Ray wrote:

Do me a favour, electricity is not exactly rocket science - I simply want to
know what side of the CU it goes.

No offence intended, but the second half of your question does not
really enhance the first assertion.

The answer is: "The only one place it could go". You already have (at
least) one isolator before the CU (i.e. its main RCD). Probably another
at the head end of the submain that feeds the CU.

If all you want to do is isolate the hot tub then the isolator must be
between the MCB/fuse that supplies the circuit, and the appliance in
question (and you can't use the MCB for isolation since that is only a
single pole device).

--
Cheers,

John.

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