Hot tubs and PME or TT

[Jako13!]

Hi guys I have a question on installing an outside supply to a spa at home. I have a few questions regarding this one is the consumer unit has no spare ways have checked maximum demand and all seems okay for an additional 32 amp load. My plan was to get a garage style CU and take out out of the 6 amp lighting circuit breakers at the main board and replace with a 40amp breaker to feed the new CU containing the lighting circuit and swim spa circuits. I’m then planning on running a 6mm swa outside to a rotary isolator.

first question is does the new CU require surge protection? (I know this will have to be signed off by someone who is registered as I’m not registered)

Does the lighting circuit require an installation certificate as well? I’m presuming it will as I’m installing it in a new board.

and lastly (I know there is many debates about this) but what are your guys thoughts on TNCS supplies and earth electrodes? I’ve been told by the manufacturer they’ve never heard of any electrician ask about using an earth electrode?

thank you for your replies in advance

 

[westward10]

The EIC will cover the new board and consequently the lighting circuits connected from it although the EIC doesn't strictly encompass the circuits as such. The EIC covers the new board and new circuit but you need to test the existing circuits and enter the results on the schedule.

 

[Jako13!]

So the circuit feeding the new board and the new CU circuits will all need testing. What is the regs on if it requires surge protection? I was always under the impression that every new install needs to be up to the latest regs so if I was adding an additional socket that’s not RCD protected I’d have to fit the whole circuit on an RCD to comply.

 

[littlespark]

Depends if the tub is going to be used in a lightning storm....

No circuit "requires" surge protection. You may fit one UNLESS the customer asks not to have one. So its not mandatory.

 

[timhoward]

Have a read of this...

Client refusing spd - in - UK Electrical Forum

, Client refusing spd, UK Electrical Forum, ElectriciansForums.net Est.2006 | Free Electrical Advice Forum and page_number.

www.electriciansforums.net

... the punchline is you don't need an SPD in "single dwelling units where the total value of the installation and equipment therein does not justify such protection".
I'd also comment that this is a sub-main, surges on the incoming supply have already done their damage, and direct lightning strikes on the sub-main's cable are probably unlikely.