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?

 

[SPARTYKUS]

You've now intrigued me. It was my belief that an RCD works on the balance/inbalance of current in and out. ie. the sum of current through Line(s) and Neutral = 0. If you say only one is monitored how does it monitor the inbalance?

At the moment haven't got an old RCD to butcher!

I've got one...might set about it later

 

[Engineer54]

You've now intrigued me. It was my belief that an RCD works on the balance/inbalance of current in and out. ie. the sum of current through Line(s) and Neutral = 0. If you say only one is monitored how does it monitor the inbalance?

At the moment haven't got an old RCD to butcher!

My mistake yellowvanman, trying to squint looking at the diagram in the face of a budget RCD, and it's basically only a simplified diagram lol!!

Yes your correct on the balance/imbalance thing, but i'm pretty sure that there is a very good reason why they are polarised by the manufacturers. we'll just have to wait and see what Spartykus comes up with when he opens his duff unit up (with photo's hopefully)!! lol!! Might even get the contractor here to open an old MG unit, when i go back after the company Xmas trip...

 

[Stroppy]

The sensing coil couldn't possibly be 'measuring' one conductor only, what would it be comparing it against to get its trip current?

 

[MDJ]

Well IMO actually at the very least connecting the correct conductors to the identified poles is at least good practice, too much crap on here, any spark I employed connecting a neutral to the marked L connection on an RCD would get an early bath, regardless so there, if the RCD won't connect to the board you have then buy one that will, My god my Mentor would roll in his grave if I didn't consider the correct connections to the marked poles, too much Bull Sh*t today, get a grip and do the job right FFS