hot tub installation instructions

[James]

So I have a hot tub to install, in this instance, it is not a problem because there is an existing DB that is TT to provide power for electric car charging.
supply to building is PME.

have a look at the electrical installation instructions, they are not the worst in the world but I think they are a little confusing.

if i didn't have the option of coming off a TT board, and wanted to use the existing earthing arrangements, would this comply with the manufacturers instructions?

and yes I know that i could TT the device itself but that would require a rod and a large hammer, too much like hard work!!

would love to hear your thoughts on this one.

 

[loz2754]

According to these instructions, they are pretty much insisting on a TT arrangement. But the reference to Minor Works TT makes no sense, therefore you could argue that the manufacturer's instructions are invalid and use whatever system you deem to be appropriate.

Hot tubs have become a bit of a minefield recently. IET Wiring Matters magazine have just published a very in depth article on the subject, which, to my mind, complicates the subject even further!

 

[James]

You will need to provide one 16 amp dedicated supply, by the way of a Type C breaker at the consumer unit connecting to (using the relevant gauge armored cable) an isolating switch, which can be locked off to carry out work.
These supplies need to be RCD protected and can either be mounted on an adjacent wall or to a post no closer than 2 meters from the Hot Tub
The electrician will also need to supply and fit a suitably sized, 3 core, cable (6 sq mm max) in Armoured (SWA) or Flexible Armoured (SY), which will reach safely from the isolator or switch to the nearest Rear Corner of where you plan your spa to be and have enough length to reach the electrical entry point of your pool, with a minimum of 2 metre extra length to allow it to be passed into the Hot Tub and wired to the control box as shown by the RED line in the diagram below.
The diagram below is an example only. The actual entry point for your Hot Tub is shown, Marked as “Electrical Connection" on the Architectural Drawing on the last page of these instructions 2021 Beam Spa Installation Instructions and Watercare Guide If you intend to bury your cable please ensure it is buried at least 450mm deep, encased in high impact duct of preferably 32mm or 25mm diameter.

Bring the supply up near the cable entry point as shown on the Architectural Drawing on the last page of these instructions. It is important that the duct does NOT come up in a position that will end up underneath the spa as this will cause serious difficulties on the day of installation

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To comply with BS7671 Minor Works Certificate regulations the electrician should also fit an earth Rod to TT Procedure standards

PME is acceptable all the way to the tub but, as advised by NICEIC, 'best practice' is to use PME to the isolator and local area TT only from the isolator to the tub.
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The RCD should be a C type 30 mA ALL FITMENTS AND ISOLATORS MUST CONFORM TO AN ABSOLUTE MINIMUM OF IP55 RATING

last bit between the ***** and the other *****
I understand what it says but it makes no sense!!

PME is acceptable
best practice is PME isolator and TT to the tub
PME is acceptable all the way to the tub.

so manufacturer is saying you can do it either way and comply with there instructions but if you don't TT it, they are going to say well we recommended you did it this way but told you either way was acceptable???