Push the button

The importance of users regularly pressing the test button on RCD’s has been investigated in a recent report. Full report can be found here
Anecdotal evidence has always suggested that if the test button is not regularly operated, then RCD’s have been known to fail when they are needed most, and also under electrical test conditions.

The tests were carried out across 607 domestic properties in Housing Association and Local Housing Authority properties.
Various tests were carried out including trip time analysis at operating current, (30mA), 5 times operating current (150mA), repeated at 180 degree point of wave (POW) and manual operation of the test button.
In one Housing Authority, an electrician had shorted out a number of RCD’s due to nuisance tripping. No-one needs reminding this is 
dangerous practice and renders the RCD useless.

Pushing the test button on a regular basis, will not only ensure the mechanical operation of the RCD, but will highlight if the RCD has the potential
to fail in the event of a fault.

Whilst only a small percentage of the samples tested failed, the reason for the failures can be attributed to the test button not regularly tested.
The main reasons for failure are:

• Ingress of moisture and contaminants
• Component misalignment
• Severe disruption of the main contact surface likely to have caused contact welding

Regular testing would have detected such faults and the RCD’s could then have been replaced.
Occupiers need to be educated about the function of RCD’s and the importance of regularly operation of the test button.

Rob