Burnt Out Neutral On Rcbo

Hi this is my first post on the forum so hello to everybody, the issue I'm having is burnt out RCBO I'm caravan supply box on outgoing neutral side?? I know the obvious answer would be loose neutrals but I have installed 137 and after a few weeks of use 7 have now burnt out. I may be over thinking the problem and it could be as simple as loose neutrals but this is unlikely a I always make sure terminals are right. The only other answer could be faulty RCBO'S ?? Has any body else had any issues with faulty RCBO'S? I can't really put the manufacturer of the equipment on hear but they are a well known caravan box manufacturer.

Thanks for any help.

What make is the RCBO? Has the supplier replaced them FOC?

Seems worrying - I would call the manufacturer.

Rolec rcbo and box. Not been replaced FOC as yet but I'll be contacting manufacture direct as you say sounds worrying.

id be wanting payment for replacing their faulty parts too, not just a replacement

[SIZE=10.5pt]The first obvious question has to be are you using a torque screwdriver and tightening to the manufactures specification?[/SIZE]

[SIZE=10.5pt]Doc H[/SIZE]

That was my first idea but the point at which the rcbo is failing is connected in the manufacture of the box and therefore we only "check" for tightness.

You should ALWAYS check ALL connections in a CU. Especially those done in a factory and for a product that cheap!

how did you know about the failure of the 7 - did the power go off? have any others been checked for sign of damage, even if they havent failed completely yet?

As I said all manufacturers connections whete checked and I don't think that Rolec are the cheapest out there by any means! Also a loose connection seams unlikely as the failure has been in the same place on each box seems coincidental that only these connections would have been left at an in-correct torque whilst every other connection is fine. This in my mind points to a high resistance joint possibly in a faulty RCBO, as Rolec obviously don't manufacture these RCBOS I was curious as to who does.

Only knew about failure when power went off Andy and yer I've checked many boxes for any sign of damage but as of yet nothing found, will continue tomorrow on the rest of camp.

Could anybody suggest the best way to test for high resistance under load across the RCBO? Also ther have been no ferrules used in the manufacture of these boxes so the fine cores of the fly leads are spread thus creating a high resistance joint? Possibly??

thermal camera would show a potential fault

Yet it would show a potential fault but nog the reasons why fault is present.

Is the failure where the neutral fly lead from the rcbo screws into the neutral bar?

If so what sort of termination is on the end of the fly lead?

The failure is the actual connection at outgoing neutral of RCBO. No neutral bar just connected from din rail connectors direct to RCBO.

pictures speak a thousand words

Y6 1878 said:

That was my first idea but the point at which the rcbo is failing is connected in the manufacture of the box and therefore we only "check" for tightness.

Click to expand...

Y6 1878 said:

The failure is the actual connection at outgoing neutral of RCBO. No neutral bar just connected from din rail connectors direct to RCBO.

Click to expand...

I'm confused.

First you say it was a manufacturers connection that can only be the fly lead or the incoming connection to the busbar.

THEN you say it's the outgoing neutral connection that presumably you made off?

A better explanation is needed please.

another 3  posts and you will be able to upload some pictures to make it all clear.

The caravan box comes prewired by manufacturer the one and only connection made by ourselves is incoming suppły to din rail connectors. No outgoing suppły is connected apart from that made via the 16amp plug connection to the van itself. I will post a picture to clear up any confusion Dave but these are pretty standard connections for a caravan hook up box.

So the question comes back to exactly WHAT is failing?

And are you checking the tightness of whatever connection has failed as you install them.

Only a couple more posts and you will be able to post some pictures, so answer that question and you will be almost there.

if its a pre-wired unit with just supply in for him to connect, then there shouldnt be any connections he needs to check

sounds like a faulty batch of RCBO's, or some other manufacturing issue

This make is it?

http://www.rolecserv.com/leisure/product/touring

Company based in Boston, UK. 

Just out of interest would these be 2-module wide, true DP  RCBO's I wonder...............