Caldera Tahitian Spa/hot tub install

[Mark.fardon]

Hi Anyone installed one of these ? I’ve been asked to install and the guy has sent me the blurb from manufacturer but is based on US wiring with GFCI instead of RCD etc. I’ve googled the uk version but still doesn’t look right I’ve asked him to get the UK installation instructions thought someone might have experienced similar ?

Edit:found some UK info

https://www.calderaspas.co.uk/sites/default/files/2020_utopia_50hz_owners_manual_rev_b_english_3.pdf

but talks about two supplies -16a and 25a for Hester and jets but I wouldn’t expect to take these both back to the house. So would need some form of local DB? Seems the tub has integral RCD so run some 6/10mm (length dependant haven’t done calms yet but suspect 10mm as 30 meters or do) SWA from an unprotected supply from the house.

Last time I installed a hot tub just needed 30A RCD supply and an isolator !

 

[Megawatt]

Hi Anyone installed one of these ? I’ve been asked to install and the guy has sent me the blurb from manufacturer but is based on US wiring with GFCI instead of RCD etc. I’ve googled the uk version but still doesn’t look right I’ve asked him to get the UK installation instructions thought someone might have experienced similar ?

Edit:found some UK info

https://www.calderaspas.co.uk/sites/default/files/2020_utopia_50hz_owners_manual_rev_b_english_3.pdf

but talks about two supplies -16a and 25a for Hester and jets but I wouldn’t expect to take these both back to the house. So would need some form of local DB? Seems the tub has integral RCD so run some 6/10mm (length dependant haven’t done calms yet but suspect 10mm as 30 meters or do) SWA from an unprotected supply from the house.

Last time I installed a hot tub just needed 30A RCD supply and an isolator !

Mark in the US a GFCI is the same thing as an RCD. I’ve wired quite a few hot tubs and everyone of the required a 50 amp GFCI breaker. I can’t say about the UK rules and regulations or the amperage since our voltage is 240/120 and the UK IS 400/240vac. Someone will be able to help you shortly since it’s 1:00 am over there. Good luck

 

[pc1966]

Looking at those instructions they are called "RCD breaker 16A", etc, so I wonder if they really mean RCBOs?

I don't see any mention of trip currents, often in the USA the GFCI are around 6mA while UK is typically 30mA, though a few make RCBO with 10mA trip that might be appropriate here. Maybe two RCBO to spread of internal leakage currents to minimise false trips?

 

[Mark.fardon]

Thanks. Ive read again and I don’t think the RCDs are integral it talks of a sub panel but I think that is to be supplied by the installer and each supply terminated in the control box. It also mentions bonding the steel rebar in the base which would mean needing to install an Earth marshalling terminal and a (10mm) SWA core used as a main bond back to the house or creating a TT and isolation from the PME. I will try and call the manufacturer and see if they have more info/advice. Someone must have already been through this though