Any Electricians out there?

F

Furtim

Messages
1,753
Name
David
Edit My Images
Yes
I've had a qualified electrician install a 32amp connection in our garden suitable for a hot tub. He's fitted the RCD / external isolator switches etc just fine, my question is over the type of cable he has used.

He's used 2.5mm2 core, where as I think he should have used 6mm2 core. I've questioned him on this, and he say's the supplied 2.5mm2 core is adequate.

The cable run is approx 30m long from the distribution unit.
The hot tub will draw 4KW for the heater, 2 lots of 1.6KW for the pumps and an additional small load for the circulation pump when the other pumps are not in use (0.3KW); so that's 7.5KW at peak load.

I've got all the certs etc, but I'm still not convinced. Anyone here able to put my mind at rest?
 
Not a spark but had dabbled prior to Part P. If it's clipped direct then really 4mm minimum over that distance according to:

http://www.doncastercables.com/technical-help/

From the tlc-direct calculator:
Required Cable Size 4 mm
Voltage Drop 10.0 Volts.
Percentage Drop 4.4%
Current Load 30.4 Amps
Max Cable Load* 37.0 Amps
 
Last edited:
Should add that's normal 6242Y cable, if it's armoured yes @ 6mm.
 
Hi there I have spoken to my son who is a qualified sparky that 4mm or 6mm is the size of cable for 32amp supply.
 
Being a, now retired, electrical engineer surveyor I would question the use of anything less than 6mm cable in your case.
 
As a rule of thumb 6mm for a 32a supply. I'm assuming it's steel wire armoured as you've said its 2 core and using the armour for the earth. Most sparks would run a 3 core nowadays.
 
Thanks everyone armed with your professional opinions I've had a few more conversations with him and he's agreed to return and run a 6mm cable.
 
DavidMartin said:
As a rule of thumb 6mm for a 32a supply. I'm assuming it's steel wire armoured as you've said its 2 core and using the armour for the earth. Most sparks would run a 3 core nowadays.
Click to expand...
It is 3 core, the '2' in my question related to the mm squared, but now I can see why no one uses that.

Thanks again
 
Llamaman said:
View attachment 48781
Click to expand...

Though a certificate was issued it does make wonder if said electrician's status should be confirmed with the body he says he is accredited to/with by name not company. We had electrical work done by a small company and the guy that was authorised to sign off was one of the employees not the owner.

His use of lower rated cable than acceptable and recommended does not inspire confidence.....so is he all he claims to be???
 
Update. It turns out the hot tub can be set to two configurations. The European version defaults to 20 amps and achieves this through load shedding (heating is suspended when both pumps are running). It can be configured to run at full capacity (which is what we have ordered).

The spark asked in the shop and they gave him the defaults and that's what he sized it as.

Anyway he replaced the wire with 6mm. Hot tub now installed and guess what - they've left it in the default 20amp mode (that's how I know it exists!). Waiting for guy to come and switch config.

So perhaps the electrician wasn't from the Wild West after all.
 
You must log in or register to reply here.
Back
Top