RCD Testing for Businesses

Residual current devices, or RCDs, are one of the most important safety devices in a commercial electrical installation. They detect current leaking to earth, for example through a damaged cable or a person touching a live part, and disconnect the supply in a fraction of a second. An RCD that is slow to operate, or does not operate at all, gives no protection, and there is no way to tell from the outside.

LC Electrical Services tests RCDs for offices, shops, schools, hospitality venues and industrial sites across South Tyneside and the wider North East. Our engineers use calibrated instruments to measure how quickly each device trips at its rated current, confirm it does not trip when it should not, and record the results so you have clear evidence of the condition of every device.

There are two kinds of RCD check, and businesses need both. The first is the push button test, which the user carries out by pressing the test button on each RCD. Manufacturers typically recommend this every three months, and it confirms the mechanism moves. The second is an instrument test by a competent electrician, which measures the actual disconnection time. Only the instrument test shows whether the device is fast enough to protect people.

Under the Electricity at Work Regulations 1989, those in control of commercial premises must maintain electrical systems so they do not cause danger. RCD testing forms part of every fixed wire test and EICR, but many sites benefit from testing in between, particularly where RCDs protect socket circuits used for portable tools, outdoor equipment or catering, or where there has been a history of tripping.

Nuisance tripping is one of the most common reasons we are called out. An RCD that trips repeatedly is usually doing its job, reacting to a fault somewhere on the circuit, but it can also be caused by too many items sharing one device, damp in an external fitting or an ageing appliance. Simply resetting it, or worse bypassing it, leaves the underlying problem in place. We trace the cause methodically, circuit by circuit, and give you a clear explanation and an itemised quote for the fix.

Older distribution boards often have a single RCD protecting many circuits, so one fault takes out lighting and sockets across a whole floor. Where that is causing disruption, upgrading to RCBOs, which combine overcurrent and residual current protection on each circuit, means a fault affects only the circuit it is on. We can price this as a planned upgrade following testing.

Testing is planned to keep disruption low. Each circuit has to be switched off briefly while its RCD is tested, so we agree an order in advance, protect IT and other critical equipment, and work out of hours where needed. On larger sites RCD testing can be built into a planned maintenance contract alongside PAT testing and emergency lighting checks.

Every visit ends with a written record of each device tested, its rating, its measured trip times and any failures, together with recommendations. Our engineers are part of a NAPIT registered business, use UKAS calibrated test equipment and work to BS 7671, so the records stand up to scrutiny from insurers, landlords and fire risk assessors.