The schematic of my ASHP system design calls for a "30mA Type F RCD". I think that's out of date now and would need to be an RCBO. What type of RCBO do I want to use for this? Type / Curve and how do I reflect the "Type F RCD" requirement?

 

 

From Ecodan Installation Manual:

Edited September 18, 20233 yr by MortarThePoint

The heat pump guy told me to run a 6 mil cable with 40 amp breaker 

An electrician friend to me to run a 10 mil cable with a 40 amp breaker 

The leaflet states 40 

 

https://electrical.theiet.org/wiring-matters/years/2019/77-september-2019/which-rcd-type/

 

https://www.eaton.com/content/dam/eaton/products/electrical-circuit-protection/circuit-breakers/xpole-rccb/eaton-xpole-residual-current-devices-type-f-brochure-br019005en-en-us.pdf

 

I would be on the phone to the supplier & manufacturer of the heat pump for direct tech support, and get their responses in writing before planning your electrical arrangement. We are just simple folk with too much time on our hands  

One way to resolve this is to Have the MCB in the consumer unit feed a armour cable to a surface enclosure that contains the type f RCD.( not necessary if the same make of mcbs/ RCD is used as you can’t mix and match inside the same consumer unit 

then cable to the ASHP as normal.

best advise as Nick says is get confirmation from the manufacturer.

your spark will decide if it’s 6mm2 or 10mm2 based on the circuit design.

Given how hard it is to find Type F RCDs or RCBOs from sensible places I'm doubtful the majority of people are using them. CEF list a 40A type F RCD for £160+. That's about all I've found 

https://www.automationdatabase.com/products/siemens-5sv3314-3?variant=14325568967&currency=GBP??

C20 for my 9kW unit. Stuff it on a c32, it’ll be fine.

 

I ran mine on a 13a plug for a few days so it’s hardly a big deal 🤣

It's the DC component that's the issue, not the actual currrent and that could well be RCD brand specific. The original incoming 100mA type-S I installed in our meter box was sensitive to our CE-iVT9, as soon as the inverter was energised (but before actually driving the compressor to any degree) it would trip out.

Check out Schneider Type B si RCD & RCBO types. I've always used where inverters firung up cause nuisance tripping:

 

https://www.se.com/uk/en/product-subcategory/1620-acti9-residual-current-devices-rcds/

1 hour ago, dpmiller said:

It's the DC component that's the issue, not the actual current and that could well be RCD brand specific. The original incoming 100mA type-S I installed in our meter box was sensitive to our CE-iVT9, as soon as the inverter was energised (but before actually driving the compressor to any degree) it would trip out.

Despite the the kW rating of an ASHP the electrical supply has to allow for the millisecond jump of power when the ASHP switches on. Fuse type , size of cable and fuse amperage all different than we expected, prior to reading the CE-iVT9 installation manual.  

The Schneider si types are not time delayed but protect against transient inrush current on startup. They've solved a lot of headaches for me where the client/spec called for a 30mA RCD.