By its very nature the work that we undertake is highly technical. The following are some of the technical terms that may come up in discussing or estimating a contract.
The national safety standard (British Standard 7671 - the IEE Wiring Regulations) requires every circuit to be protected by a circuit breaker or fuse which will automatically disconnect the circuit in the event of an overload or fault (such as a short circuit), to prevent fire and electric shock. In domestic premises, these devices are normally contained in the consumer unit (or 'fuse box'). The fault causing a circuit breaker is reset or the fuse replaced. It is essential that a 'blown' fuse is replaced by one of the correct rating - this rating should be clearly indicated on the fuse box.
Your electrical installation may incorporate one or more RCDs. An RCD is an automatic safety device intended to provide extra protection against electric shock. The national safety standard has for some years required any socket-outlet that may be used to supply portable electrical equipment outdoors, such as lawnmowers or electric drills, to be protected by an RCD with a rated tripping current not exceeding 30 mA.
Where a fixed RCD has been installed (such as in the consumer unit or a socket-outlet), there should be an adjacent notice that reads :
This installation, or part of it, is protected by a device which automatically switches off the supply if an earth fault develops. Test every three months by pressing the button marked 'T' or 'Test'. The device should switch off the supply and should then be switched on to restore the supply. If the device does not switch off the supply when the button is pressed, seek specialist advice.
“It is important that every RCD is regularly tested in accordance with this recommendation.”
Every electrical installation deteriorates over time, and should be inspected and tested at intervals to make sure it is safe, and is likely to remain so until the next inspection. It is recommended that electrical installations in homes are inspected at intervals not exceeding ten years by an NICEIC Approved Contractor. A notice recommending periodic inspection, and the date by which it should be carried out, should be fixed on or near the consumer unit.