L and N markings on front of RCD

[kingeri]

Morning all, many RCDs have N or L marked on the front of them, to indicate polarity, but just looking at a bunch of Niglon pre-populated CUs and the RCDs all have N in the top left corner on the front, which I thought meant the left terminals are Neutral, but the Neutral bar is in the right hand connector. Any ideas? Am I just being dumb?

 

[Knobhead]

It would only make a difference if the neutral was a late break contact. I could be wrong but I’m sure you only get that on 3Φ&N units. So it shouldn’t make a difference. Just looks bad.

 

[DNS1]

DIYers install them the wrong way round...

On the plus side they still work correctly...

 

[kingeri]

The thing is that they were supplied like that.

 

[Engineer54]

Morning all, many RCDs have N or L marked on the front of them, to indicate polarity, but just looking at a bunch of Niglon pre-populated CUs and the RCDs all have N in the top left corner on the front, which I thought meant the left terminals are Neutral, but the Neutral bar is in the right hand connector. Any ideas? Am I just being dumb?

Yes, whoever populated those boards have not taken any notice of the polarity of the RCD's!!

Some manufactures work from left to right on populating design layout of CU's and others right to left....

 

[kingeri]

Looks like I'm going to have to put the RCD on the left. There are only 30 of them to switch over. Should keep me busy on Boxing Day! Thanks guys.

 

[Knobhead]

If you're recovering from Christmas, it could get worse :17:

 

[Engineer54]

The thing is that they were supplied like that.

Must have been a new boy on the factory assembly line!! lol!!

The L and N designations (when provided) on protective assemblies, indicates the internal circuitry polarity, which they want you to adhere to on final installation connections...

 

[kingeri]

If you're recovering from Christmas, it could get worse :17:

Judging by the volume of family members the wife is forcing me to visit on Xmas day, I think I'd rather actually do them on Xmas Day itself......would keep me out of the way. Baa humbug.

 

[telectrix]

i would re-label them.

 

[Geoffsd]

Why are there still questions like this?
Hasn't a manufacturer got a duty to state what is safe to do with a product?

As it's AC how can it make a difference?

Is it just so that the connections correspond with the diagram on the device? - except those which don't have L & N marked.

What about if you wanted to connect the supply to the bottom terminals?
Is that ok? If so, how can the polarity matter?

 

[Engineer54]

Why are there still questions like this?
Hasn't a manufacturer got a duty to state what is safe to do with a product?

As it's AC how can it make a difference?

Is it just so that the connections correspond with the diagram on the device? - except those which don't have L & N marked.

What about if you wanted to connect the supply to the bottom terminals?
Is that ok? If so, how can the polarity matter?

It doesn't normally matter if you supply top or bottom of a typical RCD device, ( depends on the manufacturers instructions) but if you look at the small diagram on the face of RCD units you will see that it's the neutral conductor that's being monitored, not the live conductor.... To be honest i can't remember ever seeing an RCD device that didn't have the connections marked L and N... lol!!!

 

[telectrix]

It doesn't normally matter if you supply top or bottom of a typical RCD device, ( depends on the manufacturers instructions) but if you look at the small diagram on the face of RCD units you will see that it's the neutral conductor that's being monitored, not the live conductor.... To be honest i can't remember ever seeing an RCD device that didn't have the connections marked L and N... lol!!!

so what you are saying is that the L and N connections must be in the L and N terminals as marked by manufacturer, no the other way round.

 

[Engineer54]

Makes sense to me Tel!! lol!!

 

[telectrix]

does to me as well, but what has happened to the OP is ( as i read it) the CUs have been assembled with RCD on the right, when they should have been on the left.

 

[Geoffsd]

look at the small diagram on the face of RCD units you will see that it's the neutral conductor that's being monitored, not the live conductor.

No that's not right.
They are both 'monitored' like a clamp meter.

Only when there is an imbalance will the residual current be noticed.

 

[Engineer54]

does to me as well, but what has happened to the OP is ( as i read it) the CUs have been assembled with RCD on the right, when they should have been on the left.

Who knows?? lol!! To be honest i've never heard of the CU/Device manufacturer. Perhaps the OP could contact them and ask some relevant questions, ...such as why are they supplying populated CU's, with the RCD's marked Neutral connection, connected to the MCB's buss-bar?? lol!!

 

[telectrix]

that's how i see it. can't see how they are polarity conscious. as long as the current in each pole is the same ( or at least the difference is < the actual tripping current required ) then they work as meant.

 

[MDJ]

If the poles are marked wrong then either the RCds concerned are mickey mouse in quality or they are the wrong RCDs for the consumer unit, why should anyone have to re labell a RCD? just not acceptable IMO, It should be very easy for the manufacturer to get this right, another ridiculous situation here, I have never come across this, so something is amiss surely, Whats going on then?

 

[Geoffsd]

These top of the range CUs do not mark the RCDs.
As you could swap the RCDs from one side to the other the polarity can't matter.