Bus bar pins dont line up?

[confuzatron]

Howdy Pardners,
I've got a Wylex consumer unit with 'flexible bus bars'. Each piece of bar has one cranked pin at the end that's supposed to slot into the RCDs/Main Switch. But because it's cranked - offset a little compared to the other pins - when you tighten down on it the MCBs are pushed away from the DIN rail out of alignment with the RCDs. AFAICS it makes no sense for the end pin to be 'cranked' like this since the RCD live output lines up perfectly with the MCB live inputs. Any idea what's going on here? I can get away with cutting off this cranked pin because I dont need 5 circuits on either of the RCDs, but how come it's like this in the first place?

Here's what the bar kinda looks like with the pins facing you - 5 pins and one 'cranked' 'supply' pin at the end:


- - - - - _


UPDATE: here's some photos.

Terminals line up:

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• confuzatron
• 5 May 2012
• 1

Looks like main switch might be offset.

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• confuzatron
• 5 May 2012
• 1

With bar fitted, MCBs are pulled out of line.

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• confuzatron
• 5 May 2012
• 1

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• confuzatron
• 5 May 2012
• 1

Unclipped, the MCBs are way off.

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• confuzatron
• 5 May 2012
• 1

Cheers. [/img]

 

[Chri5]

The offset is right, but I can't remember where there is a required offset. It might be for the main switch down to direct circuits such as rcbos.

Although (and it's been awhile) are you sure the offset isn't for the rcd down to mcb.

Do check, because I'm sure there was an rcd where theres a cavity that looks the right place for the bar prongs is straight, but isn't.

If you are right then get a straight rail that has enough ends to cover both used and any spare ways for future use. You can straighten then out with heat and grips or a vice, but the prong offset might not be in sync with the set.

 

[securespark]

You have a configurable board. You decide how many ways on each bar. Have you got the instructions?

You shouldn't really attempt to put it together without. There is one offset pin on a busbar that is intended to fit into a main switch or RCD.

The rest all line up with each other and they are intended for the MCB's / RCBO's. The instructions should say this & usually there is a sticker or some indication on the busbar that this is the case.

Don't butcher or alter the busbar with tools or heat. If you have already, give Wylex a ring on 0161 998 5454 and ask for some spares. Don't risk fitting butchered parts.

 

[AndyPRK]

Are you using the very latest style of MCB ? Post a pic.

You could of course just cut off the odd end, assuming the bus bar would still have enough ways

 

[RF Lighting]

The crank is supposed to be there, and everything will line up properly. You must be doing something wrong.

 

[AndyPRK]

I think that have moved the connection point on the NHX MCB's.

 

[sparkwright]

Tempting as it is to alter the busbar, it's extremely likely everything is as it is supposed to be.

When fitting all the circuit breakers, it is common for them to be out of alignment.

So you loosen them, hold everything in place, then tighten them again.

Usually easier to tighten them first from the RCD end.

My advice is do not alter the shape of the busbar, and keep trying (calmly) to fit the MCBs neatly.

 

[securespark]

Did you buy the CU new?

Have you rung Wylex / Electrium to discuss your dilemma?

Maybe (just maybe) you are trying to fit the wrong the MCB's?

Or maybe (far less likely) they wrong busbars are supplied.

 

[confuzatron]

Cheers folks. I've added some photos to the original post.

This is a Wylex kit with MCBs and an RCBO supplied. I can't see how these bars are right. They are all the same and look like suitable for connecting the main switch which is offset (makes sense given your comment Chri5), but otherwise they just don't line up. Normally I'd always assume I'm being the eedjit, but in this case it looks like a cock-up? I'll phone the support line in the included material.

 

[sparkwright]

Can you explain the last photograph a bit more? It looks OK it that one, but not sure what you have done in that one.

Many consumer units can have these problems where the MCBs are quite crooked, and it doesn't look too pretty in your pictures.

Very often things do move about, and fitting the lid does seem to straighten things up. Hardly satisfactory from an engineering point though, is it?

It would be worth contacting Wylex. Maybe a busbar without a crank is the answer.

Just a couple of years ago Wylex were doing two versions of busbar to fit all their stuff - one with single prongs, and one with 'U' shape slots cut into it.

Did you buy all the bits as one complete package?

Wylex did alter the design of their MCBs about a year or so ago, yet they should be compatible with each other.

 

[sparkwright]

Just had a look at an unused split load Wylex board from 2007 which I never used due to 17th Edition changes. Board NHRS6604.

It has the MCBs from 2007.

It has the busbar with the U shape notches in it - which is not like yours.

This busbar fits more towards the front cover of the board, in slots formed on the MCBs and RCD. The busbar has a slight crank.

Looking at this board, if a busbar with prongs like yours were to be fitted, a crank would definitely be required.

Yet it does appear by your photos you don't need the crank.

Was this board of yours assembled fully when you bought it, and what was bought separately?

Without cutting the busbar, have you tried fitting the busbar the other way round so the crank is where unused MCBs would be?

 

[confuzatron]

Was this board of yours assembled fully when you bought it, and what was bought separately?

It's an all-in-one kit - Dual RCD 'high-integrity' board with RCDs MCBs and an RCBO all included. In terms of assembly the RCDs are wired up to the Main Switch and neutral bars. So in theory, it should all work together!
The other kind of bus bar (fixed) that goes higher up - under the screws - gets a mention in the instructions.

 

[sparkwright]

Can you explain the last photograph a bit more? It looks OK it that one, but not sure what you have done in that one.

 

[sparkwright]

Are you certain each prong sits correctly in each terminal, and you haven't missed the 'slidey bit'?

Sorry to get technical.

 

[confuzatron]

Are you certain each prong sits correctly in each terminal, and you haven't missed the 'slidey bit'?

Sorry to get technical.

Haha I just googled slidey bit so no worries. Yes, the bar is clamped properly in each terminal with the sliding part of the terminal beneath pulled up against the pins.


That last photo above is with everything tightened up but the MCBs unclipped from the DIN rail so they find their own position - they sit a good 2 or 3mm too high

Couple more pics:

Bar flipped to avoid using cranked pin - looks correct.

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• confuzatron
• 5 May 2012
• 1

The bar with insulation off:

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• confuzatron
• 5 May 2012
• 1

Thanks.