Shower keeps tripping fuse.

[pinkkitten]

Hi,
I was wondering if anyone can advise. We have just change our shower from 8.5kw to 9.5kw. When we bought it we were told that we could easily go from 8.5 to 9.5kw without having to change anything. Since having the new shower installed after about 10 mins of use it trips the shower fuse at the main box

I have been reading through previous posts and by looks of it we dont have a big enough fuse to cope with the 9.5kw as we were told, the fuse we have in at the moment is 32amp

As far as I can tell I now need to change the fuse to a 40amp or 45amp, not sure what one would be best? also is it as simple as just buying a new fuse and changing them over? sorry for the naive question but I have been told to just go buy one and im not interlay sure if this is possible?

thank you for your help

 

[luminaire]

When you say fuse I presume you mean MCB (miniature circuit breaker). Would it be possible to send pic of your Consumer Unit so we can see? Is it RCD protected for instance?
In any event you will need 45A MCB.

It would be better to let a local electrician have a look at it in case your cable also needs upgrading. Do you know what size cable it is?

 

[pinkkitten]

Thank you for fast reply

Yes sorry its the MCB - I will take a pic of it tonight
Im sorry im not sure what size the cable is either, we thought it was possible 10mm but not 100% sure... I assume that if we were to take the existing fuse out then we would see the size of the cable.

A friend of the family (hes not a qualified electrician) has told us it is possible to change the fuse if i just go and buy one, but i have been having trouble finding one so far and i hoped to get a second opinion first

Thank you.

 

[Adam_151]

Cable size... easy enough to compare if you have some offcuts of 6 and 10 laying around!, if not, see if the CPC (earth wire) is stranded or solid conductor


moving on...

You need to be aware of a number of things:

1) You cannot just change the circuit breaker for one of a larger rating without verifying that the cabling is upto the job!

2) You might have trouble finding a CB depending on the make and vintage of the board, you should not mix and match ranges and makes, and sometimes it can be difficult to find the right part

3) There are some boards out there (wylex standards with 60A main isos) that cannot take anything bigger than 32A

4) 32A was too small for the 8.5kw as well, probably didn't trip, but its poor design 8500/240 = 35.4A

5) Uprating the CB is notiable under the building regulations

6) You should ensure all earthing, equipotenial bonding, and RCDs are as they should be

 

[pinkkitten]

Thank you for your help.

We didnt know we werent able to mix them, which is a bit of a nightmare as i cant seem to find any of the make we already have - its a Memera21 MEM M6 Type1 32 IQEB that is there at the moment.

Thank you

 

[pinkkitten]

Pictures of the unit as requested. Hope you can see them ok? the one i need to replace is the far left fuse (of the middle cluster)

i have had closer look at it also and it seems like all cables comin out of the unit look like 10mm (fat grey ones )

thank you. View media item 2938 View media item 2937

 

[bongos]

Is the shower currently on the RCD side of the consumer unit? It should be and if it isn't then you may find that you don't have any spare room on the board to put it on that side.

The consumer unit looks quite old. I wouldn't know if they still make those specific MCB's although the fact that it already has a 45A one in there might make it possible to source one from somewhere.

 

[pinkkitten]

Sorry im not sure what the differences would be for RCD and for the main board

 

[industryspark]

pinkitten, from reading your posts i would recommend you get a spark in to sort it out.

to change the mcb you will need to enter the consumer unit - not a place you want to mess about in if your not sure what you are doing. also you dont have test equipment so how can you test that zs of the circuit is complient and that rcd's are performing to spec?

 

[pompeygit]

Whoever installed that had a lot of pride.........bet its a birdsnest inside

 

[ban-all-sheds]

5) Uprating the CB is notiable under the building regulations

pinkkitten

Joined: 16 Jul 2008
Posts: 5
Location: Aberdeen,
United Kingdom

 

[sm1thson]

what is the 45A breaker which is already in there feeding? and what is the load (kw's) of this?

 

[ban-all-sheds]

i have had closer look at it also and it seems like all cables comin out of the unit look like 10mm

"10mm" means that the cross-sectional area of the live and neutral conductors is 10mm², not the width or thickness of the whole cable.

what is the 45A breaker which is already in there feeding? and what is the load (kw's) of this?

I think it says "Cooker"

 

[sm1thson]

what is the 45A breaker which is already in there feeding? and what is the load (kw's) of this?

I think it says "Cooker"

can the OP confirm that it is just the cooker, and clarify that this is the oven and electric hobs, or if it is the oven and gas hobs etc (also turn it off and see if anything else goes off) and then tell us the rating (kW) of the cooker (and anything else found to be on the circuit). The rating will be on a plate on the back of it which probably isnt most helpful right now but if you google the make and model you should be able to find it (easier than pulling the cooker out) ,or look in the instructions if you still have them.

(the reason i ask is if that circuit doesnt need 45A then you MAY be able to swap them)