13amp Hot tub supply

[HRM-ELEC]

Hi, I've been asked to install 13amp supply for a hot tub around 30m from the house.

Supply to property TN-C-S

Plan is to run a 4mm 2 core swa from a 16 amp mcb in the CU to a IP66 RCD switched fused spur (Aprox 25m from house)

Use the armour as the earth until it reaches the Rcd spur in which case I will heat shrink swa and then fit stuffing gland to terminate.

Earth rod with 10mm to the RCD spur and TT the rest.

Any advice would be great

 

[Charlie_]

What rating is the hot tub?
I usually do away with fcu option and just keep it all at 16amp..
obviously still have RCD protection

 

[Taylortwocities]

Isolator switch required close to the hot tub.

 

[Toneyz]

How will you terminate the 10mm earth into the FCU?

 

[PEG]

What's this obsession with hot-tubs? ....are they for people who won't have a bath...unless they have a glass of plonk in their hand?

Had three to look at,in last week...one out of action a while...looked like a jumbo bowl of pea soup

 

[buzzlightyear]

Earth rod with 10mm to the RCD spur and TT the rest.

why .

 

[Nigel]

4mm - 13A???

Earth rod - why?

I would fit a socket if the customer is having a hot tub company deliver it as they will only want to see a socket.

 

[Charlie_]

4mm - 13A???

Earth rod - why?

I would fit a socket if the customer is having a hot tub company deliver it as they will only want to see a socket.

I’ve had a few call outs where they have used a standard plug & socket, couldn’t remove the plug as it had melted onto the socket..

One of them shouldn’t have been on a 13a plug, as it was rated at about 3.2 kw.
The hire company had used a commando plug to 13a converter

 

[Pete999]

Hi, I've been asked to install 13amp supply for a hot tub around 30m from the house.

Supply to property TN-C-S

Plan is to run a 4mm 2 core swa from a 16 amp mcb in the CU to a IP66 RCD switched fused spur (Aprox 25m from house)

Use the armour as the earth until it reaches the Rcd spur in which case I will heat shrink swa and then fit stuffing gland to terminate.

Earth rod with 10mm to the RCD spur and TT the rest.

Any advice would be great

Heat shrink the SWA? I take it you mean connect the armour to the Earth terminal in the FCU? Advice use a banjo on the SWA and use some suitably sized wire from there to the terminal, If I read your intentions correctly that is not the way to install this SWA, have you done any calculation for cable sizing. or is this a stab in the dark job. a stuffing gland is not the correct method, well you did ask.

 

[HRM-ELEC]

The reason for heat shrink was to drop the pme earth at the FCU

As in the regs it recommends not to use PME earth.

 

[mhar]

Isolator switch required close to the hot tub.

After having read 702.53, not too close!

 

[HRM-ELEC]

For give me if I'm wrong on the earthing arangement.

I have around 80m of 4mm swa in my garage that needs using up should have stated that in original post.

I'm going to have to ring up the hot tub company as it only say on there website 13amp supply. Could really do with a power spec

 

[Charlie_]

For that length of run you will need 6mm, based on a load towards the maximum 13 amp.
If you really want to use the 4mm then you will need to double up the cores

 

[Welchyboy1]

For these plug in hot tubs, Is there a minimum distance the socket must be from the side of the hot tub, obviously zones apply, is it the same as a bath,

 

[Welchyboy1]

Isolator switch required close to the hot tub.

Is an isolator still required with 13a plug and socket hot tubs?,
obviously with the 32a they would be

 

[Welchyboy1]

For that length of run you will need 6mm, based on a load towards the maximum 13 amp.
If you really want to use the 4mm then you will need to double up the cores

You sure about that? 16amp supply 4mm is about 60meters off the top of my head

I may be wrong

 

[Welchyboy1]

For that length of run you will need 6mm, based on a load towards the maximum 13 amp.
If you really want to use the 4mm then you will need to double up the cores

You sure about that? 16amp supply 4mm is about 60meters off the top of my head

 

[telectrix]

you will probably find out from the tub supplier/manufacturer that it come with an integrated 10mA RCD in the mains lead. i get the VD on 4.0mm to be 4.3V so it's adequate for the job. ( 11 x 13 x 30 )/1000.

 

[HRM-ELEC]

Would you drop the pme earth at socket/isolator and TT the rest or am I over thinking it ?

 

[Midwest]

Would you drop the pme earth at socket/isolator and TT the rest or am I over thinking it ?

I’ve read here before now, that some would do both.

What surface is the hot tub being installed on?

 

[Charlie_]

Going off the top of my head too so not %100 sure..
The length of run is 80m though

 

[HRM-ELEC]

It will be Sat on decking with around 2/3ft surrounding before it turns to grass again

 

[Midwest]

The length of run is 80m though

That’s the length of cable OP has in his garage.

 

[Charlie_]

That’s the length of cable OP has in his garage.

.
Ahhh hahaha okey dokes

 

[Charlie_]

That a long garage

 

[Midwest]

It will be Sat on decking with around 2/3ft surrounding before it turns to grass again

Never done one myself, but it’s a common question raised on here. As said, I read before that some advise with pms supply, to use supply earthing facility AND rod near tub.
Perhaps more learned members can comment on that?

 

[robd]

Read a best practice guide on hot tubs which said TT it so I've done that on the few that I've done since.

 

[HRM-ELEC]

Having come off the phone to a American bloke who could not not me the power raiding except it pulls 12.8 amps when pumps start.

My installation

16amp mcb from CU to a rcd ip enclosure with rcd fitting inside (drop pme at this point)

Pick up new TT earth

To 25amp rotary is lsolator to the hot tub

 

[Deleted member 26818]

Tescos and BM seem to selling a lot of LayZspa hot tubs at the moment.
The Hot tub itself is inflatable, like a large paddling pool.
The pump/heater/bubble maker is a separate unit with quite a long lead which has a 10mA in line RCD.

The pump unit is waterproof, though I have not found an IP rating. The unit has to be next to the tub to connect the pipework and so the controls can be reached.

 

[Charlie_]

Hot tubs
Local isolation
Very drunk people
What could possibly go wrong

 

[remedial]

is the TT earth just cos of the distance from the house? my mate got a jacuzzi hot tub installed a couple of years ago. they insisted on an electrician being on site when it was delivered. but i believe the standard install is just swa from the tub to an isolator switch nearby, and then fed back to the CU with RCD protection.

 

[Deleted member 26818]

Thing with these hot tubs, is you have to use chlorine, continuously heat and circulate the water and clean the filter daily.

 

[Nigel]

So if you need to TT will be based on whether if the PEN drops out is there a risk of a return path, from a fault through your body to true earth.

I have a hot tub and I have a PME but I have not TT'd it. The hot tub is all plastic and there is not extraneous conductive parts or exposed conductive parts anywhere near. The water heater is double insulated.

So if there is a fault there is no metallic parts for the live conductor to touch and bring the hot tub to live potential and the water heater is double insulated and it does not actually come into contact with water. It surrounds the plastic pipe that the water travels through.

So in my case installing an earth rod is a completely pointless exercise.

 

[Deleted member 26818]

The instructions for the LayZspa require the pump unit to be bonded.
Apparently there’s a connection point on the unit for this.

 

[buzzlightyear]

swa from a 16 amp mcb in the CU to a IP66 RCD switched fused spur (Aprox 25m fro

the fused spur will burn out if above the rated birth bath.

 

[Toneyz]

Hi, I've been asked to install 13amp supply for a hot tub around 30m from the house.

Supply to property TN-C-S

Plan is to run a 4mm 2 core swa from a 16 amp mcb in the CU to a IP66 RCD switched fused spur (Aprox 25m from house)

Use the armour as the earth until it reaches the Rcd spur in which case I will heat shrink swa and then fit stuffing gland to terminate.

Earth rod with 10mm to the RCD spur and TT the rest.

Any advice would be great

Thanks for the dumb all I asked was how you would get the 10mm into the spur/FCU an answer would have been sufficient if its advice you want from me then forget it.

 

[buzzlightyear]

Thanks for the dumb all I asked was how you would get the 10mm into the spur/FCU an answer would have been sufficient if its advice you want from me then forget it.

Shirley how would you do that.

 

[Pete999]

Shirley how would you do that.

His name is Ant, Buzz, not Shirley.

 

[buzzlightyear]

His name is Ant, Buzz, not Shirley

ok Shirley ant .

 

[Toneyz]

Shirley how would you do that.

That's what I asked the O.P.