained by using an isolated type transformer (auto transformers are not allowed). Control System Examples 1. An ungrounded control circuit used with either a 24V or 120V control transformer. -The secondary side of the transformer is not grounded -The control circuit must be protected by two fuses Module 4: Control Relay Applications

56 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Control Circuit Grounding Systems Control Voltages - A ground fault at A, nothing happens. - A ground fault at A and B, the control devices between wire #1 and 6 are shorted out due to a current path around them. Therefore, the machine goes out of control. Contactor 1M is energized and neither the overcurrent relay nor the stop button can de-energize it. -A ground fault at A -and C, 6 Fu or 7 Fu, -and possibly both, -will open. This type circuit is not acceptable due to safety hazards. Module 4: Control Relay Applications

57 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Control Circuit Grounding Systems 2. A grounded control circuit used with a 120V center tap control transformer. - The center tap of the transformer is grounded. - The control circuit must be protected by two fuses. A ground fault at A, 6 Fu opens because there is a short circuit across the left side of the transformer. Contactor 1M remains energized if it was energized before the ground fault occurred, since 60 volts is enough to hold it in. Module 4: Control Relay Applications

58 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Control Circuit Grounding Systems - A ground fault at B, 7 Fu opens because there is a short circuit across the right side of the transformer. Contactor 1M remains energized if it was energized before the ground fault occurred, since 60 volts is enough to hold it in. In both cases the ground fault will not be noticed until the machine is stopped and an attempt to be started again. This type circuit is not acceptable due to safety hazards. Module 4: Control Relay Applications

59 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Control Circuit Grounding Systems - A ground fault at B, 7 Fu opens because there is a short circuit across the right side of the transformer. Contactor 1M remains energized if it was energized before the ground fault occurred, since 60 volts is enough to hold it in. In both cases the ground fault will not be noticed until the machine is stopped and an attempt to be started again. This type circuit is not acceptable due to safety hazards. Module 4: Control Relay Applications

60 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Control Circuit Grounding Systems 3. A grounded control circuit used with a 120V center tap control transformer and a ground fault relay (GFR). - The center tap is grounded through a 60 volt ground fault relay. - The control circuit must be protected by two fuses. Module 4: Control Relay Applications

61 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Control Circuit Grounding Systems A ground fault at A or B or C, the relay GFR gets energized and indicates the fault (1LT is on). The machine continues to function. This circuit is to be only used whenever the interruption of the machine causes product damage. An example would be a production area where the product would be damaged beyond repair if the cycle was interrupted and the cost would be very large. Module 4: Control Relay Applications

62 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Control Circuit Grounding Systems Note: A ground fault at A or B has to be repaired as soon as possible. If a second ground fault occurs on the left side of the coil (A or B whichever was first) the machine goes out of control. A ground fault at C also needs to be repaired as soon as possible because if a second ground fault occurs on the left side of the coil (A or B) 7 Fu and/or 8 Fu opens, which opens the circuit and interrupts the machine's operation. This grounded control circuit is considered to be safe as far as keeping good control of the machine's operation. But don't overlook that all metallic parts have to be grounded properly in order to protect personnel against electrical shocks. Module 4: Control Relay Applications

63 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Control Circuit Grounding Systems 4. Grounded control circuit used with a 24 volt or 120 volt control transformer. - X2 terminal of the secondary must be grounded. - One side of the coil must be connected to this terminal through a neutral link (1NL). Module 4: Control Relay Applications

64 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Control Circuit Grounding Systems - A ground fault at A, 6 Fu opens. No more voltage is applied to the control circuit. -A ground fault at B, nothing happens. The first ground fault occurring at the left side of the coil 1M will open the fuse 6 Fu and de-energize the circuit. General Conclusion The control system #3 is adopted for special applications only. The control system #4 is the one adopted by most manufacturers to control machinery. It has proven to be the safest for both personnel and equipment. Module 4: Control Relay Applications

65 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Control Circuit Grounding Systems Control Relay Master Circuit This circuit is designed to protect the system if any of the safeties in the circuit are activated. When the safeties are activated the CRM coil is de-energized which disables the rest of the circuit. The system would then have to be rearmed to allow the circuit to be restarted. Module 4: Control Relay Applications

66 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Control Circuit Grounding Systems Jog Circuits Using only pushbuttons to create a jog circuit will only work if the contacts change states a certain way. When the JOG button is pressed, the normally closed contacts have to break before the normally open ones close. When the JOG button is released the normally open contacts have to break before the normally closed ones close again. With most pushbuttons this causes a race problem with the contacts and sometimes the contactor will seal in even when jogging. The only way to insure that the contacts wont have a race condition is to use a separate control relay. Module 4: Control Relay Applications

67 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Control Circuit Grounding Systems Jog Circuits Using a control relay as below insures that the race condition is eliminated. Module 4: Control Relay Applications

68 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 This Concludes Module 4 Control Relay Applications Module 4: Control Relay Applications

69 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Module 5 Timers and Contact Blocks Module 5: Timers and Contact Blocks

70 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Timer Types The concept of using timers in electrical circuits is a very common practice. There are many ways to utilize timing functions and there are many types of timers. In this section the pneumatic type will be discussed and illustrated. Below are the two types which are used in common wiring practices. There is an ON delay type and an OFF delay type. Notice that there are two sets of contacts on each timer. One set is normally open and the other is normally closed. Above the contacts are shown with dotted lines between the normally open and normally closed set. This shows a mechanical connection between each set of contacts. This dotted line is not indicated on the schematic. There is a different method of showing that the contacts belong t o the same device. Once the timer is clipped onto the control relay, it becomes a timing relay. The designation for that is TR. If it is the first timer in the circuit, it becomes 1TR. Any contacts used from this timing relay will be called 1TR. There will be auxiliary contacts available to be used from this relay part of this timing relay. These contacts will not have any timing function. Module 5: Timers

71 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Timer Types For an example, if we use a relay that has 2 standard normally open contacts and 2 standard normally closed contacts as our timing relay, then those contacts will operate just as a control relay. We clip an ON delay timer on this relay. We have available to use 2 timed contacts, 1 normally open and 1 normally closed. A timer block can not function without a control relay. Module 5: Timers

72 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Pneumatic Timer Operation (Off Delay Type) Timer Initiation: When the coil is energized, the plunger will be pulled to the left by the movable magnetic circuit. The movable contact blade will then move from its rest position to the actuated position. Since the plunger is mechanically linked to the diaphragm, it will move left and compress spring A. The air contained in Chamber B is transferred into Chamber C through the opening D. This takes only a short period of time. The contacts change states almost instantaneously from their original positions. The N.O. contacts will close and the N.C. contacts will open. Timing Period: When the coil is de-energized, Spring A will push back the diaphragm thus creating a vacuum in Chamber B. Then the air contained in Chamber C will be forced through a metal filter. The airflow speed is regulated by a variable length groove fitted between two discs. This timing effect is obtained by varying the relative position of these two discs. The variation of the discs is made possible by a setting knob. Module 5: Timers

73 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Pneumatic Timer Operation (Off Delay Type) End of Timing Period: When the diaphragm returns to its original position, the contact blade snaps to the off position (rest). The N.C. contacts will close back to the original position and the N.O. contacts open to the original position. Module 5: Timers

74 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Pneumatic Timer Operation (On Delay Type) Timer Initiation: This happens when the coil is energized and not de-energized as in the illustration before. The N.O. contacts remain open and the N.C. contacts remain closed. Timing Period: When the coil is energized, the timing period begins. During the timing period the contacts remain in their normal positions. End of Timing Period: At the end of the timing period the N.O. contacts close and the N.C. contacts open. Module 5: Timers

75 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Pneumatic Timer Symbols and States Module 5: Timers

76 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Auxiliary Contact Blocks Auxiliary blocks are necessary when the control relay or contactor do not have the exact amount of contacts to do the job. Auxiliary contact blocks can also come in various types and configurations. Illustrated below is an auxiliary contact block with four sets of contacts and one with two sets of contacts. The four contact type could be 2 N.O.-2 N.C., or 4 N.O., or 4 N.C. and other variations. The two contact type could be 1 N.O.-1 N.C. or 2 N.O. or 2 N.C. As with the timer block, the auxiliary blocks can not function without a control relay or contactor. Module 5: Timers

77 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 This Concludes Module 5 Timers Module 5: Timers

78 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Module 6 Solenoids Module 6: Solenoids

79 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Understanding Solenoids Description: A solenoid is basically just an electrically-controlled valve that uses solenoid action to operate a mechanical valve. The voltage is applied to the terminals to redirect liquid or air flow. The solenoid valve usually has two or three ports on it: The main supply port The normally open (N.O.) port The normally closed (N.C.) port Normal means when power is not applied to the solenoid. Fundamentally the ports are arranged like this: A solenoid with only two ports would have either a normally open port or a normally closed port but not both. There are many other configurations for ports and piloting. The basic operation is only discussed. Module 6: Solenoids

80 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Understanding Solenoids Description: So, when the voltage is not applied, liquid or air can flow between the main supply port and the N.O. port. When voltage is applied, liquid or air can flow between the main supply port and the N.C. port. How the Solenoid Works When the voltage is applied to the solenoid coil, an electromagnet is created that moves a valve piston to direct liquid or air flow through the valve. A spring causes the piston to block the N.C. port until the voltage is applied to the coil. Then, the force of the electromagnet pulls the piston, closing the N.O. port and opening the N.C. port. Module 6: Solenoids

81 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 This Concludes Module 6 Solenoids Module 6: solenoids

82 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Module 7 Troubleshooting Power and Control Devices Module 7: Troubleshooting Power and Control Devices

83 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Troubleshooting Faulty Contactors In this section we will troubleshoot single direction and forward/reverse contactors with an ohm-meter. Each person should be allowed to perform these functions on actual devices. The single direction contactor contains: A coil, when energized it will change the states of all contacts Three main contacts (N.O.) used for switching power to the load (motor) One auxiliary contact (N.O.) used for the seal-in circuit To troubleshoot this device out of the circuit, the ohm-meter will be used. Troubleshooting the coil of a single contactor The ohmic reading for the coil will vary according to the size of the contactor. In this exercise, the smaller size contactor is demonstrated. Place the ohm-meter on the A1 and A2 terminals. If the coil is good it should read approximately 100 ohms for a 120v coil, and approximately 6 ohms for a 24v coil. Module 7: Troubleshooting Power and Control Devices

84 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Troubleshooting Faulty Contactors Module 7: Troubleshooting Power and Control Devices

85 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Troubleshooting Faulty Contactors Troubleshooting the main and auxiliary contacts of a single contactor The ohmic reading for the contacts should be approximately 0 ohms when closed and open loop (OL) when open. First, test the contacts for the de-energized operation. Place the ohm-meter on the L1 to T1 terminals. If the contacts are open, the reading should be OL. Continue to check the other two main contacts, L2 to T2, then L3 to T3. All should read OL on the ohm-meter. Then check the auxiliary contacts between terminals 13 and 14. The reading should be OL, also. To test the contacts for the energized operation, the contactor will need to be manually pressed to simulate the coil energized. Place the ohm-meter on the L1 to T1 terminals. If the contacts are closed, the reading should be 0 ohms. Continue to check the other two main contacts, L2 to T2, then L3 to T3. All should read 0 ohms on the ohm-meter. Then check the auxiliary contacts between terminals 13 and 14. The reading should be 0 ohms, also. Module 7: Troubleshooting Power and Control Devices

86 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Troubleshooting Faulty Contactors Module 7: Troubleshooting Power and Control Devices

87 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 The Forward/Reverse Contactor It contains: One coil for the forward direction and one coil for the reverse direction, when the coils are energized they will change the states of all contacts Three main contacts (N.O.) used for switching power to the forward direction Three main contacts (N.O.) used for switching power to the reverse direction One auxiliary contact (N.C.) used for the electrical interlock for the forward direction One auxiliary contact (N.C.) used for the electrical interlock for the reverse direction To troubleshoot this device out of the circuit, the ohm-meter will be used. Troubleshooting the coil of the forward/reverse contactor The ohmic reading for the coil will vary according to the size of the contactor. In this exercise, the smaller size contactor is demonstrated. Place the ohm-meter on the A1 and A2 terminals for the forward contactor. If the coil is good it should read approximately 100 ohms for a 120v coil, and approximately 6 ohms for a 24v coil. Then place the ohm-meter on the A1 and A2 terminals for the reverse contactor. If the coil is good it should read approximately 100 ohms for a 120v coil, and approximately 6 ohms for a 24v coil. Module 7: Troubleshooting Power and Control Devices

88 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 The Forward/Reverse Contactor Module 7: Troubleshooting Power and Control Devices

89 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 The Forward/Reverse Contactor Troubleshooting the main and auxiliary contacts for the forward/reverse contactor The ohmic reading for the contacts should be approximately 0 ohms when closed and open loop (OL) when open. First, test the contacts for the de-energized operation for the forward contactor. Place the ohm-meter on the L1 to T1 terminals. If the contacts are open, the reading should be OL. Continue to check the other two main contacts, L2 to T2. Then, L3 to T3. All should read OL on the ohm-meter. Then, check the auxiliary contacts (N.C.) between terminals 21 and 22. The reading should be 0 ohms. Module 7: Troubleshooting Power and Control Devices

90 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 The Forward/Reverse Contactor Next, test the contacts for the de-energized operation for the reverse contactor. Place the ohm-meter on the L1 to T1 terminals. If the contacts are open, the reading should be OL. Continue to check the other two main contacts, L2 to T2, then L3 to T3. All should read OL on the ohm-meter. Then check the auxiliary contacts (N.C.) between terminals 21 and 22. The reading should be 0 ohms. To test the contacts for the energized operation, the forward contactor will need to be manually pressed to simulate the coil energized. Place the ohm-meter on the L1 to T1 terminals. If the contacts are closed, the reading should be 0 ohms. Continue to check the other two main contacts, L2 to T2, then L3 to T3. All should read 0 ohms on the ohm-meter. Then check the auxiliary contacts (N.C.) between terminals 21 and 22. The reading should be OL. Module 7: Troubleshooting Power and Control Devices

91 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 The Forward/Reverse Contactor To test the contacts for the energized operation, the reverse contactor will need to be manually pressed to simulate the coil energized. Place the ohm-meter on the 1L1 to 1T1 terminals. If the contacts are closed, the reading should be 0 ohms. Continue to check the other two main contacts, 1L2 to 1T2. Then, 1L3 to 1T3. All should read 0 ohms on the ohm-meter. Then check the auxiliary contacts (N.C.) between terminals 21 and 22. The reading should be OL. Module 7: Troubleshooting Power and Control Devices

92 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Troubleshooting Faulty Control Relays with Auxiliary Contact Blocks In this section we will troubleshoot control relays with auxiliary contact blocks with an ohm-meter. Each person should be allowed to perform these functions on actual devices. The control relay contains: A coil, when energized it will change the states of all contacts Four main contacts (2 N.O.) and (2 N.C.) used for switching current and voltage in the control circuit To troubleshoot this device out of the circuit, the ohm-meter will be used. Module 7: Troubleshooting Power and Control Devices

93 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Troubleshooting Faulty Control Relays with Auxiliary Contact Blocks Troubleshooting the coil The ohmic reading for the coil will vary according to the size of the relay. In this exercise, the smaller size relay is demonstrated. Place the ohm-meter on the A1 and A2 terminals. If the coil is good it should read approximately 100 ohms for a 120v coil, and approximately 6 ohms for a 24v coil. Module 7: Troubleshooting Power and Control Devices

94 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Troubleshooting Faulty Control Relays with Auxiliary Contact Blocks Troubleshooting the main and auxiliary contacts The ohmic reading for the contacts should be approximately 0 ohms when closed and open loop (OL) when open. First, test the contacts for the de-energized operation. Place the ohm-meter on the 13 to 14 (N.O.) terminals. If the contacts are open, the reading should be OL. Next, place the ohm-meter on the 21 to 22 (N.C.) terminals. If the contacts are closed the reading should be 0 ohms. Continue to check the other contacts, 31 to 32 (N.C.), then 43 to 44 (N.O.). To test the contacts for the energized operation, the relay will need to be manually pressed to simulate the coil energized. Place the ohm-meter on the 13 to 14 (N.O.) terminals. If the contacts are closed, the reading should be 0 ohms. Next, place the ohm-meter on the 21 to 22 (N.C.) terminals. If the contacts are open the reading should be OL. Continue to check the other contacts, 31 to 32 (N.C.), then 43 to 44 (N.O.). Module 7: Troubleshooting Power and Control Devices

95 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Troubleshooting Faulty Control Relays with Auxiliary Contact Blocks Next, clip on the auxiliary contact block. First, test the contacts for the de-energized operation. Place the ohm-meter on the 53 to 54 (N.O.) terminals. If the contacts are open, the reading should be OL. Next, place the ohm-meter on the 61 to 62 (N.C.) terminals. If the contacts are closed the reading should be 0 ohms. Continue to check the other contacts, 71 to 72 (N.C.), then 83 to 84 (N.O.). To test the contacts for the energized operation, the relay will need to be manually pressed to simulate the coil energized. Place the ohm-meter on the 53 to 54 (N.O.) terminals. If the contacts are closed, the reading should be 0 ohms. Next, place the ohm-meter on the 61 to 62 (N.C.) terminals. If the contacts are open the reading should be OL. Continue to check the other contacts, 71 to 72 (N.C.), then 83 to 84 (N.O.). Module 7: Troubleshooting Power and Control Devices

96 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Troubleshooting Faulty Control Relays with Timer Blocks (On and Off Delay) In this section we will troubleshoot control relays with timer blocks with an ohm-meter. Each person should be allowed to perform these functions on actual devices. The ON delay timer will be discussed first. The control relay contains: A coil, when energized it will change the states of all contacts Four main contacts (2 N.O.) and (2 N.C.) used for switching current and voltage in the control circuit The ON delay timer contains: One set of timed contacts that are normally open and will time closed after the relay is energized (N.O.T.C.) and will instantaneously open back up after the relay is de-energized. One set of timed contacts that are normally closed and will time open after the relay is energized (N.C.T.O.) and will instantaneously close back after the relay is de-energized. To troubleshoot this device out of the circuit, the ohm-meter will be used. Module 7: Troubleshooting Power and Control Devices

97 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Troubleshooting Faulty Control Relays with Timer Blocks (On and Off Delay) Troubleshooting the coil The coil should be tested using the same procedure as before for the contactors and relays. Troubleshooting the ON delay timed contacts: First, test the timed contacts for the de-energized operation. Place the ohm-meter on the 67 to 68 (N.O.T.C.) terminals. If the contacts are open, the reading should be OL. Next, place the ohm-meter on the 55 to 56 (N.C.T.O.) terminals. If the contacts are closed the reading should be 0 ohms. Module 7: Troubleshooting Power and Control Devices

98 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Troubleshooting Faulty Control Relays with Timer Blocks (On and Off Delay) Next, test the contacts for the energized operation. Place the ohm-meter on the 67 to 68 (N.O.T.C.) terminals. The reading should still be OL. Press the timing relay in to simulate the coil energized. The timed contacts should close after the time dialed on the timer. When the timed contacts close, the reading should be 0 ohms. Release the timing relay and the contacts should open immediately. The reading should go back to OL. Next, place the ohm-meter on the 55 to 56 (N.C.T.O.) terminals. If the contacts are closed the reading should be 0 ohms. Press the timing relay in to simulate the coil energized. The timed contacts should open after the time dialed on the timer. When the timed contacts open, the reading should be OL. Release the timing relay and the contacts should close immediately. The reading should go back to 0 ohms. Module 7: Troubleshooting Power and Control Devices

99 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Troubleshooting Faulty Control Relays with Timer Blocks (On and Off Delay) The OFF delay timer will be discussed next. The control relay contains: A coil, when energized it will change the states of all contacts Four main contacts (2 N.O.) and (2 N.C.) used for switching current and voltage in the control circuit The OFF delay timer contains: One set of timed contacts that are normally open, will close instantaneously when the timing relay is energized and will time back open after the relay is de-energized (N.O.T.O.). One set of timed contacts that are normally closed, will open instantaneously when the timing relay is energized and will time back closed after the relay is de-energized (N.C.T.C.). To troubleshoot this device out of the circuit, the ohm-meter will be used. Troubleshooting the coil The coil should be tested using the same procedure as before for the contactors and relays. Module 7: Troubleshooting Power and Control Devices

100 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Troubleshooting Faulty Control Relays with Timer Blocks (On and Off Delay) Troubleshooting the OFF delay timed contacts First, test the timed contacts for the de-energized operation before the timing relay has been energized. Place the ohm-meter on the 57 to 58 (N.O.T.O.) terminals. If the contacts are open, the reading should be OL. Next, place the ohm-meter on the 65 to 66 (N.C.T.C.) terminals. If the contacts are closed the reading should be 0 ohms. Next, test the contacts for the energized then de-energized operation. Place the ohm-meter on the 57 to 58 (N.O.T.O.) terminals. The reading should still be OL. Press the timing relay in to simulate the coil energized. The timed contacts should close instantaneously. The reading should be 0 ohms. Release the timing relay and the timed contacts (N.O.T.O.) should open after the time dialed on the timer. When the timed contacts open, the reading should be OL. Module 7: Troubleshooting Power and Control Devices

101 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Troubleshooting Faulty Solenoids In this section we will troubleshoot solenoids an ohm-meter. Each person should be allowed to perform these functions on actual devices. The solenoid contains: A coil, when energized it will change the position of the mechanical valve The mechanical valve which could be normally open or normally closed, or both. A mechanical override is supplied with some valves To troubleshoot this device out of the circuit, the ohm-meter will be used. Troubleshooting the coil The ohmic reading for the coil will vary according to the size of the solenoid. In this exercise, the smaller size solenoid is demonstrated. Place the ohm-meter on the terminals of the solenoid. If the coil is good it should read approximately 100 ohms for a 120v coil, and approximately 6 ohms for a 24v coil. Module 7: Troubleshooting Power and Control Devices

102 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 Troubleshooting Faulty Solenoids Troubleshooting the mechanical operation of the valve If the valve is supplied with a mechanical override, operate the override to check the mechanical operation. If the valve is not supplied with a mechanical override, the appropriate voltage for the coil should be applied to the solenoid coil to check the mechanical operation. Module 7: Troubleshooting Power and Control Devices

103 Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 - Power and Control DevicesAuthor : IMS StafffCreation date : 02 Nov 2012Classification : D3 This Concludes Module 7 Troubleshooting Power and Control Devices Module 7: Troubleshooting Power and Control Devices


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