Shower cooking fuse?

[g60kg]

Hi all, I have tried to look for the answers but still need a bit of clarification.

I have cartridge type fuses and the shower has a 30amp fuse. It also has a 30amp circuit breaker thing which does not trip when the fuse is cooking.

I bought the house 6 months ago and it has been fine until recently. The wiring doesnt really look cowboy and Im pretty sure it 10mm.

Is it a simple matter of changing the fuse for a 45amp or is it something more complicated

 

[luminaire]

What size is the shower?

 

[g60kg]

What size is the shower?

thats one thing I forgot to find out, can you give me a couple of scenarios based on what it is likely to be...it doesnt look too old dont know much about them to be honest

 

[Adam_151]

Likely to be more complicated, there is the usual thing of verifying the capability of the circuit, but with older boards, its quite possible the board was never designed for a circuit greater than 30A... can you take a pic?

As the above poster states we also need to know the rating of the shower

 

[IJWS15]

"It also has a 30amp circuit breaker thing which does not trip when the fuse is cooking. "

Is this by any chance a 30mA RCD (Residual Current device)?

 

[g60kg]

"It also has a 30amp circuit breaker thing which does not trip when the fuse is cooking. "

Is this by any chance a 30mA RCD (Residual Current device)?

probably... it has two switches one main black one and another grey one with red and green markers depending on the position of the switch.

I will take pics when I get home tonight and get the info on the shower so you guys can get a better picture.

 

[securespark]

 

[THRIPSTER]

(a) Previous owner has upgraded the shower but not the wiring, MCB and fuse that supply it?

(b) You have upgarded the shower but haven't upgraded the wiring,MCB and fuse that supply it? Therefore looking for advice on what cable size should be and hoping that you will get away with it?

(c) Neither of the above and I am talking horse****. Edited by me to frustrate the murderator.

 

[g60kg]

Very funny analysis Thripster. I have not touched the shower maybe you are right about the shower upgrade without the fuse upgrade.

the shower is a Triton 9.5kw and manual says to use a 45a cartridge fuse. Everything else has been done to specification such as the 30mA RCD and 45amp double isolating switch (pull cord). The only other thing that might be wrong is the cabling, something I know nothing about so please see attached pics and advise if possible
cheers
kg

 

[ColJack]

so what is it that's surprising you? that the shower is "cooking" a 30A fuse when the manual says it needs a 45A???

you need a CU upgrade my friend.. those type are not designed to deliver more than 30A per fuse holder... if they do make a bigger one, it's going to cause some damage if fitted as the busbars and such inside it are not designed to take that current..

 

[reggie perrin]

But it's been OK for the last fourteen years without a problem...

You're just trying to make money out of me.

I'm calling Rogue Traders.

 

[JohnD]

the way it has been installed is not right.

The 45A CU should not have been supplied from the 30A way in the old CU.

A proper job would have been to put the new CU in parallel with the old one, which would not have been significantly more difficult or expensive (although the supply would have had to be isolated). This sugggests it was not installed by a professional nor by a skilled amateur. It needs to be re-done properly. I'm not sure if your cable is of correct size. Earthing and bonding need to be checked as the person doing the installation might not have done it right.

 

[ColJack]

the cable size should be embossed on the cable itself every 12-18 inches..

 

[securespark]

Says who???

I rarely find the cable size embossed on T & E...

I'm confused anyway. John talks of a 45A unit, but the pictures are of a Wylex 30A BS1361 fuse in one board labelled SHOWER & another 1 way CU with RCD incomer with a 50A breaker in it.

If that Wylex feeds the Volex board, then that IS wrong, as J explains. 9.5kW is pushing it for 6mm² T&E, which I think it is. Generally, 8.5kW is considered the maximum for 6mm² T&E, especially given the possibility of it being run under loft insulation, grouping factors, amb temp, etc...

Reggie: What are you on? It "may have been like that for X years", but that doesn't mean it is right, or safe.

 

[JohnD]

John talks of a 45A unit,

my mistake, I meant the one with 50A MCB and RCD. But he says the manual mentions a 45A MCB.

p.s. I think you'll find Reggie was joking