Presentation on theme: "ECM-Driven Systems Industrial Systems How’s the GE ECM™ Motor different than an Induction Motor? Operation Construction The ECM’s Electronics The ECM's."— Presentation transcript:
ECM-Driven Systems Industrial Systems How’s the GE ECM™ Motor different than an Induction Motor? Operation Construction The ECM’s Electronics The ECM's Benefits and Advantages in HVAC Efficiency Constant Airflow Sound Tailoring to the Customer Programmability Installation and Serviceability Troubleshooting ECM-Driven Systems Set-up Replacing the Control Module Troubleshooting Guides Frequently Asked Questions GE ECM Motor is a trademark of the General Electric Company
ECM-Driven Systems Industrial Systems What's an ECM? The highest efficiency motor there is! … A DC Motor >Without mechanical Brushes and Commutator Permanent Magnet Rotor >Rotor losses are nearly zero Stator is driven from an Inverter, which, in turn, is powered from the AC line >The “Electronic Inverter” =“Commutates” the stator magnetic fields !Synchronous machine !Speed and torque controlled =Interfaces to the HVAC controls
ECM-Driven Systems Industrial Systems How’s an ECMDifferentThan a PSC Motor? The Rotor !Stator current produces magnetic field that acts on rotor: >Permanent magnets on rotor oppose stator field >No current flows in rotor >Rotor losses are very low >Torque is controlled by adjusting current in stator >Resilient isolation from shaft !Stator current produces magnetic field that acts on rotor: >Rotor “slips” in stator-produced field, inducing currents in rotor >Rotor currents create magnetic field to oppose stator field >Current in rotor causes I 2 R losses and heat >Limited torque control
ECM-Driven Systems Industrial Systems !Controlled by low voltage inputs >Permanently connected to AC line >Motor starts softly, ramps to speed >Wide airflow range between hi and low taps !Controlled by AC line >Start-up by contact to AC line >Abrupt turn-on stress, noise >Motor speed taps are inefficient and produce only minor speed adjustment How’s an ECMDifferentThan a PSC Motor? Operation and Application
ECM-Driven Systems Industrial Systems !In a series of tests the motor is “taught” the relationship between speed, torque, airflow and external static pressure. !“Airflow” is Programmed by the HVAC OEM and is specific and unique to the motor and air mover combination !Airflow is easily set up and trimmed at the installation =Uses an “Interface/Tap Board” and jumper or dip-switch settings !No other motor offers so many ways to control comfort and efficiency !Be sensitive to your customer …. “tailor” the airflow for him/her in his/her unique installation The ECM’s Benefits in HVAC Constant Airflow Capitalize on the unmatched flexibility of ECM-driven air movers ….. Offer “Tailored Comfort”.
ECM-Driven Systems Industrial Systems !Constant airflow over wide external pressure changes =Greater customer comfort and satisfaction !External pressure change causes: =airflow variation as filter loads =reduced performance =poor latent/sensible capacity control The ECM’s Benefits in HVAC ECMAirflow ControlPSC Overblowing the system poor moisture removal high power consumption PRESSURE Set the airflow level and go! System airflow is starved
ECM-Driven Systems Industrial Systems The ECM’s Benefits in HVAC Efficiency !PSC motor: =optimized only at rated design conditions =highest operating cost under most applied conditions. !ECM : =At 0.15” ESP (DOE rating point) : 2x the efficiency of the PSC =At 0.5”ESP (typical applied condition): 40% greater than PSC
ECM-Driven Systems Industrial Systems The ECM’s Benefits in HVAC Constant Airflow - How does the motor know what to do?
!Air noise dominates at high airflow, but ECM still has a slight advantage !ECM can get to lower airflow than PSC 6 times !At ~70% of rated airflow ECM is ~ 6 times quieter than at max airflow !Overall DBA: PSC motor at rated airflow-58.4 ECM motor at rated airflow-58.1 ECM (512rpm) - 39.4 ECM (600rpm) - 44.0 At low airflow, ECM has clear sound advantage over all other motor technologies (>14db quieter at ~1/2 capacity) The ECM’s Sound Advantage The ECM’s Benefits in HVAC
ECM-Driven Systems Industrial Systems The ECM’s Advantages For the Equipment Manufacturer !Improved system performance =Optimum performance and efficiency at design and rating conditions !Customer-tailored airflow at part load !Standardized motors and controls leverage volume and reduce inventory !Reduced engineering development time =Programmability =GE-supplied development system simplifies application =GE application support
ECM-Driven Systems Industrial Systems The ECM’s Advantages For the Contractor !Flexibility =Used with conventional 1-stage, 2-stage or variable capacity T‘stats =Conventional 24VAC interfaces !Field adaptable and serviceable =Wide cfm selection …. PLUS trim =Constant cfm simplifies installation =Capable of delivering proper airflow into applications with higher restriction =Replaceable controls make ECM repairable for the same price as replacing induction motors !Satisfied Customers =Perceptible, Saleable =Perceptible, Saleable performance and comfort =Tailor airflow to the customer’s preferences =Improve latent/sensible control
ECM-Driven Systems Industrial Systems The ECM’s Advantages For the Homeowner !Lower operating cost =Greatest applied efficiency of any system =Low stage and continuous fan airflows cost pennies to operate !Higher comfort =Low sound level Soft start-up Virtually silent low stage in 2-stage systems =Precise airflow gives better humidity/discharge temp control =Better filtration !Satisfaction in quality =Perceptible performance and comfort
ECM-Driven Systems Industrial Systems Installation and Service ECM Connections !5-Pin power connection !16-Pin control connection !Connector housing and control openings are “keyed” – properly insert connectors !Don’t let water run into connectors or openings !Be careful when probing connector and motor pins !Familiarity with ECM-to-system interface aids troubleshooting
ECM-Driven Systems Industrial Systems Installation and Service AC Line Gnd Lines 1&2 will be connected for 120Vac applications only !ECMs connect directly to the line =Do Not insert contactors/relays in series with either AC line !Control is powered continuously =insures reliable start-up =maximizes reliability !Pins 1&2 are jumpered in harness for Furnace (115V) operation =Line voltage should NEVER be applied to pins 1 or 2. !Make sure power is OFF before inserting or removing power connector !Verify and re-verify connector orientation before applying power !Plug is Polarized =Do Not force plug into motor Power Connection TIPS
ECM-Driven Systems Industrial Systems Installation and Service Power Connection TIPS !Furnaces/115Vac applications require series inductance in AC line =All 3/4 and 1hp applications will use inductor, 1/2hp may not =Reason: AC line currents are non- sinusoidal Inductor reduces peak line current Maintains circuit “ampacity” =Inductor should always be in line (HOT) side. !True RMS meters should be used to measure line current =Some clamp-on ammeters may not read line current accurately. !Remember -- the ECM’s current will be very low at off-load conditions because of its high efficiency. AC Line Gnd Lines 1&2 will be connected for 120Vac applications only
ECM-Driven Systems Industrial Systems Installation and Service Low Voltage Connections Through the 16-Pin Connector for cooling mode latent/sensible capacity control
ECM-Driven Systems Industrial Systems Installation and Service Control Connection Tips !24 VAC Inputs operate motor - like a conventional system =Functions G, Y, Y1, Y2, O, W will activate from 24Vac (R) Jumper R to G to activate fan at fan-only speed R to G to Y will activate fan to cooling speed G, Y, Y1, Y2 are on a threshold of 1/2 the “R” voltage. =Stats that “steal” power through Y or other functions are NOT compatible =Some solid state relays cannot turn off G and Y. !Don’t apply high voltage to control pins !Don’t apply 24Vac to Out+ or Out-
ECM-Driven Systems Industrial Systems Installation and Service Control Connection Tips !Make sure connector is fully seated !Make sure pins from harness are fully inserted into connector !Make sure transformer common(C) is tied to C1 and C2 !Pins 5, 11, 7, 4 access four Tables programmed into the motor: Heat Airflow Cool Airflow Start/Stop ramps and delays Airflow Adjust or Trim !Don’t apply high voltage to control pins !Don’t apply 24 Vac to Out+ or Out-
ECM-Driven Systems Industrial Systems Installation and Service !Use the manufacturer’s service and installation documents to set-up the system =Airflow VALUE (based on system capacity) must be set by switches =Adjustments to the cooling airflow are made =All of the motor connections should be understood Set Up TIPS
ECM-Driven Systems Industrial Systems Set-up must be done for ECM-driven systems to operate properly. Installation and Service Equipment Manufacturers use a variety of interface and set-up techniques: Shunts/Jumpers Dip Switches
ECM-Driven Systems Industrial Systems Installation and Service Set Up TIPS !Changing: =Heating airflow =Cooling Off delay =Cooling airflow require the unit to be cycled off before the change takes effect !Cooling Adjust or Trim changes take effect immediately
ECM-Driven Systems Industrial Systems Installation and Service Control Connection Tips !Interface/tap boards select the system’s airflow capacity and operating profiles. =Heating airflow @ pin 11 of ECM =Cooling airflow @ pin 5 of ECM =Profiles/Off-delays @ pin 4 of ECM =Airflow trim at pin 7 of ECM These settings must be made for the system to operate properly.
ECM-Driven Systems Industrial Systems Installation and Service Control Signal Measurement Tips !True RMS meters should be used !Presence of half-wave signals from interface board can be determined
ECM-Driven Systems Industrial Systems Installation and Service off !… “Y”, ”G”, ”W”, ”W2” are all off but the ECM is still running?... Now what?? !… the changeover valve signal (“O”) is not connected in a conventional air handler, so why is is it in an ECM-driven Air Handler? !… “ Y ” is not connected in the blower’s low voltage control box. What will the cooling CFM be? !… the dip-switch settings on the interface card are not changed at installation? !… dip-switches controlling cooling and heating capacity are changed but the CFM doesn’t change! !… there is no 24Vac on pin 12 of the ECM ’s 16 pin connector? What If…
ECM-Driven Systems Industrial Systems Installation and Service What If answers… off !… “Y”, ”G”, ”W”, ”W2” are all off but the ECM is still running?... Now what?? The system is probably being controlled by a thermostat that uses solid state relays or triacs as output switches. The current leaking through such switches can cause a voltage level to appear on the ECM Motor’s terminals that make it react as if the thermostat is actually calling. Another cause could be a high impedance compressor contactor or fan relay coil that causes a voltage above one-half the control transformer output voltage to appear on terminals “Y” or “G” of the motor. !… the changeover valve signal (“O”) is not connected in a conventional air handler, so why is is it in an ECM-driven Air Handler Unlike induction motor-driven systems, ECM driven systems tailor airflow in heating and cooling with separate airflows for each. The ECM needs to know the mode in which the system is operating to select the proper airflow.
ECM-Driven Systems Industrial Systems !… “Y” is not connected in the blower’s low voltage control box. What will the cooling CFM be? If “Y” is not connected, the ECM-driven blower will only respond to the “G” terminal in cooling. This means the blower will only operate at the “FAN- ONLY” air volume and will not change to the “Cooling” airflow required during compressor operation. The system will probably trip-off on high compressor head pressure or, if there is sufficient airflow to prevent that, the system’s capacity will be seriously degraded and will cause system reliability degradation and comfort complaints. !… the dip-switch settings on the interface card are not changed at installation? The dip switches on the interface card select airflow to match the size of the system installed. If they are not verified to be in the position matching the size of the condensing or heat pump unit, the indoor airflow will be grossly over-blown or under-blown. Also, the DELAY and TRIM functions will remain in factory default positions and may not be appropriate to the customer’s home, preferences or lifestyle. Installation and Service What If answers…
ECM-Driven Systems Industrial Systems !… dip-switches controlling cooling and heating capacity are changed but the CFM doesn’t change! In all probability, the switches were changed while the ECM-driven blower was running. The blower must go through an off-cycle for the new settings to take effect. !… there is no 24Vac on pin 12 of the ECM’s 16 pin connector? Without 24VAC from the low voltage transformer present at pin 12 of the ECM, the motor will not respond correctly to most of the control functions; specifically, “O”, “Y1”, “Y/Y2”. It is important that in all systems depending on these inputs that “R” be connected to pin 12 of the ECM. The “Analyzer” troubleshooting tool can pin-point that problem, if it exists. Installation and Service What If answers…
ECM-Driven Systems Industrial Systems Installation and Service !ECM airflow programs are specific to the motor, blower and cabinet combination — DO NOT EXCHANGE ONE MOTOR MODEL WITH ANOTHER Don’t exchange between different OEM products Don’t exchange between furnaces and air handlers !CFM - NOT SPEED - is commanded by the controls -- G, W, Y, Bk, etc… Constant Airflow TIPS !Speed and torque !Speed and torque change to hold CFM constant over a broad range of external static pressure
ECM-Driven Systems Industrial Systems Installation and Service Constant Airflow TIPS !Low static, high quality ducted applications will run slowly, quietly and efficiently….. while delivering the correct airflow. !High static applications will run fast, be noisy and power hungry …. The ECM may still provide the correct airflow, but at a price!
ECM-Driven Systems Industrial Systems Installation and Service !The motor program limits torque when a certain speed is reached =High static pressure will activate the torque limit =The motor will slow and airflow will fall off =In extreme cases huffing may occur !Solution -- Reduce the restriction!!! =Take out high pressure drop filters =Look for a problem in the #1 problem site in HVAC systems - the air distribution system Constant Airflow TIPS >The ECM can help a distribution problem, but BEWARE of EXTREME CASES! >Sometimes a problem can only be fixed at its source! Talk to homeowner about his ductwork >The ECM can help a distribution problem, but BEWARE of EXTREME CASES! >Sometimes a problem can only be fixed at its source! Talk to homeowner about his ductwork
ECM-Driven Systems Industrial Systems Installation and Service !Verify blower wheel is free and tight. !Verify line voltage at control connector -- both lines and ground. TIPS on Isolating the problem ! Use the HVAC SYSTEM and ECM ANALYZER to isolate the problem to the motor or controls.
ECM-Driven Systems Industrial Systems Installation and Service TIPS on Replacing the Control Module !If the motor doesn’t run... =Check out the motor per the procedure in the equipment manufacturer’s literature GED7161 or GED7161 !If the motor’s good, replace the Control only... =It’s cheaper and it’s faster! !Use the correct replacement module !While you’re there, look for other evidence -- Any Water? !If replacing an ECM2 control, use the Thru-Bolts and locater TAB that come with the replacement control !Make sure the control housing is centered and flush with the motor end-shield !Don’t over tighten - snug will do!