Extending a neutral cable in caravan power module

[scott488]

Hi All,

I noticed a burning smell coming from the power module in our caravan, when I've stripped it down, I've found that the neutral cable has started to melt / burn just as it connects to the RCD. The bottom of the RCD is also damaged.

Firstly, what would cause this to happen?

Secondly, can I simply replace the RCD and rewire? If I can, the neutral cable is coming from a mate-n-lok connector, so can this just be extended with the same rated cable and a connector. Once the damaged section is cut off, it would be too short to reach the RCD.

I've contacted the manufacturer for replacement cables, but they no longer make the power module so I'm not hopeful.

Thanks
Scott

 

[securespark]

Photos!!!!

 

[PrenticeBoyofDerry]

The burning could well be down to a loose connection at the RCD neutral terminal.
You have just summed up what is the best way forward, replace damaged cable and RCD.

 

[scott488]

Couple of photos of the offending items

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• scott488
• 3 Apr 2013
• 1

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• scott488
• 3 Apr 2013
• 1

 

[333rocky333]

Looks like trirated cable,often AWG sizes its expensive and not usually available in short sections and a new bit would require you to fit ferrules really, depending on the length you may be able to buy a bit desighned for a consumer unit that would proberly do the job

 

[333rocky333]

cable is coming from a mate-n-lok connector,

Got a photo of that

 

[scott488]

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• scott488
• 3 Apr 2013
• 1

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• scott488
• 3 Apr 2013
• 1

If I cut back the damaged part of the neutral cable it will no longer be long enough to reach the base of the RCD so I need to either replace or extend it. I would have thought replacing it would be difficultdue to the connector.

The cable is marked H07V2–K 450/75

 

[333rocky333]

Does it need that connector wheres the cable, if any from the other half of it go to

 

[Iggifer]

does the 4-way connector go to your 16a feed from the hookup?

 

[scott488]

The connector shown in the photo is pushed through a hole in the module (along with others) and this is where another connector plugs into it. I'm guessing directly from the 16A supply. There are some wiring diagrams of the module online, I'll upload one tomorrow if I can.

 

[333rocky333]

They look like blue ferrules, thats french colour code for 2.5mm
The HO7 is tri rated so that cable can carry higher current and temperatures than standard 2.5
Your first pic made it look a lot bigger, so sorry for that

 

[scott488]

Morning All,

Thanks for the help. So far.

Is it possible to safely join tri rated cable and if so how should it be done? Don't suppose anyone knows where it can be bought in short lengths? I probably need 6 inch at the most

Scott

 

[ericmark]

There are a number of ways to ensure a strand of cable does not jam in the compression mechanism which holds the cable. ferrules, pin crimps, brass shimming, and tinning all do the same job. With some RCD's there is a higher chance of a problem than others but with 2.5mm cable it may also be too small in diameter to be gripped properly I have even seen it bound with a 1.5mm solid. I don't like tinned ends. Often well twisted is enough.

What you have is a caravan that because it is towed flexes and need flexible cable and a RCD designed to be fixed and it just takes some common sense to decide if the cable is well gripped.

But also add vibration and know problems with screw connectors where we know they can become loose due to vibration. So on the annual inspection all screws should be checked for tightness.

Personally I would change the RCD as the threads may be damaged giving a false impression of tightness. If the cable is long enough then nothing wrong in cutting off damaged bit. RCD's should always be tested with a proper meter after fitting as twisting or warping during fitting can stop them working within the prescribed time. But since there will also be one on the caravan site so belt and braces situation I would not be too worried unless to travel abroad.

As a P.S. I always screw the clamp down and up without a cable in first I have come across faulty threads from new.

 

[scott488]

Thanks Eric mark, but what about if the cable is too short once the damaged section is removed?

 

[plugwash]

Personally i'd join on a new section of suitable wire with solder and heatshrink.

Replacing the whole wire would be the ideal soloution but the trouble is identifying exactly what make and model the connector is and then buying the appropriate pin and tooling is likely to be expensive.