Hot tub tripping, but also working… crossed Neutral?

[JohnW2]

Yes. ... Yes.

Glad you agree.

Yes, it works. It is difficult to think of all the options.

I would dare to suggest that, in conceptual terms, there are not really any other 'options'. To be consistent with all the observed facts, I would stick my neck out and say that the 'only' possibility that the conductor marked as E in the vicinity of the downstream MCB must be connected to the N side of the upstream RCD (regardless of how that end of the conductor is 'identified'). Is that not the case?

Kind Regards, John

 

[JohnW2]

So in effect, it may be worth assuming the N and E wires coming from the main CU are in fact incorrectly labelled and are in reverse.
I guess I’ll try wiring these up the other way round as they are currently and see if this solves anything

As EFLI has said, NO. You must not change things around on the basis of speculative ideas as to what is probably wrong - even if we can't think of any other possible explanations, that speculation could be wrong.

You really must actually find out for sure, by testing, 'what is what', and then wire it all up correctly.

Kind Regards, John

 

[EFLImpudence]

I know my limits and opening up a multi-fuse CU is where I draw the line I think,
not confident in opening it up etc so will wait for Tuesday when I have a proper electrician round to examine it.

Ok.

I’m hoping it’s just as simple as the N and E being wrong way round,

Yes - somewhere.

my concern is if it is indeed wired up as it should be, (ie wires are labelled correctly) why the hell is it working when wired up with N and E the wrong way round… makes no sense!

It is because you are assuming (more than assuming) that the function of the wire is determined by its colour and not what it is actually doing.

is it possible in the current scenario this could occur if N and E were touching somewhere along the line?

No.

I think this was the situation at the beginning.
It must be like this because of the way it was behaving.

Apart from the Line mistake you have rectified, I think there must be two other mistakes which must be rectified to get it as it should be with colours representing the correct conductor throughout.

 

[EFLImpudence]

I would dare to suggest that, in conceptual terms, there are not really any other 'options'. To be consistent with all the observed facts, I would stick my neck out and say that the 'only' possibility that the conductor marked as E in the vicinity of the downstream MCB must be connected to the N side of the upstream RCD (regardless of how that end of the conductor is 'identified'). Is that not the case?

Yes, but as in my diagram that means there are two mistakes.

Do you agree?

 

[EFLImpudence]

And because of that Refinedgent has actually been correct in saying that the tub only works when N and E (not just Black and Grey) are the wrong way round.

This means that they must be the wrong way round somewhere else as well.

 

[Refinedgent]

Yes, but as in my diagram that means there are two mistakes.

Do you agree?

Ok,

I have a breakthrough!
It works!
I swapped downstream N and E (which appear to be in corrected labelled)
and everything now works as it should

I think as you all had cleverly determined, in essence there was a double issue of N and E being incorrectly wired at TUB (error 1) AND N and E downstream being incorrectly labelled (error 2)

Tub is now wired as indicated on the control panel,
and downstream RCD wired correctly Live actually passing through the RCD (not byapssing!)
AND the main input wires from the CU wired correctly (as they are incorrectly Labelled)

tub now functions perfectly, both RCD swicthes, also fully functional,
with a ‘local‘ 40A adjacent to Tub and a ‘remote‘ 32 Amp RCD on the CU in the outbuilding.
arguably this is actually unnecessary double protection as you only need a rotary switch adjacent to tub according to regs, but instead I can use the local 40Amp as a local switch.

Thanks all, looks like we got there in the end!

 

[JohnW2]

Yes, but as in my diagram that means there are two mistakes. Do you agree?

I agree with your diagram, but as for the 'number of mistakes', I suppose that depends on how one counts them.

There was, of course, at least one other mistake, namely the L path bypassing the downstream RCD!

Kind Regards, John

 

[JohnW2]

I have a breakthrough! It works! I swapped downstream N and E (which appear to be in corrected labelled) and everything now works as it should

In a sense, I'm pleased for you - although, as both EFLI and I have said, you really shouldn't have done that!

Kind Regards, John

 

[EFLImpudence]

Ok,

I have a breakthrough!
It works!

Ok.

I swapped downstream N and E (which appear to be in corrected labelled)
and everything now works as it should

Ok.
Which wire have you now connected to Earth on the tub?

I think as you all had cleverly determined, in essence there was a double issue of N and E being incorrectly wired at TUB (error 1) AND N and E downstream being incorrectly labelled (error 2)

Ok. I think.

Tub is now wired as indicated on the control panel,

What do you mean by that?

and downstream RCD wired correctly Live actually passing through the RCD (not byapssing!)

Yes.

AND the main input wires from the CU wired correctly (as they are incorrectly Labelled)

But How do you know that? They do not match the outgoing wires.

tub now functions perfectly, both RCD swicthes, also fully functional,
with a ‘local‘ 40A adjacent to Tub and a ‘remote‘ 32 Amp RCD on the CU in the outbuilding.

Ok.

arguably this is actually unnecessary double protection as you only need a rotary switch adjacent to tub according to regs, but instead I can use the local 40Amp as a local switch.

Yes.

Thanks all, looks like we got there in the end!

I hope so. I am not convinced.

How have you determined which is Neutral and which is Earth?

 

[Refinedgent]

Ok.


Ok.
Which wire have you now connected to Earth on the tub?


Ok. I think.


What do you mean by that?


Yes.


But How do you know that? They do not match the outgoing wires.


Ok.


Yes.


I hope so. I am not convinced.

How have you determined which is Neutral and which is Earth?

Connected up as shown. See image (black is now correctly wired to EARTH terminal in tub, Grey now to Neutral in tub, and brown to LINE 2 = Live in tub as it should be)
my multimeter is completely busted, but I remembered I had a simple pen tester (one of the ones that beeps rapidly and flashes when placed adjacent to Live and beeps slowly when placed adjacent to a Neutral (and is silent on Earth)

sure enough now pen tester beeps as expected on all wires.

so as it turns out though originally the colours indicated on the wires were a complete bloody mess and wholly incorrect.
The tub was actually wired ‘safely‘ albeit using only one point of protection of the RCD on the main CU and having a bizarre scenarios of an RCD being bypassed (in effect making it a rather over the top connection block) and the earth running through an RCD switch!

as such the reason it worked when it was wired ‘incorrectly’ was actually due to being wired wholly correctly just in a total bloody bodged manner with multiple wires incorrectly labelled

 

[Refinedgent]

In a sense, I'm pleased for you - although, as both EFLI and I have said, you really shouldn't have done that!

Kind Regards, John

Yep well aware, but frankly I was reaching end of my patience and didn’t want to shell out yet another call out fee, for what, after much chat here, very much Indictated a swapped N&E wire!

 

[JohnW2]

Yep well aware, but frankly I was reaching end of my patience and didn’t want to shell out yet another call out fee, for what, after much chat here, very much Indictated a swapped N&E wire!

Yes, I can understand that.

However, as I'm sure you understand, I wasn't 'criticising' you for effecting the corrections to the wiring yourself but, rather, for doing so before making sure that you really did know, for certain, which conductor was which (at both ends).

It does seem that our speculations were very probably correct but, as EFLI has said of himself, I don't think we can be totally 'convinced' that our theories/explanations are/were actually correct.

Kind Regards, John

 

[Refinedgent]

Yes, I can understand that.

However, as I'm sure you understand, I wasn't 'criticising' you for effecting the corrections to the wiring yourself but, rather, for doing so before making sure that you really did know, for certain, which conductor was which (at both ends).

It does seem that our speculations were very probably correct but, as EFLI has said of himself, I don't think we can be totally 'convinced' that our theories/explanations are/were actually correct.

Kind Regards, John

Yep totally, better to be safe then sorry! Though I was at the stage that I think I had genuinely exhausted every other possible Avenue.

unsure what tests to run to make sure it is now correctly wired up, as the tub is working, and wiring is now running through 2x rcds (both of which work, and when TEST button is pressed on either) they do indeed turn off tub and flip switch. Pen tester also appropriate indicates the wires as expected.
If I swap the Earth and Neutral now the systems shorts, so I’d say it’s pretty conclusive

 

[Harry Bloomfield]

unsure what tests to run to make sure it is now correctly wired up, as the tub is working, and wiring is now running through 2x rcds (both of which work, and when TEST button is pressed on either) they do indeed turn off tub and flip switch.

The normal way, would be to disconnect at both ends, check the insulation between all the poles, then 'bell' (check continuity) them out and mark them up with their correct identification. Despite it working, I would still suggest that is done.