Type AC RCD's and EICR's

[goasis]

Hi all. What are your thoughts on coding type AC RCDs when doing EICR's?
I understand the issue on DC currents preventing RCd's from functioning correctly.
The Am2 version of code breakers suggests a C2 coding for: "....type AC RCD and has pulsating DC currents from connected equipment such as EV,PV, switch mode power supplies, domestic appliances with VSDs etc..."

I get the first two, (EV,PV) they should be fairly obvious, how are we making judgement calls on the other items, esp if we are in an unoccupied house between tenants for example?

 

[pc1966]

I would have hoped that the BPG#4 would have been updated by now for AM2 but nothing yet.

My own feeling is C2 would only be merited if the sockets are likely to be used outdoors and it has PV/EV, as that is when the possibility of DC blinding of the RCD is a real risk to life in the event of a damaged extension lead, inverter fault, etc. But for sockets in general it would have to be minimum C3 these days as practically everything has electronics in it.

 

[brianmoooore]

Recently installed full RCBO boards and now you want to C2 them? There'll be blood on the streets.

 

[pc1966]

Recently installed full RCBO boards and now you want to C2 them? There'll be blood on the streets.

Only for type AC with EV/PV use-case. Which was probably against the MI at the installation time anyway.

 

[pc1966]

Though having said that, a friend of mine has a ABB solar inverter and the MI actually says type AC is fine!

 

[brianmoooore]

The EV that I've installed (just the one) has a built in Type A RCD, and is installed with no other RC devices between it and the DNO source.

 

[goasis]

Only for type AC with EV/PV use-case. Which was probably against the MI at the installation time anyway.

Not according to codebreakers.....

 

[pc1966]

Not according to codebreakers.....

Probably not. But don't they list no RCD as C2 always, whereas BPG#4 has C3 or C2 depending on the circumstances?

The problem is how do you deal with plugged-in equipment, as if you have to cover all possibilities we would have to fit the horrendously expensive type B in that case!

 

[UNG]

Not according to codebreakers.....

Why is this book the go to it doesn't deserve the ink and paper it uses in it's production

 

[goasis]

Why is this book the go to it doesn't deserve the ink and paper it uses in it's production

I think it's a useful tool to help you think through the inspection and prompt you as to things to look for and consider. My point was to get thoughts on the suggestion that pretty much all type AC rcds you come across are a C2, or how do we go about making a judgement as to whether there are likely to be pulsating dc currents present

 

[UNG]

I think it's a useful tool to help you think through the inspection and prompt you as to things to look for and consider. My point was to get thoughts on the suggestion that pretty much all type AC rcds you come across are a C2, or how do we go about making a judgement as to whether there are likely to be pulsating dc currents present

The problem is a one size fits all approach doesn't always work and the it must be right cos it says so in codebreakers does not absolve the person doing the EICR from making the correct decision, the most useful tool is actually BS7671 and not some book that carries the opinions of those who have not seen the exact scenario and circumstances you are working with. If you speak to people who contributed to codebreakers they don't necessarily agree with all the outcomes listed so it is clearly flawed