Strange RCD shower isolator behaviour

[deanxxx]

Hi,

We had a shower installed a while ago by an electrician (I did the plumbing) which includes a 63A RCD about 1 meter away from the shower, inside a cupboard. All seems to be in order but I noticed today that when I do an RCD test it will only trip when the shower isolator is in the ON position. Also, when I test the RCD and trip it, the isolator neon stays ON even though the shower neon goes OFF.

My question are:

1) Is it normal for the RCD to only trip when the isolator is on? It don't seem right to me.

2) Should the isolator neon remain on after I trip the RCD with the test button? If so, where would it be getting it's power to supply the neon?

Strange indeed.

Thanx in advance for any help, regards,
Dean.

 

[deanxxx]

Ahhhhh, it just popped into my head.

The isolator is wired BEFORE the RCD. Of course, derrrr.

The RCD wont trip if the isolator is off because it has no power and the neon will always be on regardless on the RCD because it is "upstream" of the RCD.

Ok, my question is then: Do I need to swap the RCD and isolator around i.e. put the isolator in between the RCD and shower or does it not make a difference? Something tells me it would be better to have the isolator neon indicate the state of the RCD sort of thing.

Thanx/regards,
Dean.

 

[AndyPRK]

I'm glad you answered it!

It's certainly unusual but I would just leave it alone.