EICR - RCD type

[firapara]

Hi guys,

I have an MK h7860s AC type RCD in my fusebox.
For EICR, is it a C2 or C3? Does it HAVE to be replaced with a Type A RCD? Or is it still acceptable?

Thanks

 

[Risteard]

Hi guys,

I have an MK h7860s AC type RCD in my fusebox.
For EICR, is it a C2 or C3? Does it HAVE to be replaced with a Type A RCD? Or is it still acceptable?

Thanks

That's entirely a matter for the inspecting Electrician, although what is connected to it may be a major factor in that judgement.

 

[pete01]

C3 normally

 

[Murdochcat]

C3

 

[ericmark]

Interesting question, it has been shown that an unidirectional RCD can go on fire if power is back fed through it in the wrong direction, and the phrase used is potentially dangerous, and if there is a chance that something will feed power in the wrong direction then an inspector would be correct to label it as a C2. Even if it's type A.

So it depends on what the RCD feeds, as to if it has any coding. I have swapped the RCBO that feeds my shed, as that socket is used to charge my sons' car when he visits, but all others are unidirectional type AC. But my supply is TN-C-S so the RCD is secondary protection, if I had a TT supply, then changing to type A would be more important.

So down to the inspector to decide if in your property there is a potential danger.

 

[ebee]

I have type AC in my home and do not intend to chage them anytime soon.
If I did change them (or if I got a lot more equipment of some substantial and modern electronics) then I might be inclined to change them.
I would normally envisage a C3 at most (about eqiv to the old code 4 if a PIR) .
I would not normally be unduly worried with most domestic properties but as a correctly perceived possible problem so new installs does make some sense not tocarry on with type AC.

 

[ericmark]

If I get any item which needs bidirectional RCBOs I will change, but otherwise the type AC will remain, they actually said they were type B on the boxes.

 

[JohnW2]

I have type AC in my home and do not intend to chage them anytime soon.

Same here. I have about a dozen type AC RCDs here, spread over several CUs, and I have no intention to change any of them simply because they are Type AC.

There is at least one person here who would probably argue that there is a need to upgrade them, because of an increase in collected loads likely to create DC current components, but I really don't think that such an increase has significantly occurred in my home - so that Type AC devices are probably no less safe today than they were when installed. in currents.

Don't forget that, until pretty recently, BS7671 was saying ...

For general purposes, Type AC RCDs may be used.

I would not normally be unduly worried with most domestic properties but as a correctly perceived possible problem so new installs does make some sense not tocarry on with type AC.

I don't disagree with that and, in any event, I doubt that we will have much choice, since I suspect that it will become increasingly difficult (eventualy impossible?) to buy Type AC devices from any of the mainstream wholesalers and suppliers.

Kind Regards, John

 

[morqthana]

they actually said they were type B on the boxes.

Won't that be the current curve, not the RCD type?

 

[ericmark]

Won't that be the current curve, not the RCD type?

Yes it was, it should have said curve B not type B, but said type B on the box.

 

[JohnW2]

Yes it was, it should have said curve B not type B, but said type B on the box.

I'm not so sure about that "should" ...

For very many years everyone had come to understand that "Type B" in relation to an RCD meant that it had a 'B curve' - so the "should" (or, rather, "should not") should surely be directed at the daft person(s) who suddenly decided to use that terminology to mean something different, shouldn't it ?

 

[ebee]

Yes indeed the overcurrent curve type and the RCD type are two different things, with a RCBO there arre two types of "types" so it can confuse some.

 

[Risteard]

Yes it was, it should have said curve B not type B, but said type B on the box.

It has always been known as Type B, Type C and Type D for circuit breakers.

 

[JohnW2]

Yes indeed the overcurrent curve type and the RCD type are two different things, with a RCBO there arre two types of "types" so it can confuse some.

It would not have confused anyone had they not decided to use very well-established terminolgy to mean something totally different