Heating element on SSR causing RCD/GFCI to trip

[nick9one1]

I'm trying to use to control a 350w heating element with an SSR.

Very simple

After about 3 mins the rcd/gfci trips. Initially I thought it was the heating element, so bought another. But it does the same. I have also tested the element directly wired to a plug, and It was fine for a good 10 mins.

So I think it must be the relay, except I've tried two, both cheap but rated well over the 350w (1.4Amps) the heater pulls.

The heating element is ceramic (not metal like the picture) So I dont think there can be any leak there. So It must be the grounded base of the SSR?

Any thoughts?

[DVDdoug]

Weird! Are you sure the neutral side is wired correctly?

So It must be the grounded base of the SSR?

What happens if you "float" it?

But, there shouldn't be any internal ground connection (or leakage).

[gilshultz]

Assuming it is connected as shown and powered with a battery you probably have a defective breaker. The CFGI breakers basically passes both the phase and ground through a donut transformer. With both the phase and ground they will cancel and nothing will be introduced into the transformer. If something conducts current via a different path and the ground and phase are not balanced it will trip. These devices do wear out.

The only other possibility is the heater, is it mounted on something that is grounded?

[rodgilmour]

Those SSRs need to be well bonded to a heat sink. I killed a one in no time with a 500W load.

[nick9one1]

You're right, but I dont think thats the case here. The ssr hasn't failed

[nick9one1]

I'm going to put one in a simple circuit with a battery and no earth path to see what happens.

[nick9one1]

Thanks, it could be. The GFCI is ~20 yrs old. I'll swap it out
The heater is actually ceramic, so non-conductive. And I've tried two - Both do exactly the same and trip the GFCI in 2-3 mins.