Replacing existing electric shower

[wisdom-17]

Hi all,

I have a Triton electric shower which was installed by someone else around a decade ago. It stopped working the other day so I opened the front cover to see if there is an obvious cause (I don't have much experience in this area).

Upon opening, it appears the main problem is the connection between the mains electric cable and the shower has burned/melted (see second pic). I know this is a serious safety issue and a fire risk. As you can see in the first pic, the shower power rating is 7.8-8.5kW.

I have a few questions to help me decide on what to do next:

• I'm trying to understand how the burnout/melting happened, is it because a thicker electric cable is required?
• How can I check what power my electricity supply can hold for the shower? I'd like to upgrade to a higher power shower if my current wiring/fuse can hold it.

Appreciate any guidance

 

[EFLImpudence]

The overheating was caused by a loose connection.
You will need to cut off the damaged cable and renew the connector block.

Whether a larger shower can be fitted depends on the cable size and fuse/MCB rating.

 

[JohnW2]

The overheating was caused by a loose connection.

Indeed. I know it's been asked/discussed before, but it seems amazing how commonly it is just the neutral connection - do people perhaps take neutral 'less seriously' when tightening things up?

Kind Regards, john

 

[EFLImpudence]

That has often been suggested, although it seems unlikely.

It does, though, seem to be the only explanation in this case - with the internal wiring side of the connector and terminal screw virtually undamaged.

 

[JohnW2]

That has often been suggested, although it seems unlikely. It does, though, seem to be the only explanation in this case - with the internal wiring side of the connector and terminal screw virtually undamaged.

Indeed, but it's hard to see what else the explanation could be in any case, given that is seems so common for only the neutral to be involved!

Kind Regards, John

 

[Alec_t]

seems so common for only the neutral to be involved!

I had a similar problem, caused by a loosened screw connection in the terminal block of a Mira shower, but it was the Live that was involved.

 

[JohnW2]

I had a similar problem, caused by a loosened screw connection in the terminal block of a Mira shower, but it was the Live that was involved.

Well, I suppose that it has to be the L sometimes

However, as I said, it seems extremely common that when someone reports overheating of just one conductor at its termination (in a switch, socket, shower or whatever) it is just the neutral that is affected. I don't think there is any conceivable electrical explanation for that - hence suggestions like the 'psychological' one I mentioned.

Kind Regards, John

 

[Luckyphil]

Dependant on Cable length from Consumer Unit , wether run surface or in Insulation etc etc , Circuit Breaker size

your existing Cable looks like 6.0mm T&E ( solid cpc) , you could stretch to maybe a 9.5kw Shower , but that would need a 40amp Breaker, though a 9.5kw shower pulls just over 41amps @ 230v / 39.5 Amps @ 240v

more info rqd

Phil

 

[JohnW2]

... a 9.5kw shower pulls just over 41amps @ 230v / 39.5 Amps @ 240v

It's nearly always the case that "a 9.5 kW shower" means that it draws 9.5 kW (as you say, about 39.6A) at 240V - in which case the current at 230V (which is what matters to the regs) would be about 37.9A (so, at that voltage, it would become about a "8.7 kW shower )..

Kind Regards, John

Kind Regards

 

[EFLImpudence]

your existing Cable looks like 6.0mm T&E ( solid cpc) , you could stretch to maybe a 9.5kw Shower , but that would need a 40amp Breaker, though a 9.5kw shower pulls just over 41amps @ 230v / 39.5 Amps @ 240v

Not so.

At 230V it would be 8.7kW and 37.8A

The resistance of the element is the constant.

 

[JohnW2]

Not so. At 230V it would be 8.7kW and 37.8A

Too slow - albeit I said 37.9A!

Kind Regards, John