Earth Leakage Detector

[JohnW2]

Yes, I know that and that is what Stillp mentioned but that's is not what's being talked about here, is it? The type 3 in the picture (page 1) relates to the MCB part, surely.

Maybe you have learned the lesson that the absence of quotes can cause misunderstandings and confusion

Coming, as it did, (without any quote) immediately after stillp's post including his comment about Type B RCDs, your post in which you said that "the type did not matter" in terms of residual current appeared to be responding to stillp's comment, not to the OP's situation!

Kind Regards, John

 

[EFLImpudence]

Fair enough.

 

[JohnW2]

Fair enough.

The relevance of this (stillp's comment) to this thread is that it seems that at least some treadmills may need a Type B residual-current protective device in order to avoid unwanted trips so, given that the OP has 'always had trouble with this treadmill', maybe that's his problem?

Kind Regards, John

 

[EFLImpudence]

I'm a bit confused.

Don't Type B RCDs, put in the simplest form, detect more types of leakage?

I.e. won't it be worse - or no better?

 

[stillp]

Did you read the link I posted?

 

[EFLImpudence]

Yes, that's why I'm asking.

Are you also saying the treadmill shall be put on its own circuit?

 

[EFLImpudence]

And BEAMA's

 

[stillp]

Are you also saying the treadmill shall be put on its own circuit?

543.7 in the BGB.

 

[stillp]

Yes, that's why I'm asking.

View attachment 112022

Perhaps that's less than perfectly worded. The DC component of the protective conductor current can saturate the sensor in a Type a.c. or Type A, so the RCD cannot 'see' the AC component.

 

[EFLImpudence]

Ok, I bow to your superior knowledge.

Is it that the a/c part of a B Type RCD is better than, or can work separately from, that in the the normal a.c. or A types?

 

[stillp]

Never thought of it like that. I think (I'm by no means an RCD expert) it's just that the magnetic curve of the sensor is such that it doesn't saturate.

 

[JohnW2]

Is it that the a/c part of a B Type RCD is better than, or can work separately from, that in the the normal a.c. or A types?

I don't pretend to know for sure, but my understanding has always been that, because (unlike A and AC types) Type B are designed to be able to cope with DC, that their function at AC is less likely to be messed up by the presence of (smooth or pulsating) DC currents. However, I may be totally wrong, so hopefully stillp can can confirm or refute.

Kind Regards, John

 

[stillp]

Yes, as I said in post #84.

 

[JohnW2]

Yes, as I said in post #84.

Thanks for confirming.

I went a little further in my speculation, so I wonder if you agree with what I said - that it's probably because the Type B is designed to be able to cope with DC that it doesn't 'get messed up' (probably because of the saturation you mentioned) by DC in the way that an A or AC might?

Kind Regards, John

 

[stillp]

Eh? It's integral to they way it's designed. Not sure I understand your question.