Mcb for storage heaters

[SoulkillaH]

Hi !

I had 2 storage heaters fitted on the same circuit, protected by a 20 amp Mcb.

the wire is 2.5.

The Mcb was tripping at every few minutes.

I changed the 2 switched spurs with 2 new ones and the 20 amp mcb with a 32 amp.

the heaters are 2x 2.4kw.

It was a good idea to change the 20 amp with 32 amp mcb?

Thanks!

 

[danny7299]

no!!! ... 2.5 cable will only do about 24 amps, so putting a 32 braker on it could be a fire issue.

have you tried to find out what is the fault...i.e turn off both heaters and try the mcb , if it goes up and stays up there is a fault with the storage heaters. turn one on at a time and if it trips you found out which one is the faulty one.

if you turn off both heaters and the MCB will not stay up there is probably a problem with the wiring going to the heaters from the Consumer unit.

 

[Evans Electric]

Those two heaters are right on the limit for a 20 A MCB, so four options:-

1. Install a 2nd circuit.

2. Fit a 25A MCB.

3. Disconnect one element in one of the heaters.

4. Rewire in 4mm and keep 32 A MCB .

 

[m4tty]

^^^^^ what he says spot on ^^^^^^^^

Id change the breaker back to the 20A as it should be Ib<In<Iz and what youve done breaks many rules/regs mate.

You can only put 2.5mm cable on a 32A breaker when its a ring (with 2 legs) a radial should be on a 20A max for 2.5mm cable.

Cheers

 

[paul b b]

i would put a new circuit in for the second heater.

as evans says, each heater wants about 10A. so this is the most likely cause, but may also be a L-E short somwhere, you may wat to do a IR test to confirm cable is ok.