Query about an existing consumer unit...

[DNS1]

Hi guys,

As some of you will have read in recent weeks, I'm new to the electrics game and been working on a kitchen renovation project.

Today I got round to connecting my new cooker radial up and have done all the testing (very pleased with my new Metrel!)

Just noticed something odd about the consumer unit.

It's a 10 way Hager with a single RCD.

Incomer is on the far right of the unit, RCD is far left.

The RCD has 2 connections (the rightmost ones), both marked with an "N", but both appear to be connected to line (top is a feed from the incomer, bottom is the bar to the RCD protected MCBs.) The other 2 points (left hand side of RCD) are marked 1 and 2 and are connected to the incoming neutral and the bar for the RCD protected circuits.

I've done the automatic RCD trip testing with my Metrel and everything works ok.

But... Why are the incoming and outgoing line connectors connected to RCD by the neutral marked connections?

I'll stick some photos up tomorrow if it helps.

Excuse the probably stupid question, but as I say, I'm new to the game and have yet to work with anything other than perfectly installed college consumer units!

 

[jase]

The RCD should've probably been installed in the middle of the board so that from right to left you would have had: Main switch:non-rcd circuits:RCD:RCD circuits, if that makes sense, that way the busbar would have been put in the left hand side of the RCD and gone from right to left (hope this all makes sense)
It does not really matter that it has been installed the way it has, because all an RCD does is monitor an imbalance between line and neutral, pge 105 of the new green on site guide explains it fully

 

[DurhamSparky]

probably rejigged the configuration of the CU ..........!!

dont really matter what side of the RCD L/N is as it just senses an imbalance betwen the 2!

 

[Octopus]

A photo would be a good step forward.

 

[TaffyDuck]

Think jase is probably correct. I cant remember fitting a Hager in recent years where the RCD wasnt in the middle, therefore the guy who fitted it for reasons best known to himself must have taken the incoming Line + Neutral out of the top of the RCD, swapped them over, moved the RCD to the leaft hand side of the enclosure and fitted the outgoing neutral to the bottom left and the bus to the right. A good indication if this has happened will be if the blue and brown conductors from the 60947 main switch are a bit stretched. Hager always have quite a bit of slack in their correct positions so no slack means its been moved over.

 

[telectrix]

as above, but the terminals should have been re-labelled.

 

[hasel5]

Worked on one like this last week didn't notice any thing odd on the L-N arrangements going back today to connect the new hob so will checK

 

[DNS1]

Thanks for the replies guys!

 

[needasparks]

as above, but the terminals should have been re-labelled.

Unless half the install is rev-pol, hope not

 

[TaffyDuck]

Unless half the install is rev-pol, hope not

Half of France is, why dont we all do it that way, lowest common denominator