Have i got 10mm2 cable?

[iandavidcassidy]

my shower keeps triping after 5mins. so after 4 years of not using it, i have decided to fix it.

i have an older push-button Wylex fuse box and the MCB has a push button on it. the shower MCB is 30A

can i replace it with a newer style flip switch MCB from b&q of do i need to source an older style push button MCB?

also i have seen the wire going out of the box took the shower apart to see if it went into the shower. i think it is at least 6mm2 cable maybe more. but i have little knowlege. just looked at pictures of cable online.

it is the flat style of cable and looks huge next to the other wires . it measures exactly 10mm wide on the flat surface. does that mean the cable is rated 10mm2?

cheers

 

[securespark]

No.

//www.diynot.com/forums/viewtopic.php?p=201507#201507

 

[RF Lighting]

What is the rating of the shower (in kW)?

The MCB is probably tripping due to overload current. Unfortunatly 30A is the absoloute MAXIMUM size fuse which your fuse box can take. Anything bigger will cause severe damage to your fusebox.

Cable size can't be determined by measuring the outer sheath, and even knowing the CSA, we can't say how much current it can safely carry.

 

[iandavidcassidy]

my shower is 8.5kw...

so why is it triping - i read i need to change with a 35a 45a

where can i find an older fuse?

 

[securespark]

Unfortunately 30A is the absoloute MAXIMUM size fuse which your fuse box can take. Anything bigger will cause severe damage to your fusebox.

Has it tripped from new?

There could be an internal fault with something.

If it has not tripped from new, have the unit checked before suspecting the supply.

 

[Click-Sure]

Read RF's post again, even if you can find a larger MCB, if you were to use it with your consumer unit you'll be running a large risk of a fire (I've seen it happen through the same circumstance!)

The internal contacts and busbars and such were never designed to take more load than 30A.

 

[iandavidcassidy]

yes the unit has tripped from new.

would sourcing a replacement push 30a fuse fix it?

how would i check the shower? mayb i could just install a 8.5kw shower from b&q? and hope that fixes it.

 

[securespark]

If it has tripped from new, it is unlikely to be the unit. Not impossible, but unlikely.

It would have to have a major short between L & N or to earth to trip a circuit breaker. You'd need an insulation resistance tester to measure that.

That would tell you two things: the state of insulation within the shower unit and the state of insulation on the circuit.

If those were fine, then it would most likely be an overload causing the tripping.

Modern B type 32A breakers are slightly better at resisting overloads than the 30A (type 1 or 2) breakers: they are slightly bigger (extra 2A) and the characteristics mean it will accept a slight overload for a short period of time.

Maybe your breaker is not so forgiving.

I am not advocating changing the breaker as a sole means to cure the problem, just trying to explain why it may be tripping if there is no IR breakdown.

8.5kW at 240V (I know we use 230 for calcs, but 240 is a more real-world figure) is 35.5A.

Who installed the shower?

 

[iandavidcassidy]

errrm - dunno who installed it. my flat was a referb when i moved in. but i think at was a tad DIY refurb by the vendor.

i shall call an electrician then! i am useless at this..

unless it would help to but a push button fuse... (where could i get one?)

 

[mattylad]

Cursery reading of replies to you says:

No, nothing will help you, you cannot replace anything in your consumer unit to make this shower work.

Call an electrician out to give you a quote on the work that needs doing, you can then discuss what needs doing with him/her.

He/She should also explain to you that you will likely need a new consumer unit as your current one appears to be not upto the job, this will also mean you need the whole system tested before the new consumer unit is fitted.

Make sure that you are getting one that is certified to do domestic work to part p of the building regs.

So this may well be costly, however once done you will be able to stop smelling & take a shower, also have that feeling of safety knowing that your electrical wiring has been sorted & checked to be safe.

Or you could just continue to have baths [/b]