3-Phase Electrical Wiring Installation at Home
3-Phase Consumer Unit Installation from Utility Pole to 3-Phase Energy Meter & 3-Phase Distribution board and How to Connect Single Phase & Three Phase Loads in a Three Phase Wiring Distribution System
Requirements
Three Phase Energy meter 1 No
Three Pole MCCB, 63A, 1 No
Double Pole, 63A, 30mA Trip Current RCD, 3 Nos
Double Pole MCBs, 63A, 3 Nos
Single Pole, 20A, MCB, 6 Nos
Single Pole, 16A, MCB, 3 Nos
Single Pole, 10A, MCB, 6 Nos
Distribution board cases, 3 Nos
Bus bar Link for Neutral Cable Connections
Cupper strips for MCB Common connection, 3 Nos
Briefing
Generally, Electric company installs Single phase energy meter for less than 7.5kW (10HP) load in domestic areas (consumer unit for home). If the limit is exceeded, then it’s recommended that install a 3-phaseenergy meter for Consumer units, when load is exceeds from 7.5 kW, then 3-phase electrical wiring is recommended in domestic areas (Homes)
Theory
We assume that we will only connect single phase load (Light points, fans, TV, AC etc.) in this three phase electrical wiring installation. In other words, we will not power up 3 phase motors because in our homes, we haven’t that kind of (three phase) loads. If three phase load exists in your home, then you can so. As we can see that the total load is exceeded the limit of single phase electrical wiring installation, that’s why we have to wire our distribution in three phase system.
Practical Procedure of Three Phase wiring of distribution board & installation
As we have learned the basic electrical wiring of bulb, fans etc (i.e. Sub-circuits and final sub circuits)
- First of all, connect the three-phase energy meter as shown in fig. ( if you don’t sure that how to wire a 3-phase energy meter, then check this simple method. How to wire a Three-Phase Energy Meter)
- Connect the MCCB (Moulded Case circuit Breaker) as main switch to the incoming three phases (R, Y, B) from 3-phase energy meter
- Now connect the outgoing phases (R, Y, B) from MCCB (Moulded Case circuit Breaker) to the DP (Double Pole MCB , RCD, SP (Single Pole MCBs and load) as shown in fig)
- Also connect the Neutral wires to RCDs and then to neutral links and then to specific loads (as shown in fig).
Click image to enlarge
Good to Know
You can also use a Four Pole MCCB instead of Three Pole MCCB. But you should connect the neutral in the last slot of that MCCB (Incoming and Outgoing like other phases) and then connect the outgoing neutral to cupper strip as shown in fig.
How to Connect Single Phase & Three Phase Loads in a Three Phase Wiring Distribution System
In the above 3-phase wiring system, load can be connected by this way
Click image to enlarge
Good to Know
In a Three Phase Wiring Distribution System;
Line to Line Voltage = 440V
Line to NeutralVoltage = 230V
I.e.
L1 to L2= 440V
L2 to L3= 440V
L3 to L1= 440 V
And
L1 to N = 230V
L2 to N = 230V
L3 to N = 230 V
in USA and other Countries
L1 to L2= 208V
L2 to L3= 208V
L3 to L1= 208 V
And
L1 to N = 120V
L2 to N = 120V
L3 to N = 120 V
General Precaution
- Disconnect the power source before servicing, repairing or installing electrical equipments and installation.
- Also use the proper cable in size with this simple calculation method ( How to determine the suitable size of cable for Electrical Wiring Installation)
- Never try to work on electricity without proper guidance and care
- Work with electricity only in presence of those persons who has good knowledge and practical work to deal with electricity
- Read all instruction and cautions and follow them strictly.
- The author will not be liable for any losses, injuries, or damages from the display or use of this information or try any circuit in wrong format so please! Be careful because it’s all about electricity and electricity is too dangerous
You May Also Read
https://www.electricaltechnology.org/2013/12/three-phase-electrical-wiring.html
