New 8.5kw Shower

[djwestie]

I have spend a few hours reading about various issues relating to this, but can't find one that suits my issue. Here we go.

I had an 8.5kw wickes own brand shower ( made by Triton). 2 months ago i had my bathroom refitted & a new 8.5kw(Triton) shower installed. This worked fine until the weekend, since then it keeps tripping the RCD. My set up as below.

Cable from main fuse board (30a fuse) nothing else connected to this fuse ( say 3m of cable) into a switch on the wall outside bathroom. Then a cable from this switch ( again 3m ish) into the new shower, cable is around 6/7mm.

After reading the forum i am lead to believe the fuse should be rated @ 32A ?? But why is this problem only happening now, the old shower (same Kw) we had for 3 yrs without any issues.

We also have a fuse for the cooker rated 30A (i swapped these over) this didn't solve the problem.

Really need to know if this is a shower issue so i can call Triton or an electrics issue which would mean i call an electrician??

Thanks in advance

Westie.

 

[stem]

it keeps tripping the RCD

If an RCD is tripping, this indicates an earth fault and is nothing to do with the current rating.

 

[djwestie]

Stem thank you for your quick response. So i'm looking at an issue with the shower unit??

 

[bernardgreen]

If the RCD is tripping ( and NOT the MCB ) then the fault may not be with the shower. It might be a fault between Neutral and Earth on another circuit protected by the same RCD that protects the shower. Because the RCD only trips when the shower is used most people, including many electricians assume it has to be the shower that is faulty.

Neutral_Earth_trip

• bernardgreen
• 16 Jan 2011
• 48

 

[stem]

and NOT the MCB

There isn't an MCB

30a fuse

 

[djwestie]

Bernard, i do believe in my ignorant's i may well of got my RCD & MCB mixed up. The (Fuse) in the circuit breaker (labelled Shower) has a little button that keeps popping out when the shower is on for longer than 5 mins or so. At first you could push it back in & carry on showering, this morning i had to wait 5mins before the little button would stay pushed in.

As most ppl on forums i am looking at a cost effective way on fixing this ( just spend 4k) on the new bathroom. But will not do anything that would have any chance of cause electric shock/ fire!!!!

 

[Taylortwocities]

Need to clear up some terminaology here

Cable from main fuse board (30a fuse) nothing else connected to this fuse ( say 3m of cable) into a switch on the wall outside bathroom. Then a cable from this switch ( again 3m ish) into the new shower, cable is around 6/7mm.

So, where is the RCD in this circuit?

The (Fuse) in the circuit breaker (labelled Shower) has a little button that keeps popping out when the shower is on for longer than 5 mins or so.

Please post a photo of this device that 'trips'.

Thank you

 

[stem]

I had an 8.5kw wickes own brand shower ( made by Triton). 2 months ago i had my bathroom refitted & a new 8.5kw(Triton) shower installed. This worked fine until the weekend, since then it keeps tripping the RCD.

If you doubt its existence why did you post the diagram

 

[stem]

I may well of got my RCD & MCB mixed up.

30a fuse

...and your fuse!

 

[Taylortwocities]

Further. I think i might be beginning to understand what you are talking about.
Is the thing the trips like this?

ANd it is plugged into the fuseboard?

The things above are MCBs.

If this is the case then your new shower is pulling more curent than the MCB can manage.
An 8.5KW shower will pullmore than 35amps. That is why it takes a few minutes to trip.
The circuit breaker needs upgrading, but an electrician will need to confirm that the circuit is suitable for this.


Also, it sounds like you do not have an RCD, at all. You MUST have an RCD. The installation instructions for that shower says you must, wiring regulations say you must, and for you and your family's safety you must.

SO - electrician, fit RCD, upgrade the MCB to 40amp.

PS (and I know you will ask) cannot say why the old shower did not trip the electrics. Maybe Wickes were rather optimistic with their claim that the shower was 8.5KW

 

[Taylortwocities]

why did you post the diagram

Because he always puts that diagram up if anybody mentions the term RCD, even if it has nothing to do with the issue.

 

[djwestie]

Further. I think i might be beginning to understand what you are talking about.
Is the thing the trips like this?

ANd it is plugged into the fuseboard?

The things above are MCBs.

If this is the case then your new shower is pulling more curent than the MCB can manage.
An 8.5KW shower will pullmore than 35amps. That is why it takes a few minutes to trip.
The circuit breaker needs upgrading, but an electrician will need to confirm that the circuit is suitable for this.


Also, it sounds like you do not have an RCD, at all. You MUST have an RCD. The installation instructions for that shower says you must, wiring regulations say you must, and for you and your family's safety you must.

SO - electrician, fit RCD, upgrade the MCB to 40amp.

PS (and I know you will ask) cannot say why the old shower did not trip the electrics. Maybe Wickes were rather optimistic with their claim that the shower was 8.5KW

Thank you for this info. Yes you have it spot on. Looks like i need an electrician.

 

[djwestie]

Again thank you all for your help.

 

[bernardgreen]

Because he always puts that diagram up if anybody mentions the term RCD, even if it has nothing to do with the issue.

RCD was mentioned in the first post.

This worked fine until the weekend, since then it keeps tripping the RCD.

Too many "electricians" spend hours at the customer's expense looking for a fault in the wrong place because they are un-aware of the sneak circuit ( via a fault elsewhere ) that takes some of the Neutral current along the CPC to by-pass the RCD sensor.

 

[chivers67]

Further. I think i might be beginning to understand what you are talking about.
Is the thing the trips like this?

ANd it is plugged into the fuseboard?

The things above are MCBs.

If this is the case then your new shower is pulling more curent than the MCB can manage.
An 8.5KW shower will pullmore than 35amps. That is why it takes a few minutes to trip.
The circuit breaker needs upgrading, but an electrician will need to confirm that the circuit is suitable for this.


Also, it sounds like you do not have an RCD, at all. You MUST have an RCD. The installation instructions for that shower says you must, wiring regulations say you must, and for you and your family's safety you must.

SO - electrician, fit RCD, upgrade the MCB to 40amp.

PS (and I know you will ask) cannot say why the old shower did not trip the electrics. Maybe Wickes were rather optimistic with their claim that the shower was 8.5KW

If it is an old style board Aren't some of the old wylex a bit dodgy with 40 amp fuses installed? Maybe a Shower Unit with an RCD is required otherwise a complete new Board

Further. I think i might be beginning to understand what you are talking about.
Is the thing the trips like this?

ANd it is plugged into the fuseboard?

The things above are MCBs.

If this is the case then your new shower is pulling more curent than the MCB can manage.
An 8.5KW shower will pullmore than 35amps. That is why it takes a few minutes to trip.
The circuit breaker needs upgrading, but an electrician will need to confirm that the circuit is suitable for this.


Also, it sounds like you do not have an RCD, at all. You MUST have an RCD. The installation instructions for that shower says you must, wiring regulations say you must, and for you and your family's safety you must.

SO - electrician, fit RCD, upgrade the MCB to 40amp.

PS (and I know you will ask) cannot say why the old shower did not trip the electrics. Maybe Wickes were rather optimistic with their claim that the shower was 8.5KW

Thank you for this info. Yes you have it spot on. Looks like i need an electrician.

If it is an old style board some of the old wylex are a bit dodgy with 40 amp fuses installed.

Maybe something like this