Basic information on electrics in your home

Electrical Service and Meter

The electrical service to a property is supplied by either an overhead power cables or underground cables connecting directly into the ESB main fuse and ESB meter. These cables and meter are the property of the ESB. The service to most residential properties is single phase supplied by two conductors and delivers 240 volts of current to the property. Some larger homes and commerical properties have a three phase power supply supplied by four conductors. One neutral and three live and supply 380 volts of current to the property. A different meter is needed for this set up.

Main Electrical Panel

The main electrical panel in older houses would normally be a fuse panel unless the panel was upgraded. Panels in houses built in the last thirty years would have a breaker panel with trip switches. Fuse panels have been replaced by breaker panels since the 1970’s. The electrical panel is divided into separate branches known as circuits. Each circuit serves a separate area, system or appliance like a cooker. Each of these circuits should be protected by an over current protection device, which is either a fuse or a breaker. Sub-electric panels are provided when the main panel becomes overcrowded or when additional fixtures or extensions are added.


Most wiring used in properties since the 1950’s is PVC sheathed copper wiring and from the 1980’s multicore PVC /PVC copper wiring is used in most 20 amp circuits (and larger circuits). In older houses vulcanised rubber coated copper wiring can still be found. This wiring should be replaced.

RCD, Residual Circuit Detector, or ELCB, Earth Leakage Circuit Breaker

An RCD will give added protection to the electrical circuits within the property and is normally located in the main panel. An RCD will trip on an earth leakage of as little of 0.03 milli-amp and in a 40th of a second RCD’s should be rested regularly.

Plug Sockets

Plug sockets are normally fitted to walls and allow access to the wiring system. Plug sockets would normally be on a 20 amp breaker circuit. A small home would normally have a minimum of three plug socket circuits, one for the kitchen and one for the downstairs rooms and one for the first floor rooms.

Light Circuits

Light circuits would normally be on a 10 amp breaker. There would normally be a separate circuit for each different floor level in a typical house.
Light circuits would not be controlled by the RCD detector as they would likely to keep tripping the RCD breaker.

Outdoor Components

Exterior components and wiring should be weather proofed and use outdoor protected electrical wiring and fittings.