6mm swa to 10mm t&e

[mooney3]

Hi,
I am having a hot tub delivered and I want to make a connection in the loft between 6mm swa and 10mm t&e, I intend to run the cables along the rafters so no insulation involved.

The reason for the 10mm t&e is that I had an extension built and had a 50amp breaker installed next to the CU with 10mm t&e put into the loft just in case I ever wanted to have an electric shower installed. I want to use these as the swa isn't long enough to go straight to the CU and I don't have the space in the CU anyway. The 10mm t&e is approx 4m from the intended connection box to the breaker

The hot tub has a 40amp external isolator already set up, with 20m of 6mm swa (just needs connecting to the tub)

I will terminate the swa to a steel box (with lid) fixed to a rafter using a 20mm gland, and earth the swa and t&e to the metal box. The live connections will be made into 100amp connection blocks (spare ones in my toolbox)

My questions are
Is it correct to connect 6mm swa to 10mm t&e
Am I OK to use the 100amp connection blocks

Thanks in advance
Paul

 

[PrenticeBoyofDerry]

You can terminate 6mm SWA to 10mm T&E, but always be aware of the lower current carrying rating when loading.
100A rated connections are fine as the circuit is protected by a 50A breaker. You must provide RCD protection for this appliance though.

 

[mooney3]

Hello PrenticeoyofDerry.
The 50A breaker is protected by a 63A RCD as it is an IP65 shower kit enclosure.

 

[PrenticeBoyofDerry]

Okay, I would recommend that prior to energising the circuit, that the required testing procedures are carried, to prove that the circuit is safe and safety devices are/will operating as expected.

 

[ban-all-sheds]

100A rated connections are fine as the circuit is protected by a 50A breaker.

The hot tub has a 40amp external isolator

 

[mooney3]

Of course, just trying to reduce the cost and putting my inexperienced 3 years of college work in to practice. I appreciate the testing that has to be carried out at the end.

Thanks

 

[PrenticeBoyofDerry]

100A rated connections are fine as the circuit is protected by a 50A breaker.

The hot tub has a 40amp external isolator

Indeed good spot.
To the OP, as the protective device is rated above the isolator, that would need correcting, you must have everything rated equal or above that of the protective device. So in this case I guess that the hot tub has a design current of less than 40A, so for overload protection the 50A device should be changed to a 40A one.

 

[ban-all-sheds]

I am having a hot tub delivered and I want to....

Have you familiarised yourself with Section 702 of the Wiring Regulations?

 

[EFLImpudence]

The 50A breaker is protected by a 63A RCD as it is an IP65 shower kit enclosure.

Not protected by, the 63A is its maximum current rating and it(the RCD) and the cable will be protected by the (now reduced to 40A) MCB.

It is, or must be, a (maximum of) 30mA RCD for the protection of persons, not the equipment.