Hi,
I am thinking about installing a hot tub in the garden and I have a few questions.
The hot tub in question apparently requires a 32A RCD. It has a 5.5kw heater and a number of other items / pumps which I am sure contribute to the majority of the 32A load - but i suspect it does not draw the full 32A and certainly not all the time as not everything will generally be on at the same time.
Q1 - What size of SWA cable do I need ?. The run is about 42m long - but may end up being a little more. The cable would run up and down the outside of the house and through the loft space - followed by a few meters buried in the ground. I think I might be on the verge of 6mm2 cable and 10mm2 as I think the breakpoint is quite close. I presume I need 3 core cable.
Q2 - The hot tub is wired by means of connecting to a small control panel - outside that panel there is earth bonding lug. Do I need to bond the tub to earth using that lug? I can't think why as the tub will be sunk into a deck and the only open access would be the acrylic shell and stainless steel jets - but they are probably fed with plastic pipes - so where is the risk?
Q3 - If I need to earth bond the tub - how do I do it - what do I bond it too? - given the earth cable (as part of my 3 core cable) has just been terminated internally in the control panel? Do I need to provide a separate earth spike and bond the tub to that?
Q4 - I plan to run the SWA cable to a weatherproof isolator switch about 2m from the tub. Can you recommend a good switch for that? and I presume its best to go for non metallic switch to remove any earth requirements there as well?
Q5 - Do I have to use SWA cable all the way to the tub - or can I switch to other cable from the isolator switch onwards? It only needs to go below ground leading up to the switch.
Thanks for your help...
Maurice
I am thinking about installing a hot tub in the garden and I have a few questions.
The hot tub in question apparently requires a 32A RCD. It has a 5.5kw heater and a number of other items / pumps which I am sure contribute to the majority of the 32A load - but i suspect it does not draw the full 32A and certainly not all the time as not everything will generally be on at the same time.
Q1 - What size of SWA cable do I need ?. The run is about 42m long - but may end up being a little more. The cable would run up and down the outside of the house and through the loft space - followed by a few meters buried in the ground. I think I might be on the verge of 6mm2 cable and 10mm2 as I think the breakpoint is quite close. I presume I need 3 core cable.
Q2 - The hot tub is wired by means of connecting to a small control panel - outside that panel there is earth bonding lug. Do I need to bond the tub to earth using that lug? I can't think why as the tub will be sunk into a deck and the only open access would be the acrylic shell and stainless steel jets - but they are probably fed with plastic pipes - so where is the risk?
Q3 - If I need to earth bond the tub - how do I do it - what do I bond it too? - given the earth cable (as part of my 3 core cable) has just been terminated internally in the control panel? Do I need to provide a separate earth spike and bond the tub to that?
Q4 - I plan to run the SWA cable to a weatherproof isolator switch about 2m from the tub. Can you recommend a good switch for that? and I presume its best to go for non metallic switch to remove any earth requirements there as well?
Q5 - Do I have to use SWA cable all the way to the tub - or can I switch to other cable from the isolator switch onwards? It only needs to go below ground leading up to the switch.
Thanks for your help...
Maurice