Triton T90si(8.5KW)+tripping Mains

coxy123

In the last few days my electric shower sometimes, not all the time trips the main fuseboard. The MCB for shower has a rating of 40A. In order to return full power I have to trip shower MCB, I can then re-engae shower one at that stage. The shower is approx. 8 yrs. at this stage. Any ideas for what to check for /experiences would be welcome.

Tks.

M cebee

i can't quite follow the question

what is tripping? and how many showers do you have?

it might be damp or a 'heater' tank fault

or unlikely an overload

Bruthal

A bit confusing alright that question, possibly means the RCD is tripping, and to get it to reset, coxy123 is needing to switch of the shower`s 40 amp MCB.

The Shower RCD might also be the sockets one for a shower installed 8 years ago, so it can look like a lot of stuff is going off when it trips.

Sounds like a heating element or tank problem anyway, or moisture in the unit as m cebee says.

Try running the shower for a while with the heat off/shower set to cold and if it keeps going, switch to full heat while its still running, and see does that now trip it.

coxy123

Tks. for the replies.

It's the main isolating switch which trips - all power goes!

In order to restore full power I need to manually trip 'shower' MCB; once done I can restore full power again.

We have 2 of the same showers in house - used the 'other' one this morning twice and there was no issue with power - havn't tried other one since - could be to-morrow before I get a chance to have a look at.

Bruthal

Unless you have an RCD thats covering the entire house, the most that should go with the shower is the sockets. Are your lights and all going off?

Anyway, switching off the showers own pull chord switch or isolator switch upstairs should enable resetting without switching off the showers MCB. Put up a photo of the MCB board if you can.

coxy123

Hi Robbie7730 - Tks. for your help - I've attached a pic. of the fusebox - can't confirm if lights go off also TBH - will check this.

Bruthal

Ok, im guessing its the ELCB one thats tripping, and so your losing all your sockets, and then you assume all power is gone, but your lights should still be on in that case.

Its very likely there is a problem inside the shower unit. Usually its inside the heating tank. Try running the shower in cold mode, and see does the breaker stay on then, and then switch heat on to heat 1 for a minute, then heat 2, and see when it trips.

The likely outcome will be a new shower anyway, as being 8 years old it will not be worth replacing the likes of the heating tank in them, but moisture or burnt wiring inside the shower unit are a possibility which could be fixed, but usually the elements in the heating tank are the problem causing that ELCB(RCD) to trip if it is in fact that tripping. Very easy for electricians to check anyway.

You could remove the cover and have a look for any sign of burning or moisture, making sure the power is off at the board, and also have the pull chord switch off.

coxy123

Great response robbie7730 - Your right it is the ELCB that's tripping. I will take your f/back on board and let you know how things go.

M cebee

might be worth sticking in a rcbo
at the moment theres a c40 mcb and a 40amp rcd

and the 4pole contactor for manual changeover

Bruthal

If the shower 40 amp MCB cant be reset even with the problem shower not actually running, then turn off its pullchord switch, and see can it then be reset just to ensure the problem is after the pullchord.