RCBO reverse polarity

[MarkESpark]

Hi

I'm a first time poster.

I've just installed RCBO protected circuits for the first time.

I have connected the RCBO's in the CU. I have connected the N and functional earthing wires to the relevant bars.

The circuits are giving me reversed polarity at each socket on the ring. But when the circuit is moved to an RCD protected MCB, I re-test and polarity is confirmed to be correct at every point on the circuit.

As I say, it's a first time using them, am I missing something, or do I have a faulty RCBO?

I have the same issue with 3 circuits, all of which do have correct polarity outside of the CU, it's just when connected to the RCBO.

Many thanks for any advice

 

[Technician]

What instrument are you using and what shows

on the display?

Some here may be able to assist with how to

interpret the reads.

Could there be reverse polarity in the board?

 

[Des 56]

You havem't gone and done something silly like connect the neutrals to the same bar as the rcbo neutral(rather than at the rcbo),then your meter indicates a problem that you are assuming is wrong polarity

What meter was used

 

[binky]

post a photo please

 

[Ronan]

Check your neutral connection at the rcbo, they are usually in slightly further in than the line connection. And you can easily miss the connection when tighting it.

 

[MarkESpark]

The main tails into the CU are connected correctly. It's a split load, and all other circuits on the RCD side are reading correct polarity.

The actual circuit neutral ends are terminated in the RCBO itself, the flyleads are connected to the neutral bar.

It's almost like something is not connected correctly, but it all seems fine.

All RCBO's seem to be giving off cross polarity readings only when the circuit is connected thru the RCBO, but not when thru an MCB on other side of the unit.

RCBO clicked onto rail, with Neutral connected into RCBO port with Neutral flyleads next to it. Line also into RCBO in the port in front of Neutral The Neutral and Functional earth to the bars.

It seems like something is not connected, or connected incorrectly.

Have I missed something?

I'll try and post a photo when I get home tomorrow.

 

[m4tty]

What meter are you using? How do you confirm cross polarity? Are you a DIY'er?

 

[binky]

wild stab - tester not tripping rcbo is it

 

[alpha spark]

Have you got phase neutral connected in the Rcbo normally neutrals go in the shortest hole what make r u using

 

[NozSpark]

Have you got phase neutral connected in the Rcbo normally neutrals go in the shortest hole what make r u using

But not always,,, IIRC Crabtree Starbreaker ones are the other way round

The moral is "check before you connect"

 

[PC Electrics]

I bet you've connected your line and neutral the wrong way round at the RCBO output side. Check very carefully which port is which.

 

[MarkESpark]

Using Crabtree Starbreaker board and RCBO's

I have connected the N to the port to the back which has the N flylead next to it, as this is how all other RCBO set ups have been laid out when I checked.

I notice that someone else has said earlier that Crabtree ones are the other way round..... Perhaps this is the simple answer.

I did not want to try and swap ports in case I cross connected and may cause damage to the RCBO itself.

Can anyone confirm that with these make of RCBO you have the neutral connection to the front port.

 

[binky]

should be marked next to terminal.

 

[Badger]

neutral on crabtree rcbo is shortest and live conductor is longest neutral at front live at back ive connected hundreds of crabtree rcbos up

 

[MarkESpark]

Thanks Badger....

Just the answer I was looking for

Knew it was something small and simple

I appreciate your help.

 

[ProDave]

Please tell us what test equipment you are using.

If you have even the most basic test equipment for the job, you would be able to test the rcbo and determine which was the L and which was the N output terminal even if they were not labelled.

I fear you have no test equipment as such, just a plug in socket tester with 3 neon lights on it.

 

[batty]

Quite frightening really.

 

[ParkySparky]

Your saying you couldn't test/work out which was line/neutral terminals on the rcbo without the help of coming on the forum?

I know people seek advise but????

You not own a tester?

 

[betty swollocks]

Please tell me that wasn't the answer?!?!

 

[kelvfoozinda]

There's a better drawing on the side of starbreaker rcbo's to show L and N.