As shown in the fig, the three phase, 400V (Three Lines + Neutral) service cable (from the secondary of Star or Y connected transformer (fed up by the secondary of delta connected power transformer) mounted on the utility (pole havin. As shown in the fig, the three phase, 400V (Three Lines + Neutral) service cable (from the secondary of Star or Y connected transformer (fed up by the secondary of delta connected power transformer) mounted on the utility (pole having 11kV voltage) and 3-phase kWh energy meter) enters to the main distribution board. All the three Lines (Phases) are. A distribution board is the combination of protective devices such as Main switch, MCB, MCCB, RCD, RCBO, Isolator, Fuses and Switchesetc. used to control and safely distribute the power supply to the electric appliances and devices. A distribution board is also known as main breaker box, electric panel or panel board used in commercial (as industri. Some of the readers requested in the page inbox as well as email to include the Old UK wiring color codes (UK now using IEC wiring color codes) for three phase and single phase distribution boards and consumer unit as the same wiring codes are still applicable in many countries including India, Pakistan, United Arab Emirate, Saudi Arabia etc. So, h. In a three phase distribution board, all the three phase, 400V load points can be connected directly to the three phases (L1, L2 & L3) with proper Earthing/Groundingwire. Keep in mind that Neutral is not always needed in a three phase system as it depends on the system design and operation. Three Phase 400V Appliances and MCB's 1. Three Phase Motor. We have used the following IEC wiring color codesfor 400V three phase supply voltage applicable in the UK & EU. IEC Wiring Color Codes for 400V, 3-Phase, 4/5-Wire System 1. Brown = Phase 1 or Line 2. Black= Phase 2 or Line 2 3. Gray = Phase 3 or Line 3 4. Blue = Neutral 5. Green or Green with YellowStripe = Earth or Ground wire as protective earth.
