Whirlpool bath isolation

[RegPrescott]

Just looking for a bit of advice please

I've just fitted a whirlpool bath and after reading all the posts here about wiring here's what I've done:-

Pump wired to unswitched FCU which is in turn wired to an RCBO.

I then intended to wire this to an isolator and then spur this off the upstairs RCD protected 32A ring. Is the isolator necessary?

Cheers

Mike.

 

[securespark]

Not sure I follow, Reg/Mike/Whatever your name is!!

You've got an unswitched FCU feeding the pump, fed via an RCBO at the CU, yes?

It's the isolator, upstairs RCD ring bit I don't understand.

You need a DP isolator somewhere for maintenance purposes.

But, your RCBO will provide you with earth fault protection, so why do you want to feed from the upstairs RCD ring?

Just re-read your post. I guess the RCBO is stand-alone and not part of the CU.

No need to connect to RCD protected circuit if you have RCBO already, but do need DP switch for disconnection puposes.

Where have you mounted the RCBO?

It will need to be accessible, as will the FCU in case of a trip.

I would either take a feed from the rcd ring to the pump via an accessible DP switched FCU, or take a new feed from the CU via the RCBO (also providing a Switched FCU), but not to mix the two.

 

[RegPrescott]

FYI it's Mike. Reg Prescott was the DIY "expert" on the Kenny Everett television show. Remember it?


The pump goes to an unswitched fused spur under the bath, this then goes in to the RCBO also under the bath. I've then connected the RCBO to an MK three lockable isolator outside the bathroom and this will then go straight to the CU then to a 16A MCB.

Thanks for your help.

Mike / Reg

 

[Big_Spark]

FYI it's Mike. Reg Prescott was the DIY "expert" on the Kenny Everett television show. Remember it?


The pump goes to an unswitched fused spur under the bath, this then goes in to the RCBO also under the bath. I've then connected the RCBO to an MK three lockable isolator outside the bathroom and this will then go straight to the CU then to a 16A MCB.

Is it just me or does that seem way over the top for circuit protection!

 

[RegPrescott]

You're not kidding. Don't forget the equipotental bonding of the motor with 6mm earth back to the CU .

It's not too different to the recent discussion on protecting the bathroom fan circuit though is it?

Fuse for insurance purposes as the instructions state it needs to be fused, RCBO protection for my general well being and lockable isolation (this is downstairs) for maintenance.

 

[RegPrescott]

Hmmm, Numb nuts, could you be more specific when helping out please?
Perhaps I didn't metion that it was only useful advice that was much appreciated.

I'm guessing that you think that the 16A MCB is a little heavy.

Maybe but wouldn't the 13A that the motor draws when it starts up as stated in the installation instructions cause anything else to trip?

 

[RegPrescott]

FWL I think that I'd rather hear your advice here.

I've just seen Grade1Sparks 3 "posts" and don't think he shouldn't even be allowed to have sharp things.

 

[ban-all-sheds]

Don't worry - his parents will be home soon and they'll take him away from the computer....

 

[Big_Spark]

Mike, I wouldn't worry about Grade 1, he's being daft.

Regarding your proposed installation.

Under the whirlpool bath you should mount a waterproof 20A double pole Isolator adjacent ot the lotor for local isolation. (This is optional and not required by the Regs)

Outside of your bathroom you should locate a double pole Isolator, this does not need to be fused.

Then this is fed via a 10A 30mA RCBO mounted straight into the consumer unit.

An alternative would be to replace the double pole Isolator outside your bathroom for a RCD Connection unit and feed this via your upstairs ring.

Incidently, your upstairs ring does not need to be RCBO protected.

Have a look at this...makes it clearer:

 

[il78]

Agreed with FWL, but I would loose the 20A IP rated isolator, unnecessary cost.........

 

[Big_Spark]

Agreed with FWL, but I would loose the 20A IP rated isolator, unnecessary cost.........

Ian, to comply with the Regs he needs it, the RCD connection unit is outside the room and cannot be locked off, therefore he needs to locally isolate.

 

[il78]

It has its own MCB or RCBO at the board and isolation just outside the bathroom.......

example.

Do you install two fan isolators to an extractor within a bathroom.....one outside the bathroom and the other just above the fan.......ETC

As said in another post....in a commercial or industrial installation I would agree, but then the MCB should be locked off any-hoos......

I aint being picky.........well not much......only an ickle bit

 

[securespark]

Looks like I missed some "interesting" posts while on the loo...

spot of tummy trouble.....

 

[Big_Spark]

I aint being picky.........well not much......only an ickle bit

C U Next Tuesday..hehehe

Picky my arse..

Seriosuly though, I have questioned this point with the IEE and the NICEIC, and both say even in a domestic, the isolator should be within visiual site when dealing with fixed equipment.. I understand your point, but Regs is Regs, hence

This needs resolution.

 

[ban-all-sheds]

hence

I'm surprised that you give advice to DIY-ers if you feel that way about them.

"DIY can be both challenging and rewarding - this is where DIYnot.com aims to help."

Are you sure that your presence here is compatible with the above?