Difference between single phase wiring and three phase wiring

Building Service II

1. Difference between Single Phase Wiring and Three Phase Wiring Group Member: Penny Leung Tan Shen Shin Lim Hao Zheng Shum Wen Jun Benson Sow Wei Henn

2. Single Phase Wiring Single Phase Wiring The single phase requires two wires for completing the circuit, the conductor and the neutral. Peaks in voltage at 90⁰ and 270⁰, with a complete cycle at 360⁰ (see chart below.) With these peaks and dips in voltage, power is not delivered at a constant rate The single phase supplies the voltage up to 240 volts. It is mostly used for running the small appliances like a fan, cooler, grinder, heater

3. Three Phase Wiring The three phase system consist four wires, three conductors and one neutral. is continuous and never completely drops to zero. All three phases of power have entered the cycle by 120⁰. By the time a complete cycle of 360⁰ has completed, three phases of power have each peaked in voltage twice In basic terms, three-phase electricity means that electricity is delivered to your house using three power lines instead of one. Makes your house less risk to blackout Usually suitable for larger homes such a bungalows or semi-detached homes DELTA CONNECTION STAR CONNECTION

4. SINGLE PHASE SUPPLIES THREE PHASE SUPPLIES Take single lane highway as an example. Voltage power provided is limited Take multiple or 3 lanes highway as example. Voltage power provided is extremely high and running multiple appliances in parallel.

5. DIFFERENCE BETWEEN SINGLE PHASE WIRING AND THREE PHASE WIRING Malaysia 50Hz Single phase 240V 3-phase 415V 240V

6. Single Phase wiring installation

7. 3 phase wiring installation in multi-storey building

8. Advantages of Single Phase Wiring - The conductor can be quite lightweight and compact in size, which also results in the supporting tower becoming lighter. The unit is, overall, quite a portable one. EFFICIENT TRANSMISSION - The efficiency of the transmission increases, ensuring that the unit operates at its optimum. LESS SUBSTATION REQUIRED - The substations can also be located near to the high voltage grid, which reduces the initial cost of transmission.

9. Disadvantages of Single Phase Wiring - Insulation depends on the voltage of the unit, whilst the size of the wire will depend on the current. So, whilst the motor will run quite efficiently, it will be costly to insulate. HIGH INSULATION COST CANNOT HANDLE OVERLOAD NOT UNIFORM TORQUE - This is a result of the frequency and can affect operation quality. - If your application is likely to overload the system, this is not the best motor choice and you would be better off looking elsewhere.

10. For transmitting the same amount of power at the same voltage ,a three phase transmission line requires less conductor material . 3-phase induction motor is self-started and is more efficient . High in power to weight ratio .The size of 3-phase alternator is small and the overall cost of the alternator is reduced for the generation of power . The instantaneous power is always constant which results in smooth and vibration free operation of machine . ADVANTAGES OF THREE PHASE WIRING

11. High cost in repairing and to restore the service ,the spare unit cost is high when the 3-phase transformer is not working . Failure of one phase puts the entire transformer out of service . Complex system ,requires symmetrical components for analysis and operation . DISADVANTAGES OF THREE PHASE WIRING

12. Single phase wiring system Three phase wiring system “Generally, if you have 3 or fewer air-conditioning units, and each are between 1 – 1.5 horsepower, you should be fine with single-phase power. But if the horsepower of your ACs are higher, consider changing to three-phase to prevent power trips” – Ganesan , an electrician from  Megah Global Electrical and Construction .

13. Why should you go for three phase wiring instead of single phase wiring? The cost to install and maintain three-phase systems is substantially lower than that of single-phase systems. Three phase so you can split the loads, first phase is for lighting and fans etc ; Second phase is for mix, grinder, TV, and others; Third phase is for AC, Inverter system etc This makes your house less at risk of a blackout. If one of the power lines stops delivering power to your estate, your house may still have power because the other two lines may not be affected, hence you would get continuous power supply. “To upgrade from a single-phase power supply to a three-phase power, you will need to apply through Tenaga Nasional (TNB) as they will be the ones who will send contractors to test and evaluate whether if upgrading to three-phase power is a feasible option”. The upgrading process can take up to three weeks and the cost may starts from RM2,000 and can go as high as RM10,000 depending on the size of your house.

14. Thank You