Burnt Out Neutral On Rcbo

[Y6 1878]

Yes that is the correct make and yes they are 2-module wide type.

They have agreed to replace the failed RCBO'S

and have the others returned for testing for possible faults. I can guarantee they are faulty know!!! Let's see what they have to say.

I will put some pics up as soon as poss

 

[apprentice87]

Hi Y6,

You mentioned does anyone have a way of measuring the resistance across the RCBO while the current is flowing..... Indeed i do!!!!!!

Simple voltmeter across it.... Divide the voltage recorded by the current flowing and you will have the resistance in ohms....

Now, square the current flowing times the resistance you calculated and you will have the power dissipated in the things in watts.....

You will soon see why they get hot....

john...

 

[ProDave]

These things are only supplying 16A so it will need a really poor connection to cause trouble.

Just 1 more post and you will have reached 10 and be able to post some pictures.

 

[Y6 1878]

They're are actually lower than that Dave at only 10amps this is why the only possible reason I can think of is faulty equipment.

 

[Murdoch]

They're are actually lower than that Dave at only 10amps this is why the only possible reason I can think of is faulty equipment.

10A supply to a caravan - is this correct?

 

[Y6 1878]

This is what the camp has always ran on and as the electricity bill is paid for by camp owner this is the size they want to stay on. I know it's low but if that's what they want ---

 

[Murdoch]

This is what the camp has always ran on and as the electricity bill is paid for by camp owner this is the size they want to stay on. I know it's low but if that's what they want ---

It maybe its what they want but what are the vans pulling?

 

[ProDave]

You should be able to post pictures now so we can see what you are on about.

 

[Y6 1878]

The max demand can vary but the max allowable is only 10amps

 

[ProDave]

I presume these are touring van pitches? 10A  would be a bit meagre for a static van.

 

[Murdoch]

What was in place before you installed these units?

I'd be getting my clamp meter out!

 

[Y6 1878]

Always been 10amp, they are static pitches. But even with overload you still shouldn't expect the catastrophic failure of a device just disconnection due to the overload.

 

[Murdoch]

Always been 10amp, they are static pitches. But even with overload you still shouldn't expect the catastrophic failure of a device just disconnection due to the overload.

could you try a 3rd party RCBO to see it that makes a difference?

Did the previous units use RCBO's?

 

[Y6 1878]

The ones which have failed have been changed so see how they go. No before this they had RCD and MCB but as the mcbs had been changed by a few van owners for ratings up to 32amp! In some cases, the site owners insisted on RCBO'S to make this more difficult.

 

[Y6 1878]

Hi onoff sorry for late reply, only just read your post, thought we had solved problem by replacing RCBO'S and putting problem down to manufacturers fault. But today another burnt out neutral on rcbo. As you said they are double pole 2 mod RCBO'S serial number VKL002. Rolec have been contacted and have sent me 12 replacements and asked for the damaged/faulty ones to be returned for testing. What this will prove now is anybody's guess!! But the new RCBO'S are "strangely" a new serial number ACEW0060. I have asked why this has changed and was told just a change of manufacturer but exactly the same device, sounds odd that two "exactly" the same devices would have different serial numbers. If there are any suggestions you may have a would be very interested to hear them. Thanks.

 

[Y6 1878]

Could anybody tell me how to post pictures. Thank you.

 

[Doc Hudson]

Could anybody tell me how to post pictures. Thank you.

Select the "more reply" option bottom right.



Then "attach files" option bottom left.



Then follow the prompts to "browse" and "add to post" as needed.

Doc H.

 

[Y6 1878]

Hi I have posted this question before but I still haven't come up with a 100% solution as of yet, was hoping the test and inspection forum May through some light on the issue.

The problem I'm having is burnt out rcbo's on caravan hook up boxes by burnt out I mean severe charring and melting to outgoing neutral terminal I've had eight of these go now and always the same terminal. The rcbo's are only ten amp which I appreciate are low for static caravan pitches but this is what they have always been on and what was required by camp to be fitted. The previous hook up boxes where RCD and MCB.

I have couple of theories as to the problem, would it be possible that the rcbo's are running at a very near maximum rated current for a period of time which is causing heating and then the failure I described??

But shouldn't the RCBO trip on thermal overload before the temp gets to high? And surely the device should be capable of running at its rated value (possibly)

Or are we looking at faulty equipment?? Any possible solution or help would be appreciated if any one has any ideas or has seen this problem before.

Thanks in advance

 

[Doc Hudson]

I have merged your threads together as there is little point in duplicating questions relating to the same topic in more than one place. This just makes things harder for other to follow and relate to previous comments.

Doc H.

 

[ProDave]

Assuming the terminals were tight, something I am sure you have checked, then I would say those rcbo's are not fit for purpose and would swap them for another make.

I'm tempted to say overload is the issue but if that's the case they should have tripped on over current.