Replacing an Electric Shower

[Stevejonesuk]

Hi could someone advise me on replacing my existing 7. 2 KW Gainsborough Shower with a new 8.5 KW Triton Shower? I am not experienced in electrical matters but it would appear I currently have 6mm squared cable to the existing shower with a double pole cord switch. The shower does not have its own trip switch in the consumer unit and power to the shower and shower switch is only turned off when I switch the mains switch off in the comsumer unit. The cable run is about 5 meters. Would it be safe to replace with the 8.5 KW model? Thanks in advance.

 

[dingodeano]

Cable size the equipment installed and the fuse / circuit breaker have a relationship. I'm concerned that you say your shower circuit does not have its own fuse or circuit breaker. Could you check ?
Is there maybe a smaller fuse board or fuse switch which you are referring to as the main switch? If you could post pic would be better to advise you.

 

[Stevejonesuk]

Hi, yes I tried each trip switch in turn and only the main trip switch (100A) turned off the power to my shower switch. Thanks.

 

[Stevejonesuk]

Sorry just read the second part of your post. I will have a look when I get home. It's the main switch in the consumer unit.

 

[dingodeano]

Hello Steve. Get an electrician out mate. If your correct Your 6mm cable is being fed direct from the main switch. Potentially very dangerous. Are you sure that there is no other smaller fuse boards or smaller fuse switches anywhere?

 

[Stevejonesuk]

I'm pretty sure I only have the one fuse box but I will double check. Thanks.

 

[PrenticeBoyofDerry]

I'm pretty sure I only have the one fuse box but I will double check. Thanks.

Is the meter and supply arrangement inside the house or in external wall cabinet? If outside check to see if the shower is protected from there.
Might be worth uploaded some photos of what you have in place, with cover on and off consumer unit, isolate the system prior to removing covers.

 

[Stevejonesuk]

View media item 55154 View media item 55155 View media item 55156 View media item 55157 View media item 55158

 

[Stevejonesuk]

I have taken pictuers of the power supply and consumer unit (above). I dont think there is anything for the shower.

 

[PrenticeBoyofDerry]

Which isolator do you open for the shower circuit to have no power, the one at the fuse board or the on the left of meter?
Really asking if you isolate at fuse board is shower still powered?
But isolating at the left hand isolator this cuts power off to shower and I assume everything else?
Does the shower go off, if you isolate any of the fuses?
Can you point out where the cable for the shower runs or is terminated to with regards to your photos?

 

[Iggifer]

which of those 4 breakers isolates the shower?

I'm guessing 1 or 3 (cooker / water heater respectively)

 

[Stevejonesuk]

Ah just realised it's the cooker breaker (40A )which the shower is switched off by.

 

[PrenticeBoyofDerry]

looking at the set up, I would be surprised (only a little) if the cooker circuit was a ring, would expect radial. But two lives terminated, turn cooker circuit off and see if that isolates your shower?

 

[PrenticeBoyofDerry]

Ah just realised it's the cooker breaker (40A )which the shower is switched off by.

Just a little bit quicker than me!
That's not good, the shower must have an independent circuit!
I suggest you purchase a RCD 30mA protected shower unit with a 40A MCB and have this connected external of the fuse board.
Something like this
http://www.screwfix.com/p/crabtree-2-way-fully-insulated-rcd-board-consumer-unit-for-shower/45235

 

[Stevejonesuk]

Cool would that support a 8.5 kw shower with the 6mm cable? Thanks