RCD or RCBO types for an inverter heat pump.

[wannocks]

Hi.
I'm looking for some guidance on RCD/ RCBO selection for heat pumps. The heat pump manual states:

The RCDs follow the standards and regulations but may be not applicable for heat pumps that have high frequency ampere peaks caused by the inverter technology.
Therefore, RCDs need to be specified beyond the standardized 1 kHz.

Then offers some suggestions of suitable types:

Usage of RCDs type B specified > 1 kHz and short-time delayed.

The problem can be avoided by the selection of the right RCD.



Tested brands:

Brand	Type	Specifications
ABB	Type B Type B Type B+	2pin 40A 0.03A 2pin 63A 0.03A 2pin 63A 0.03A
Doepke	Type B SK Type B NK	2pin 40A 30mA 2pin 40A 30mA
Schneider Electric	Type B SI Type B SI	2pin 40A 30mA 2pin 63A 30mA
Siemens	Type B Type B	2pin 40A 30mA 2pin 63A 30mA
Legrand	Type B	2pin 40A 30mA

The main problem is nuisance tripping.
I work on these heat pumps, so am looking for some help identifying suitable/ unsuitable breakers when visiting sites for tripping problems.

 

[ericmark]

I know you can get linked RCD and MCB so work like a RCBO, but not seen any single width RCBO's other than type A or AC.

I know with EV's they use type A and a unit to auto disconnect if over 6 mA DC, but not sure if there is a type F that is also type A?

 

[flameport]

Therefore, RCDs need to be specified beyond the standardized 1 kHz.

That means it must be Type F as a minimum, optionally Type B or B+ assuming that an RCD is needed at all.

A heatpump as a device does not require any RCD, however the circuit to it might, but that depends on how the circuit is installed.
Entirely possible to have the circuit installed so that no RCD is needed.

but not sure if there is a type F that is also type A?

All Type F include the equivalent of Type A, which all include AC.
Type B includes F, A and AC.

https://www.electrical-installation.org/enwiki/Types_of_RCDs

 

[wannocks]

That's what I understand, that as a fixed appliance a heat pump does not have to have an RCD.
Does this change if its a TT supply?
Design of the circuit I leave to the sparkies!

 

[EFLImpudence]

No appliances have to have an RCD.

 

[flameport]

Does this change if its a TT supply?

In most cases a TT supply will require RCD protection for all of the circuits.
If an RCD was required because of that, then it would have to be selected based on what type of loads were connected to it.
The same applies to a TN system where the circuit is installed in a way which requires RCD protection.