Battery Charger or RCD fault?

[pmb]

Another electrics tripping thread. Over the weekend the RCD tripped in the van on my drive when all that was on was the charger. It may or not have coincided with SHMBO plugging a vacuum cleaner into the external socket. It wouldn't reset (a couple of days later when I got to look at it) without the charger being off and as soon as it was turned on it tripped again. I assumed it was the charger in the plug in systems ESM unit. Took the unit out and got the rivetted cover off to look at the pcb for the charger. All the components look fine and the pcb mounted fuse is intact. Thought about ordering a new £70 pcb but slept on it to give me some thinking time. Now thinking it could be the RCD (not a problem can source one) , with hindsight wish I'd tested a light or something in a socket. Think I will have to put the unit back in and try that. Your thoughts on which may be faulty please.

 

[GStockton]

Rcd failure is unusual , the only way to test it is with an rcd tester which tests its trip times and ramp tests the maximum tripping current, they normally trip when 25 milli amps are exceded and within 200milli seconds.
I would check the tightness off all the connections on the 230v input lead and input connections to the consumer unit as an rcd will not trip when tested with the test button when there is no power. also check the connections on the external socket as poor/ corroded connections can cause the rcd to trip.

 

[Guest]

I doubt the RCD is the problem so on the charger PCB, is the fuse ok?. Also and with fuse removed if not already blown,, what is the resistance between live and neutral conections both sides of the fuse holder?

 

[ProfJohnL]

I concur with other respondants,
I would point out that for your safety, any measurments you take as Gary has suggested must be carried out with the charger completely disconneceted from the mains. I will be interested to see what conclusions Gary draws from your results.

The give away is when you tell us the RCD will reset if the charger is off, but it trips or wont reset when the charger is on. If a live or neutral fault to earth is present the RCD will not reset, By turning the charger off, you are isolating the fault so the RCD will hold.

 

[pmb]

Thanks for the replies. I note from googling that you have worked on these Gary. I also note that there have been failures of this hager rcd , that combined with the fuse being intact , no visible damage or smell from the pcb and the fact that I hadn't tried another current source with the charger off made me question that it's the charger. With the fuse out the fuse holder contacts measure o/c as do the L and N input connectors. With the fuse in the L & N contacts read about 630k. The charger is completely disconnected from the mains Prof. I've worked on 20+ kv systems in the past (with it earthed down) , thanks for your concern.

 

[Guest]

Well the reading are as I'd expect so charger itself should not be the problem, strikes me then the fault is not actually on the pcb but on the supply and perhaps very close to it?

 

[pmb]

Had the unit back in the van today and when either a mains light or the electric heating was switched on it didn't trip. So it seems to me that it is the charger. All connections seems OK. I note the new pcb is an upgrade in terms of output. Any more thoughts please?

 

[pmb]

Apolgies for the bump. Finally got round to looking at this , tried a new rcd (for £9 it had to be worth a go) but same still tripping. Interestingly couldn't get it to trip when other things were turned on which it sometimes did when doing some other tests earlier. So took the charger out and have ordered a new pcb (Yes I know I could have replaced it with a standalone unit) . The fuse on the pcb finally blew which it didn't earlier , strange things these electronics.

 

[xtrailman]

These chargers would be cheaper than a diy repair.

http://www.amperorassociates.co.uk/Category/c-battery_chargers.html

 

[Gafferbill]

......yes I can recommend the Amperor chargers.........I have had the 18amp version fitted in my Swift for 3 years now and it is top notch....... Amperor Associates are also a good company to deal with....... It makes me wince when you see inferior chargers for sale at prices more than double what Amperor are charging!......(please excuse the pun!)

 

[bertieboy1]

I doubt if the fault causing the RCD device to trip is on the charger PCB.The circuits on PCBs are usually operated at around 5 volts DC and to get down to that voltage you have to transform the voltage down and convert to DC.
Any earth fault on the secondary side of a transformer (the low voltage side) will not be detected by an earth fault detection device monitoring the primary side (high voltage side) of the transformer.
This because there is no electrical connection between primary and secondary windings of a double wound transformer.
The fault will be on the 230Volt circuit - somewhere,could be anywhere between the RCD device and the 230 volt side of the charger.

 

[pmb]

Thanks guys fixed it. Put the new pcb in and seems ok. If you look here http://www.expluginsteve.co.uk/userimages/CHARGER-SPARES-ONLINE-SHOP%281959055%29.htm you will see the pcb and if you scroll down a cased charger that looks the same as the ampericor unit so I think it is the same 18A circuit board. Put the original rcd back in as well.