Question re RCD

[prhambly]

One of the trip switches in our consumer unit keeps tripping for no apparent reason. The switch in question controls lights and sockets upstairs, the oven, the immersion heater and the garage.

It often trips out when no-one is home, when the water heater was not being used (it never is). The only thing supplied that turns itself on and off is the freezer in the garage.

So, I plugged the freezer into one of those standalone RCD socket things.

Now when the CU trips, the RCD socket on the freezer trips as well.

My question is: does this prove that the fault in the freezer? Or could there be another explanation? The freezer seem to work fine otherwise

Thanks

P

 

[Echo the husky]

It depends, does the plug in RCD trip when the power to it is cut? If it does then it will not narrow down the fault, as it will go off when the house RCD trips.

The fastest way to find the fault is with an insulation resistance tester, especially as the fault is intermittent.

 

[prhambly]

Thanks for your reply. I've just turned the power off manually, and yes, that trips the RCD plug. So it's not necessarily the freezer.

Electrician, then....

cheers

 

[Echo the husky]

 

[deadshort]

Thanks for your reply. I've just turned the power off manually, and yes, that trips the RCD plug. So it's not necessarily the freezer.

Electrician, then....

cheers

Before you call an electrician, i would check all external lights and sockets for water ingress if you have outdoor electrics.

Regards,

DS

 

[ericmark]

You say garage so I assume not a frost free freezer? I say that as the minimum ambient temperature for frost free freezers is normally around 12°C so they need to be in a heated room during winter. The frost free freezer has a heater and these have been known to cause RCD's to trip, easy test move freezer to other RCD and see if tripping moves to other RCD.

Always test neutral to earth as well as line to earth, as often a switch or relay in the line so may not show fault. Also a near to neutral or neutral to earth fault can cause a large power user (that includes freezer because of start up amps) to trip the RCD when the fault is in a small amps user like the toaster, so unplug anything not being used. Switched off is not good enough as often neutral not switched, so has to be unplugged.