Something is tripping the board.

[harryspotter]

We have an outdoors double socket linked to an isolator for the hot tub. If I turn everything on, the electrics stay on for about 20 mins, then the rcb shuts off.

If I turn the hot tub off with the isolator, the rcb stays on.

We have had this set up for years, but a few months ago, we did have the sockets moved while rebuilding the wall.

This only started happening within the last month.

I opened the plug socket and it is a bit rusty in there.

It's either the sockets or the hot tub.

Any ideas?

Herenis a pic of the sockets, I just put some plastic over them temporarily just in case it's rain getting inside

 

[EFLImpudence]

the rcb stays on.

Do you mean RCD or MCB?

I opened the plug socket and it is a bit rusty in there.

Likely to be wet then. That could cause an RCD to trip.

It's either the sockets or the hot tub.

Ok.

Any ideas?

Here is a pic of the sockets, I just put some plastic over them temporarily just in case it's rain getting inside

Let us know how if it stops the tripping.

 

[Harry Bloomfield]

I opened the plug socket and it is a bit rusty in there.

If it's rusty, moisture is getting in - that is enough to trip an RCD.

 

[harryspotter]

Would it tripmit immediately? As I said, it takes about 20 mins.

 

[Harry Bloomfield]

Would it tripmit immediately? As I said, it takes about 20 mins.

If you doubt it, unplug what you have plugged in to that socket, and see if it still trips.

 

[ericmark]

There are three options with a hot tub outside, one is an earth mat, with a TT supply, the next is loss of PEN detection with a TN-C-S supply, and the third is to use a class II hot tub, so basically there is no earth. The other two mean so much work, that in the main option three is used, which means very unlikely an earth fault on the hot tub can cause an RCD to trip.

All other electrics in the area should be the same earth wise, but although the items are class II, the supply still has an earth.

But it seems likely the earth system is not as it should be, and to advise how to DIY repairs could result in danger due to the way it have been earthed.

Loss of PEN is rare, but with EV charging points and extra load on the system, it is becoming more common, read more here there have been some YouTube videos about the problem as well, but the main point is you need equipment which is unlikely to be available to DIY people.

 

[CountryFan]

Would it tripmit immediately? As I said, it takes about 20 mins.

Depends if there’s a load or just arcing. Can you provide photos with plastic covers removed?

 

[ebee]

It needs investigating by someone competant and using the correct test gear, it could be a dangerous situation.
You need a pro

 

[Harry Bloomfield]

It needs investigating by someone competant and using the correct test gear, it could be a dangerous situation.
You need a pro

The blue plastic bags, over the sockets, look extremely suspicious. Then attached to what appears to be a temporary structure. On the whole, it looks like a very amateur lash-up, potentially dangerous.