Run for a Hot Tub

[SparkySue]

Hi Folks,

I realise that you have replied to previous threads on this subject (and I seem to have read most of them !) but I would still appreciate some advice.

I have been asked to provide a circuit for a 40A hot tub in a small back patio. The patio is reached from a bedroom on the first floor. The consumer unit is also on the first floor but due to lack of loft I will have to take the cable out to a private alley at approx. 3m high and run along to patio.

Due to the 40A draw and different install methods possible I have gone for 10mm2.

Now, can I run T&E clipped direct along the alley wall and then take the T&E into metal flexi conduit to the hot tub or would some other approach be better?

Cheers,

SparkySue

Update - I have just been looking at Prysmian's web site and the pdf I was looking at suggests that 4mm2 two core SWA would do the job but Big Red Book (table 4D4A) says 6mm2 - do we have a scratchy head smiley?

Link for Prysmian doc - http://www.prysmian.co.uk/export/sites/prysmian-enGB/attach/pdf/BS5467_07_09.pdf

 

[SparkySue]

Hi Folks,

I realise that you have replied to previous threads on this subject (and I seem to have read most of them !) but I would still appreciate some advice.

I have been asked to provide a circuit for a 40A hot tub in a small back patio. The patio is reached from a bedroom on the first floor. The consumer unit is also on the first floor but due to lack of loft I will have to take the cable out to a private alley at approx. 3m high and run along to patio.

Due to the 40A draw and different install methods possible I have gone for 10mm2.

Now, can I run T&E clipped direct along the alley wall and then take the T&E into metal flexi conduit to the hot tub or would some other approach be better?

Cheers,

SparkySue

Update - I have just been looking at Prysmian's web site and the pdf I was looking at suggests that 4mm2 two core SWA would do the job but Big Red Book (table 4D4A) says 6mm2 - do we have a scratchy head smiley?

Link for Prysmian doc - http://www.prysmian.co.uk/export/sites/prysmian-enGB/attach/pdf/BS5467_07_09.pdf

 

[Doc Hudson]

Hello Sue, How long is the the total run from CU to tub? How long is the run in flex conduit?

Doc H.

 

[Doc Hudson]

Hello Sue, How long is the the total run from CU to tub? How long is the run in flex conduit?

Doc H.

 

[SparkySue]

Would you belive 26m - 15m in alleyway 11m to tub.

Thanks

 

[SparkySue]

Would you belive 26m - 15m in alleyway 11m to tub.

Thanks

 

[sparkytim]

Hi

OSG Table 7.1 gives 6mm Clipped direct ok for 40 A rcbo or MCB with RCD protection up to 40 Mtrs.

I would think again about the Metal flexy conduit.

BRB Pg 170 Section 702 has all the requirements for Hot tubs as they are classed as a swimming pool.

 

[sparkytim]

Hi

OSG Table 7.1 gives 6mm Clipped direct ok for 40 A rcbo or MCB with RCD protection up to 40 Mtrs.

I would think again about the Metal flexy conduit.

BRB Pg 170 Section 702 has all the requirements for Hot tubs as they are classed as a swimming pool.

 

[Larnacaman]

Sparky Sue,

Prysmian vs Big red book....

I think You were looking at Prysmian's ''XLPE'' insulated armoured cable, so higher current ratings because of it's 90c temp rating, as opposed to PVC insulated rating of 70c. .....

Nothing wrong by the way, of using manufacturers cable ratings as opposed to the Reg's ratings. The Reg's always lean on, or towards the safe side in such areas. We ALWAYS use manufacturers cable rating data on all the major projects i've worked on.....

 

[Larnacaman]

Sparky Sue,

Prysmian vs Big red book....

I think You were looking at Prysmian's ''XLPE'' insulated armoured cable, so higher current ratings because of it's 90c temp rating, as opposed to PVC insulated rating of 70c. .....

Nothing wrong by the way, of using manufacturers cable ratings as opposed to the Reg's ratings. The Reg's always lean on, or towards the safe side in such areas. We ALWAYS use manufacturers cable rating data on all the major projects i've worked on.....

 

[Sidewinder]

However, remember that IF you are going to run your cable at 90 deg then the "things" it's connected to must be comparably rated also for compliance.

XLPE is listed in the regs book, it is under thermosetting insulated cables where as pvc is thermoplastic insulation.

 

[Sidewinder]

However, remember that IF you are going to run your cable at 90 deg then the "things" it's connected to must be comparably rated also for compliance.

XLPE is listed in the regs book, it is under thermosetting insulated cables where as pvc is thermoplastic insulation.

 

[Larnacaman]

I suspect that this was just a reference mistake by the OP. She was probably looking for Prysmian's standard PVC armoured cable ratings.... There is no call for an XLPE insulated cable, in the installation she has so far described

 

[Larnacaman]

I suspect that this was just a reference mistake by the OP. She was probably looking for Prysmian's standard PVC armoured cable ratings.... There is no call for an XLPE insulated cable, in the installation she has so far described

 

[Sidewinder]

True, mind you may find that a lot of the cables now supplied from stock in the UK are XLPE!

My wholesaler of choice rarely stocks pvc these days.

 

[Sidewinder]

True, mind you may find that a lot of the cables now supplied from stock in the UK are XLPE!

My wholesaler of choice rarely stocks pvc these days.

 

[Badger]

why not run 3 core armoured 6mm or 10mm depending on cable calcs?

 

[Badger]

why not run 3 core armoured 6mm or 10mm depending on cable calcs?

 

[sellers]

you can use 4mm xlpe, just!

I'd install a 6mm, about 50p per meter more, so

 

[sellers]

you can use 4mm xlpe, just!

I'd install a 6mm, about 50p per meter more, so