Background

Wiring a Distribution Board [DB] is vital in any electrical installation.All the electrical sub circuits are originated from a Distribution Board.The Main feeder cable to the Distribution Board should be able to handle the total power anticipated when all the sub circuits in the Distribution Board are in use. A Sub Circuit can be an electric cable distributing power to few lights, or a socket outlet/s through a MCB device or a Fuse in the Distribution Board. Here we are considering a Distribution Board with MCBs [Miniature Circuit Breakers] for power distribution.

Installation work described here is according to British Standards [ IEE Regulations and Practice ].

 

Accessory Requirement

12 Way Single Raw DB-01 nos

2 Pole-60A-30mA Trip Current RCCB-01 nos

2 Pole -60A- MCB-01 nos

1 Pole-10A-MCB-05 nos

1 Pole -20A-MCB-2 nos

1 Pole-16A-MCB-1 nos

Cu MCB Bus Bar segment-8 way

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Preparation

We are considering that the DB used here will power 5 nos. Lighting Sub Circuits,2 nos 13A Radial Circuits for Socket outlets and 01 nos. 16A Circuit for an AC unit. Each lighting sub circuit will be connected to about 8 nos. of Light points in this example. The rating for the DB is 60A, Single Phase, at 230V. So the Feeder Cable or the Main Incoming cable should be 16mm2 of cross sectional area for Phase and Neutral cables,which can be used for a 60A electrical load.

 

Method of Wiring

Sub Circuit wiring has been discussed in detail for 1W Light, 2W Light,5A ,13A and 16A Socket outlets etc. These needs to be wired prior to wiring of the DB unit so that when the DB is installed, these circuits can be connected to the DB.

DB Wiring and Installation.

The DB used will either be Surface mount or Flush Mount [ embedded] type. The enclosure will have entry points for connecting feeder cable and sub distribution cables on top and bottom sides. There will be many types of DBs in market but the example used here will enable the practioner to handle any type with ease.The DB has a DIN rail for installing RCCB,and MCBs. It also has two Cu Connector Bars , one for connecting all Neutral cables of the sub circuits and the other to connect all Earth earth cables used in socket outlets and electrical lighting fixtures.

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The Practical Way of Wiring the DB.

 

Example of Sub Circuit Wiring for 3 Lamp Points

 

Wiring Diagram for a 60A, Single Phase Distribution System with RCD unit

 

 

Wiring inside a Consumer Unit or a Distribution Board

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Devices used for the Consumer Unit

Devices used for a Single Phase 40A Distribution Board or a Consumer Unit

A Two Pole RCD unit used for 40A-30mA Tripping Current for 230 V Single Phase
installation

 

A Two Pole 40A MCB Unit for 230V , Single Phase Installation

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Arranging sequence of the devices for the Consumer Unit. The 2 Pole or the Double Pole MCB, the RCD and then the Single Pole MCBs

 

Inside look of a Single Raw Distribution Board. The two Link Bars on top are for the Earth and Neutral cable connectionsIn the middle, there is a DIN rail for fixing MCBs and RCD.

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MCBs and the RCD fixed on to the DIN rail. This is easily being done as there is a moveable latch in each MCB and RCD devices.

 

A piece of Copper MCB bus bar section which is used to link individual MCBs to the Main power.

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Bus bar segments entering MCB units

 

The completed Consumer unit with its outer flap open.

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This is how the connections to be done inside the Consumer Unit. Red denotes the Live wires and the Black denotes the Neutral wires.

 

The Detailed internal wiring for the Sample DB and MCBsand RCD units used.