Basic Domestic Installations
Most domestic installations in Sri Lanka use single phase and is supplied at 230V line to neutral.
Up to the energy meter belongs to the supply authority. Consumer’s installation starts from the main switch.
Final circuits are taken from the consumer unit (or distribution unit).
Wiring a final circuit
Loop-in method
Enables all joints and terminations in a single final circuit to be made at ceiling roses, switches or other accessories. This makes all joints accessible for testing and alterations. Each final circuit has both its live and neutral conductors terminating at the consumer unit. Wires are usually laid in PVC conduits.
Two-way switches
Used when it’s necessary to operate an equipment from 2 positions.
Final circuits for socket outlets
Socket outlets are wired in 2 ways.
Ring circuit
Each circuit commences from consumer unit (or distribution board) through an MCB (or fuse) of specific rating usually 30 A, loops into each socket outlet and returns to the same MCB (or fuse) in the consumer unit (distribution board).
Looping must be done for the live, neutral and the protective conductors in separate rings.
A ring circuit can only be used when:
- The floor area served by the ring does not exceed
- Maximum demand of the circuit doesn’t exceed the MCB (or fuse) rating
Radial connection
Each circuit commences from consumer unit (or distribution board) through an MCB (or fuse), loops into each socket outlet and ends at a socket outlet.