Isolator Switch Question

[Mitchet]

Hi all, I wonder if you could perhaps offer any help. I'm doing some of the electrical work involved with installing a hot tub

From the CU in the garage, the total cable distance to the tub is about 20m. The tub power consumption is 4.7KW, so by my calcs, that approx 20A with the cable size (using 3 core SWA XLPE) being at least 2.5mm... though I'm using 4.0mm so that (1) I can be on the safe side! (2) If I need to take into account the cable length from the garage CU to the main CU? and (3) I'm also installing an IP56 (when in use) socket near the tub for an iPod dock!

My main question is that I have a 32A isolator switch which is going on the exterior wall of the garage, but I'm just looking for some guidence on installation. The unit has L1,2,3 and T1,2,3 plus a smaller connection which isn't labelled but is still switched... I'm not sure what this is for?

Anyway, should I connect the earth into the isolator switch along with the live and neutral? Or should earth be continuous throughout the isolator (i.e . should earth be switched, or should I connect the earth from the load and supply into a single block)?

I've heard conflicting reports on this... but I've installed an earth rod next to the hot tub. Not sure if that makes any difference to my last question?

Just in case anyone asks me... I'm obviously not an electrician, though I did spend 3 years doing electronic and electrical engineering at college (about 15 years ago!). So I'm more than aware of Part P!

I've advised the guy I'm installing the tub for to get an electrician to check over the work I've done and test it, then get him/her to make the final connection to the CU.

...speaking of which (sorry!), since the tub will take 20A, I would presumably need a 25A MCB... but they don't seem to be widely available? The garage CU already has a 40A 30mA RCD installed.

Apologies for the multiple hidden questions!!

Thanks for your help in advance.

 

[thompsk]

Hi all, I wonder if you could perhaps offer any help. I'm doing some of the electrical work involved with installing a hot tub

From the CU in the garage, the total cable distance to the tub is about 20m. The tub power consumption is 4.7KW, so by my calcs, that approx 20A with the cable size (using 3 core SWA XLPE) being at least 2.5mm... though I'm using 4.0mm so that (1) I can be on the safe side! (2) If I need to take into account the cable length from the garage CU to the main CU? and (3) I'm also installing an IP56 (when in use) socket near the tub for an iPod dock!

My main question is that I have a 32A isolator switch which is going on the exterior wall of the garage, but I'm just looking for some guidence on installation. The unit has L1,2,3 and T1,2,3 plus a smaller connection which isn't labelled but is still switched... I'm not sure what this is for?

Anyway, should I connect the earth into the isolator switch along with the live and neutral? Or should earth be continuous throughout the isolator (i.e . should earth be switched, or should I connect the earth from the load and supply into a single block)?

I've heard conflicting reports on this... but I've installed an earth rod next to the hot tub. Not sure if that makes any difference to my last question?

Just in case anyone asks me... I'm obviously not an electrician, though I did spend 3 years doing electronic and electrical engineering at college (about 15 years ago!). So I'm more than aware of Part P!

I've advised the guy I'm installing the tub for to get an electrician to check over the work I've done and test it, then get him/her to make the final connection to the CU.

...speaking of which (sorry!), since the tub will take 20A, I would presumably need a 25A MCB... but they don't seem to be widely available? The garage CU already has a 40A 30mA RCD installed.

Apologies for the multiple hidden questions!!

Thanks for your help in advance.

Firstly do not switch the Earth connection, they are there for safety and should not be switched.

The extra terminals are probably auxillary terminals, just ignore them. The terminals you will connect into are L1 Brown Live in - L2 Blue Neutral in T1 Brown Live out - T2 Blue Neutral out.

Being as this work is outdoors you must get it checked by a fully qualified electrician who must proivide you with all the relivent testing certificates and it must also be notified to your local council. If you are unsure as to what you are doing LEAVE IT to the pro's to do. Leccy and water is deadly.

 

[FingRinal]

First things first.

How close do you intend to install a socket outlet to the hot tub??

 

[Mitchet]

Thanks 'thompsk' for the quick reply... I will admit, that switching the earth would seem like a very odd thing to do, but it's best to check!

I also totally agree leaving this sort of stuff to those that are qualified... I decided that I wasn't going to do any more electrical work a few years back, especially for other people. Though being modest for a moment, I would say that I'm competent with most electrical installations... though like I said, I'm going to leave the final connection and testing to an electrician.

As for the socket... I wasn't too impressed at the idea of the socket, and I suggested some 'wireless' / LV ways to get music near the tub... but anyway, I'm placing the socket far enough from the tub to be splashed/affected by steam/anyone reach up from the tub and stupidly trying to unplug/plug something in!

 

[FingRinal]

Yes, but how far will the socket be from the hot tub? It is a location containing a bath or shower.

The NICEIC (I believe) treat hot tub installs like swimming pools.

 

[Mitchet]

The socket will be on the outside of the enclosure (the gazebo, not the tub enclosure!), mounted 2m up from the ground. Would you think that is okay?

Yeah, I've also heard that hot tubs are treated in the same way as swimming pools from an electrical perspective.

 

[RF Lighting]

I'm not sure TBH, but it would certainly make sense.

@OP, why did you install an earth rod?

I really do not like the idea of a socket anywhere near the hot tub.

You are allowed an RCD protected socket outlet a MINIMUM of 3 meters away from a bathtub. I'm not too hot on swimming pool regs, but I'll have a quick read through.


I have wired up a few hot tubs which have a built in sound system. It is all apropriatly rated for the environment in which it will be used.

 

[Mitchet]

I'm not convinced about the sockets either. Especially since they only going to be used for an iPod dock. I can think of much safer ways to get music wirelessly to the tub... albeit slightly more expensive.

Plus, you know how it is... iPod dock today, but give someone a socket, and they'll find something to plug into it (like a patio heater!! )

As for the earth rod - The tub has come from a previous installation where the electrician (who installs tubs all the time), used one. So the tub still has the earth tail and clamp attached.

 

[Softus]

Mitchet, in case you weren't aware, section 603 of the wiring regulations prohibits the presence of a socket outlet any closer to the tub than 2.0m. There are further restrictions if the socket outlet is closer than 3.5m.

BTW, you can disregard what the NICEIC thinks of your installation - it isn't the approval authority in your situation.

 

[FingRinal]

Softus, why the downer on the NICEIC? Wouldn't they take you?

Also 603 refers to SAUNAS!!!

It is a matter for the NICEIC if they choose to insist on higher standards than those found in BS7671.

I, personally, disagree that a hot tub is a swimming pool. But their position is indicative of their concerns regarding hot tub installations (pre-Part P when it was just Approved Contractors).

Should I state that the NICEIC is an authority on a particular issue, I will make it clear that it is so. Panyatna?

 

[Softus]

Softus, why the downer on the NICEIC?

No downer at all. It (not they) is irrelevant.

Also 603 refers to SAUNAS

Quite so - finger trouble thanks for pointing out the error. I meant 602. Apologies to anyone who was thrown by that.

It is a matter for the NICEIC if they choose to insist on higher standards than those found in BS7671.

I couldn't agree more - it's a matter for the NICEIC.

I, personally, disagree that a hot tub is a swimming pool.

Section 602-01-01 covers not only swimming pools, but also paddling pools.

Should I state that the NICEIC is an authority on a particular issue, I will make it clear that it is so. Panyatna?

You're free to state whatever you like, but the NICEIC is a club, not an approval authority on any domestic wiring issue.

 

[ricicle]

the NICEIC is a club, not an approval authority on any domestic wiring issue.

Absolutely agree 100% - and the sooner the brainwashing stops the better IMO

 

[RF Lighting]

I worked for NICEIC ACs for 9 years.

I'm free!!!

(ECA now)

 

[FingRinal]

As it caused confusion for some reason, I shall repeat..

Should I state that the NICEIC is an authority on a particular issue, I will make it clear that it is so. Panyatna?

Does that make it clear?

And since when is a paddling pool a hot tub? Or a hot tub a paddling pool?

Or are we back to guessing and nit-picking again?

 

[Mitchet]

Just want to say thanks for your input on this.

I'm not happy with the socket installation being so close... so I'll tell them to go down the route of getting a wireless speaker system instead.

Any ideas on the earth rod requirement though?