Help needed with RCD/Spa tripping

SuperRam · May 5, 2019

Hi all,

Hopefully this has posted in the right section.

Basically we have bought one of those inflatable spa’s. I also bought a BnQ pre wired outdoor socket.

The spa pump has a pre-wired plug with built in RCD.

I plugged this in too an outdoor socket which is pre-wired and has its own RCD plug which is plugged into the house.

It works for about 30 mins then trips. However if I plug the spa straight into a plug socket through the window the spa rcd is fine and doesn’t trip.

So what’s the problem outdoor socket rcd not working correctly? It does seem to get excessively hot.

I don’t mind paying for some one to wire a outdoor socket straight into the main electrics.....but will this fix the problem!

Hope that makes sense.

PEG · May 5, 2019

Hi,does the ground floor socket,you are using,belong to a a circuit which is protected by an RCD,in the "fuse board"?

SuperRam · May 6, 2019

Thanks so much for your reply.

Yes I believe it is. I base this on the fact there is an RCD switch/breaker in the fuse board which takes out all the plug sockets and some other circuits. I’ve checked it and it does turn off the plug sockets downstairs.

Also the dishwasher tripped the sockets a few weeks back as the heater element had packed up. So I am fairly confident the plug sockets are rcd protected.

Does this mean I could get ride of the rcd on the outside socket which plugs into the house and replace with a normal plug?

Thanks

HappyHippyDad · May 6, 2019

Hi SuperRam.
If you don't mind paying for an electrician to come out then this is going to be the best option. They will quickly be able to determine if it is a faulty outdoor socket or if you have an earth fault that needs finding. They will also be able to determine why the socket is becoming hot. It's just not worth messing around with unless you have a fair bit of electrical knowledge and some testing equipment (which includes insulation resistance testing).

telectrix · May 6, 2019

do not remove the RCD that's prewired in the spa lead. it's 10mA. this gives discrimination between the RCDs. should work fine although the 10mA RCD is prone to occasional tripping.your problem is most likely the plug-in outside socket. get a spark to fit you a permanent outside socket direct from the socket circuit in the house. the house RCD protects the circuit up to and including the outsidecsocket. the spa RCD gives further protection got the spa elecrics, and most importantly the people using it. the weakestcpoints incyour set-up are connections.... plug/socket etc. the fewer connections you have, the better. load (when heating) is 2.2kW (10A) so a proper installation will be trouble free.