Please put my mind at rest

[Hottub]

hi guys I have had an electrician come and put some wiring in ready for a hot tub delivery.

I passed on a electrical document sent to me by the hot tub company which had 6mm on it.

He has run a armoured 2.5mm 3 core cable from the main board and a dedicated 32amp mcb to an external rotary switch ( about 3 metres away ) also 32amp. From the switch he has run the same 2.5m 3 core around to where the hot tub will be ready to be connected ( no more than 4m away ).

He says its more than enough but as I've seen 6mm on the wiring diagram I'm worried.

So shall I stop worrying? Or demand he use 6mm? Or find a different sparky?

Thank you for your time.

 

[Hottub]

Lol cheers for all your help. I will get him back and he can sort it out properly. At least I know my worry was valid.

 

[telectrix]

Not forgetting length of run and ambient temp/insulation etc 'en route' Tel.

there you go complicating the issue. always the negative waves, moriarty, always the negative waves.

 

[Hottub]

Lol cheers for all your help. I will get him back and he can sort it out properly. At least I know my worry was valid.

 

[buzzlightyear]

a lot likes would be nice.

 

[telectrix]

ok i gave you one.

 

[Dave OCD]

Did you indeed ?!

 

[westward10]

I gave him one as well.

 

[NDG Elecs]

Get the, cough, splutter, spark back to change the heating element for a less powerful one and have a warm tub instead! Saves on your leccy bill that way!!
Seriously though, it is a poor show that they fitted 2.5mm if they knew the rating of the hot tub first.

 

[Octopus]

Firstly, I recall 2.5mm swa has a higher rating than 27 amps.

Has said spark been paid? Has he provided you with an electrical installation certificate? A commitment to notify under part P?

 

[David M]

I gave him one as well.

Well if you lot are giving him one I'm going to

 

[Deleted member 9648]

2.5mm thermosetting SWA has a current rating of around 36a clipped direct from memory...I don't have the BYB to hand. So a 32a OCPD device may be acceptable depending on installation method. The problem may be volt drop or 90 degree terminations, depending on the actual load being drawn, and manufacturers instruction. I think you are all jumping the gun somewhat stating this is wrong without all the info. BTW I've added a disagree to post #3 because it's misleading, there are instances where a 2.5mm conductor will be protected by a 32a OCPD. That said in practice I'd never use a 2.5mm based on the info given either. I don't think any of us would install a 2.5mm in this situation.

 

[Deleted member 9648]

I'd also add that it seems unlikely that the actual load will be over 30a given that the OP has indicated a 3kw heater, I cant see a filter pump adding that much, where's the rest coming from?

 

[PEG]

The M.I should also contain details of a suitable OCPD,which if the cable size is 6mm,would be euro-ish. Most older units came with American wire sizing and protection device information.

There are some variables,and lee-way,in the OP's set-up,but would require more specification,and maybe assessment of current during use.....but it hasn't landed yet,has it....

 

[David M]

I'd also add that it seems unlikely that the actual load will be over 30a given that the OP has indicated a 3kw heater, I cant see a filter pump adding that much, where's the rest coming from?

I agree, I can't remember the details but a while back I installed a piece of kit that had an operating rating of 2.7kw yet the manufacturers instructions "recommend" a 6mm supply cable. But it did say something along the lines of " This machine should be installed by a qualified electrician and in accordance with the wiring regulations"
Without all the relevant information its difficult to make a proper judgement call.

 

[andyb]

The MIs are there as a guide, how can they specify the csa of a supply cable when they have absolutely have no idea of the installation. I suspect they say 6mm because that's what would be needed if run in T&E in insulation. Suppose the hot tub was 200m away, would 6mm be acceptable then?
It's up to the electrician to design the installation.