You are reading a single comment by @ectoplasmosis and its replies.
Click here to read the full conversation.
-
Thanks for the braindump, very helpful.
Are the Type B RCD requirements for ASHP documented somewhere? I’ve just had a 7kW Vaillant Arotherm Plus installed, and I’m pretty sure it’s wired via a RCBO in the main CU…
ectoplasmosis-
To protect people, type B universal-current-sensitive residual-current circuit breakers must be used if these are stipulated
for the installation site. Tripping must be short-time delayed and
suitable for the use of inverters (tripping characteristic > 1 kHz).https://www.vaillant.co.uk/product-images/0020330791-03.pdf.pdf
grams
If you're getting your CU upgraded it will more than likely have RCBO's, Heatpumps shouldn't be fed by an RCBO as the DC leakage current can cause issues. They require a Type B RCD, significant more expensive than a Type A.
https://www.youtube.com/watch?v=jzpZSTUCqTE&t=38s
You'll probably end up with a RCBO consumer unit and 2nd smaller Type B RCD board feeding the ASHP.
Or do what my installer did and slam an MCB into an RCBO board and provide a certificate stating a type B RCD had been installed. Returning to rectify once he was called out on it.
Other considerations/brain dump:
Location of ASHP from CU, as part of the wider work, would installing the cable now be an option
Location of EV charger from CU, same as above
What type of electrical supply do you have to your house, is it looped(in your meter cupboard, do you have 1 or 2(looped) black cables entering the property) if its looped the DNO will need to appove before an EV charger can be installed.
Size of DNO cut out circuit breaker, if my EV charger and ASHP are both running, I draw 54A, my cut out is 100A, but many houses are 63A