Shower 8.5 on a 40mcb is it dangerous

[chrismoy1]

Hi guys

My tenant just had an electrician in to connect her cooker and has told her that the shower is dangerous and not to use it because it has a 40 mcb in the consumer unit and it should be a 32.
The cable is 6mm and the shower is 8.5kw.

Can you advise me please
Thank you in anticipation

 

[Welchyboy1]

What a tw*t!

That drives me mad!

 

[snowhead]

Rewinding to the beginning;

The tenant has just had a new cooker (delivered and ?) connected by an "Electrician".
Would this be from Currys or similar?

 

[snowhead]

Duplicate post

 

[telectrix]

apart from all the good advice given so far, as long as the 6.0mm is installed as ref. method C, i.e. it can safely carry 47A, ( Ib<Iz ) then aas the shower is a fixed load, overcurrent protection is not required so a 50A MCB could be installed. 433.3.1 (ii). (BYB 17th).

 

[Deleted account]

So you are sure it is not dangerous because I think my tenant will still want it changed to a 32 because an electrician has told it is dangerous and must not use the shower.

Regards Chris

Without actually visiting the site for an inspection I cannot commit to a definate answer as to whether your installation is dangerous, however
Having a 32A or a40A mcb on an 8.5kw shower is quite common and I would not be concerned either way.
Obviously 40A Mcb is the preferred breaker.

 

[Deleted account]

What a tw*t!

That drives me mad!

I presume the tw*t you are refering to is the original spark who rediculiusly condemned the shower. If so i concur.

 

[dinger809]

Doing some calculations, I don’t agree with your tenants electrician. A 6mm cable, clipped direct will be absolutely fine on a 40amp mcb. The only issue is if the shower circuit is not on an RCD. Providing the run isn't miles and miles.
Putting a 32amp mcb in the circuit will just cause annoying tripping as the 8.5 kw shower will draw around 36amps.
Sounds like the electrician needs to look at the books a bit

 

[Marcus Vaughan]

Doing some calculations, I don’t agree with your tenants electrician. A 6mm cable, clipped direct will be absolutely fine on a 40amp mcb. The only issue is if the shower circuit is not on an RCD. Providing the run isn't miles and miles.
Putting a 32amp mcb in the circuit will just cause annoying tripping as the 8.5 kw shower will draw around 36amps.

Agree it does not need changing, and probably better not to. Not so sure 36 amps would cause the overload part of the breaker to nuisance trip though, looking at the curve for it.

That would be one seriously long shower!

 

[ChrisElectrical88]

apart from all the good advice given so far, as long as the 6.0mm is installed as ref. method C, i.e. it can safely carry 47A, ( Ib<Iz ) then aas the shower is a fixed load, overcurrent protection is not required so a 50A MCB could be installed. 433.3.1 (ii). (BYB 17th).

I mean, going off this even if its in trunking on its own, then it will be alright on a 40A.

 

[dinger809]

Agree it does not need changing, and probably better not to. Not so sure 36 amps would cause the overload part of the breaker to nuisance trip though, looking at the curve for it.

That would be one seriously long shower!

I should have put “could” not “will” cause nuisancebtripping

 

[static zap]

.....

● 8kW - 40amp
● 8.5kW - 40amp
....

I think local supply voltage may be varying a bit between 200/234.4 ave= 214.3 V

 

[Diver233]

Ask her to get her electrician to put it in writing also quoting BS as well as his or her part P approval body.
Then armed with the said information ring the help desk of the said body (they all have a help desk), quote their number etc and speak to them they will give you 100% the answer. Ensure your tennant tells sparky what you are doing. If he is fully approved and he’s correct he will not hesitate in supplying the information.

 

[MG201]

One things for sure they should be greatful they have got a landlord that cares, the fact you are investigating there concerns rather than just saying hey it works what u complaining about shows you care not to mention new cooker

 

[chrismoy1]

Ask her to get her electrician to put it in writing also quoting BS as well as his or her part P approval body.
Then armed with the said information ring the help desk of the said body (they all have a help desk), quote their number etc and speak to them they will give you 100% the answer. Ensure your tennant tells sparky what you are doing. If he is fully approved and he’s correct he will not hesitate in supplying the information.

Thank you Tom for the advice seems like plan.

Regards Chris

 

[chrismoy1]

One things for sure they should be greatful they have got a landlord that cares, the fact you are investigating there concerns rather than just saying hey it works what u complaining about shows you care not to mention new cooker

Thank you for your comments, I just want my tenant to have a safe home they can enjoy after all the do pay the rent.

Regards Chris