Burnt out rcd

[Rockomuir]

Evening all, been called out to a campsite to a hook up that looks like a dalek. This hook up is supplied by 32a on 6mm 3 core swa and supply's a 40amp rcd and 2 c6 mcbs. The mcbs then feed 2 of the blue industrial 3 pin outlets. The rcd was burnt out through the side and knackered. I am going up there today to do a proper test and inspect but just after some advice about the burnt out rcd.

These plugs are only supposed to by for lighting in caravans so could the burn out be from overload or just a faulty rcd. I do not want to change the rcd until I have found a cause for the problem. Has this happened to anyone before. I know that this seems like an obvious question but I have had faulty rcds before but not a hole in the side of it.

 

[Richard Burns]

If it is only on a C6 MCB then I would expect someone has been trying to use more power and tripped the RCD a lot perhaps causing the contact terminals to become corroded and therefore overheating the terminals to the point of melting the side out.

A melt on the side is usually down to a fault on the switch terminals inside the unit, a melt from the top is down to a poor termination of the cable.

 

[malcolmsanford]

The RCD is rated at 40 amps you say so I doubt very much you are having an overload issue, the C6 MCBs will tripp a long time before you damage that RCD even if both MCBs are being driven at maximum load.
There could be several reasons the RCD has burnt out

• Poor connection
• Old RCD and as Richard said the internal points have burnt out
• Could be environment. It's on a camp site as you said so you have temperature extremes, and possibly damp

Give the circuits(s) a good test and replace the RCD. See what the "pods" are pulling and see if the IP integrity is good.

 

[Rockomuir]

Thanks for the replys, water ingress could be an issue, and the unit looks pretty old. I will give it a full test when I go up there tonight and hopefully solve the issue .

 

[Nooteboom]

Evening all, been called out to a campsite to a hook up that looks like a dalek. This hook up is supplied by 32a on 6mm 3 core swa and supply's a 40amp rcd and 2 c6 mcbs. The mcbs then feed 2 of the blue industrial 3 pin outlets. The rcd was burnt out through the side and knackered. I am going up there today to do a proper test and inspect but just after some advice about the burnt out rcd.

These plugs are only supposed to by for lighting in caravans so could the burn out be from overload or just a faulty rcd. I do not want to change the rcd until I have found a cause for the problem. Has this happened to anyone before. I know that this seems like an obvious question but I have had faulty rcds before but not a hole in the side of it.

I am looking at a Rolec C16 RCD just replaced ,a similar use to above and I am wondering if the custormer/user on site held the trip switch up?

 

[littlespark]

I am looking at a Rolec C16 RCD just replaced ,a similar use to above and I am wondering if the custormer/user on site held the trip switch up?

7 year old thread, mate.

Start a new thread if you have a new question.

(But I would say, yes, customer may have held switch up until it’s stuck)

 

[brianmoooore]

Never come across a MCB (or RCD) that can be held on against a fault.

 

[littlespark]

Never come across a MCB (or RCD) that can be held on against a fault.

I have… on our caravan park
One customer jammed the switch with a pen lid, another superglued it.
Weirdest was one guy that the changed the 16A to a 32…. Cut the toggles off the switches and glued it to the other… so a quick glance, it was the same colour. (The 16s had a blue switch, 32 possibly red)

Every one of them got a stern letter, explaining the dangers, and an eviction notice.