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Comprehensive coverage of mechanical systems, electric al systems, plumbing, fire protection, security, vertical transportation, lighting, acoustics and.

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Presentation on theme: "Comprehensive coverage of mechanical systems, electric al systems, plumbing, fire protection, security, vertical transportation, lighting, acoustics and."— Presentation transcript:

1 Comprehensive coverage of mechanical systems, electric al systems, plumbing, fire protection, security, vertical transportation, lighting, acoustics and communications. The course includes analysis techniques and design principles for each system. A comprehensive design project is required for a major building project.. Psychrometry and process of air. Cooling load estimation. Refrigeration cycles. Water chiller systems. Air handling system. Cooling towers. Equipment selection. Installation, operation and maintenance of air conditioning systems. Basic knowledge of data communication: data transmission technology, transmission media, signal interference, etc. Network topology: logical aspect and physical aspect. Local area network technology. Networking equipment: repeaters, signal transceivers converters, switches/hubs, connectors/interfacing equipment, etc. Principles of lighting, lighting design for buildings which includes artificial lighting, point, line and area light sources, types and properties of luminaries, polar curves, design methods and calculations, glare index, lighting design standard, luminaire heat recovery system and lighting energy management, hybrid lighting, daylighting of buildings, effect of climate on lighting T0- 1

2 PART ONE ELECTRICAL Chapter 1 Electrical fundamental T0- 2

3 3 Electricity Development can be measured by a nation’s electricity consumption Electricity usage is divided into: a)Industrial b)Commercial and residential c)Agriculture and irrigation Electricity important input for industry General Electricity

4 4 Electricity How can electricity supply shortage be solved? a)Renovation and modernization of plants, transmission and distribution systems b)Demand side management with the utilization of energy efficiency technologies c)Awareness raising among energy users General Electricity

5 5 Electricity Generation & Distribution Generator 10.6 KV GT 220 KV Step down transformer Distribution Power plant Transmission system Distribution system 380/220 V 22 or 11 KV

6 6 Electricity AC generators (“alternators”) generate electricity Electricity generated at 9-13 KV Power generated from 67.5 to 1000 MW Power stations: generating transformers (GTs) to increase voltage to KV Substations: step-down transformers to reduce voltage before distribution Generation & Distribution

7 7 Electricity Benefits of high voltage transmission Less voltage drop: good voltage regulation Less power loss: high transmission efficiency Smaller conductor: lower costs Generation & Distribution

8 8 Electricity Single phase AC circuit: Two wires connected to electricity source Direction of current changes many times per second Phase of Electricity 3-phases of an electric system (Wikipedia contributors, 2005) Three phase systems: 3 lines with electricity from 3 circuits One neutral line 3 waveforms offset in time: cycles/second

9 9 Electricity Star connection Phase of Electricity Delta connection

10 10 Electricity Active power (kW): real power used Reactive power (kVAR): virtual power that determines load/demand Utility pays for total power (kVA) Active and Reactive Power Source: OIT kVA =  (KW) 2 + (KVAR) 2

11 11 Electricity Power Factor Correlation

12 12 Electricity kVAR demand should be as low as possible for the same kW output PF Correction: Capacitors Figure: Capacitor as kVAR generator

13 13 Electricity Act as reactive power generators Reduce reactive power Reduce total power generated by the utilities PF Correction: Capacitors Electrical Systems/ Electricity Figure: Fixed capacitor banks Source: Ecatalog

14 14 Electricity Advantages for company: One off investment for capacitor Reduced electricity costs: Total demand reduced No penalty charges Reduced distribution losses Increased voltage level at load end, improved motor performance PF Correction: Capacitors

15 15 Electricity Advantages for utility: Reduced reactive component of network Reduced total current in the system from the source end Reduced I2R power losses Reduced need to install additional distribution network capacity PF Correction: Capacitors

16 16 © UNEP 2006 Electricity Goal: reduce maximum electricity demand to lower the electricity costs Load curve predicts patterns in demand Electrical Load Management Daily load curve of an engineering industry (National Productivity Council, India) KVA Hours

17 17 Electricity Strategies to manage peak load demand: Shift non-critical / non-continuous process loads to off-peak time Shed non-essential loads during peak time Operate in-house generation or diesel generator (dg) sets during peak time Operate AC units during off-peak times and utilize cool thermal storage Install power factor correction equipment Electrical Load Management

18 18 Electricity Energy charges Actual charges based on active power Charge based on apparent power Maximum demand charges Based on maximum demand registered Penalty for peak load Electricity Billing Mechanism

19 19 Electricity Power factor penalty or bonus Fuel costs Electricity duty charges Meter rentals Lighting & fan power consumption Time of Day (TOD) rates Electricity Billing Mechanism

20 20 Electricity Electricity Billing Mechanism Utility uses trivector meter for measurement during billing cycle (usually month): Maximum demand Active energy in kWh Reactive energy in kVArh Apparent energy in kVAh

21 21 Electricity Electricity Billing Mechanism Demand measured in time intervals Maximum demand is highest reading Customer charged on highest maximum demand value! A Typical Demand Curve (National Productivity Council)

22 22 Electricity Static electrical device that transforms electrical energy from one voltage level to another Two or more coils linked magnetically but electrically insulated Transformer Turns Ratio: turns on 2nd coil (connected to load) turns on 1 st coil (connected to power source) Figure 12: A view of a transformer (Indiamart.com)

23 23 Electricity Transformers are classified based on: Input voltage Operation Location Connection Transformer types

24 24 Electricity Electricity is the flow of electrons in a conductor. The electrons must have a path to and from its source. This path is called a circuit.

25 Normal, Open and Short Circuits Normal Circuit ◦ When normal current is flowing through the circuit Open Circuit ◦ When the current flow is interrupted by switch or fuse ◦ Circuit break presents an extremely high resistance. Short Circuit ◦ When the current flowing through the circuit is following a “shorter” low resistance path between the power source terminals. ◦ Allows high current to flow in the circuit T0- 25

26 Electricity  Various electrical devices are used as a part of the circuit.  These devices are used for a variety of activities, such as turning the electricity off and on, providing electricity to various lights or appliances, etc.

27 Types of Electrical Currents  Electrical current comes in two forms: ◦ Direct current (DC)  Flows in only one direction.  It is usually generated by battery-base electrical systems and used in the electrical systems of internal combustion engines or flashlight batteries. ◦ Alternating current (AC)  Reverses the direction of flow of current many times each second.  AC is the type used in homes, factories, etc.

28 Electrical Service  Service is provided to homes, businesses and other small users of electricity by three wires from a utility pole.  Two of the wires are “hot,” each carrying 220 volts.  The other wire is “neutral,” and provides the return path for electricity.

29 Electrical Service (cont.)  These wires are connected to a service entrance, which is where the electricity enters a building.  A meter is used in the service entrance to measure the amount of electricity being used.

30 Electrical Service (cont.)  The service entrance is grounded with a wire connected to a ground rod driven several feet into the ground.  It is needed to provide a return path to the ground and to carry away stray electrical current out of the system.

31 Service Panel  Follows the meter.  It houses the circuit breakers for the system and is used to distribute the power to individual circuits throughout the system.

32 Overcurrent  When a circuit uses too much electricity, an overcurrent causes a circuit breaker to trip, shutting down the power to that circuit.  The excessive heat caused by an overcurrent condition may burn or damage a conductor’s insulation and cause a fire.  A circuit breaker is a heat-sensitive switch, which automatically trips when electricity demand is too great which causes the temperature in the conductor to get too hot.

33 Amps Volts Watts The following relationship exists between Amps, Volts and Watts.  Amperes are a measure of the rate of flow of electricity in a conductor.  Volts are a measure of electrical pressure.  Watts are a measure of the amount of energy or work that can be done by amperes and volts.

34 Amps Volts Watts (cont.) Thus, the following relationship exists. Work = Pressure x Flow Or Watts = Volts x Amperes

35 Amps Volts Watts (cont.)  This formula is commonly referred to as the West Virginia Formula W=VA  When we know any two variables of the formula, we can calculate the other.

36 Amps Volts Watts (cont.) Formulas Watts = Volts x Amps Volts = Watts / Amps Amps = Watts / Volts

37 Calculating Amperage If we have a 100 watt lamp plugged into a 120 volt receptacle, we can determine the rate of flow or the amperes for that circuit. Amps = 100 Watts / 220 Volts 100 / 220 =.4545 Amps

38 Calculating Watts If a water heater operates at 20 amps on a 240 volt circuit, what is the wattage of the appliance? Watts = 220 Volts x 20 Amps 4800 Watts =220V x 20A Watts=4400

39 Calculating Volts If an electric motor operates at 2880 watts and 12 amps, what would be the voltage requirement for that motor? Volts = 2640 Watts / 12 Amps 2640 / 12 = 240 Volts

40 Maximum Minimum Average Find the max and min load of the following domestics daily curve T0- 40 Hour Kw

41 T0- 41

42 Transformer Rating T0- 42

43 Example Design T0- 43 Numbe r powerPower factor Dishwasher12.5 KW0.7 Air condition35 hp0.6 Water heater14 KW1 Washer16 KW0.8 Lighttotal7 KW1 1.High rising building consists of 12 level Each level 4 flats (4 bed room, reception and two bath room) If each flat has the following equipment The main building has the following 3 lefts15 hp0.8 pf 3 water pump12hp0.7 pf Outdoor light 10kw1 pf Calculate Total power design the electrical installation of the building Main cable and branch cable cross section Switchboard main and sub switchboard flat switchboard No of transformer

44 T0- 44


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