Hot tub for disabled adult - queries on zoning and ratings.

[agouldm9590]

I am being asked too install a local fuseboard within an outbuilding containing a hot tub, the proposed location for the fuseboard is about 1.4 metres from the edge of the hot tub and about 2 metres off the ground. Does this need any sort of enclosure surrounding it or is IPx4 sufficient enough, also with regards too general lighting does it need too be low voltage? Am I right in applying the special location as a swimming pool OR other basin. Please get me back too me with your thoughts! Thanks!

 

[MarkieSparkie]

Providing your hot tub is freestanding ( i.e. not constructed below ground level like a swimming pool) it can be treated as a normal bath tub under BS7671:2008, Amt 1, Section 701. Your proposed location for 'fuseboard' whilst no ideal, would be outside the zones so the general BS7671 regulations effecting environmental conditions and IP ratings apply. 30mA RCD additional protection is required for all low voltage circuits within the location 701.411.3.3. If your lighting is located outside the zones (i.e. >2.25m from finished floor level) the normal low voltage supply can be used. You will also need to consider the route, installation method and possible mechanical protection (or additional protection) of your sub-main to the 'fuseboard'. Consideration of your disabled person (particularly if wheelchair bound or infirm) should be given to the access to the tub, the height and location of all accessories, including the 'fuseboard' which at 2m from the finished floor maybe otherwise inaccessible. Guidance is given in Part M of the building regulations where it is suggested that all accessories and controls are located between 0.45 - 1.2m from the finished floor level.

 

[agouldm9590]

Thats been a great help, erased any uncertainty now as this is a new location for myself, the problem I have is that the owner has pulled in all cables etc himself so I am trying too work with what I have, thanks again, top man!

 

[Engineer54]

If the customer has installed all the cabling for this outhouse, then you will need to check if this is fed from a PME installation?? If it is a PME supply then you must have a 10mm bonding conductor back to the main installations MET, connecting to any metallic services such as the water supply pipe, supplying this hot tub installation...

 

[agouldm9590]

If the customer has installed all the cabling for this outhouse, then you will need to check if this is fed from a PME installation?? If it is a PME supply then you must have a 10mm bonding conductor back to the main installations MET, connecting to any metallic services such as the water supply pipe, supplying this hot tub installation...

The idea is that the 6mm SWA the customer has pulled in is be connected too the original consumer unit, tagging down the sheath and 3rd core being used as a spare earth too that end of the installation, so thus the SWA itself is protected by the rcd that end, then at the other end is too install a 'Garage RCD Board' and supply it using two remaining cores from the 6mm SWA, from this I plan too install a spike into the ground and run a 16mm from the spike too the 'Garage Board', I am pretty sure that the hot tub doesnt have any sort of cold water supply coming into it, its purely filled up via a hose, therefore a Water Bond will not be necessary. What are your thoughts? Thanks.

 

[Engineer54]

Is it a PME or TN-S supply into the main supply?? And if TN-S, why are you dropping that earth in favour of a TT earth?? Come to that, why are you dropping the PME/TNC-S earth in favour of a TT earth, ....this installation is in essence, going to be no different than the bathroom in the main house when all said and done??

Why are you putting 2 X 30mA RCDs in series?? I think you'll find, that ...the hot tub's electrical installation will also incorporate RCD protection. You may find, you'll have multiple RCDs in series from what you have stated above.

Think you need to read the manufactures data sheets on this hot tub, and find out for certain if there is going to be a permanent water supply or not to this unit...