Dead charger

[sjpt]

My son has our tandem at the moment, and has told me that the battery charger has just started causing his mains power to trip. It is a standard 42v 2a charger as supplied by Woosh with our XF07 kit about 2 1/2 years ago.

I haven't seen this myself yet, I'll be getting it back tomorrow and will do a few simple tests with a meter. Two questions:

1) Is there anything special to look out for that might be causing mains tripping?
2) If I need a replacement is there anything special to look out for or any suggestion about the best place to buy, or where certainly NOT to buy. I can see connector type and parity will be critical.

 

[WheezyRider]

My son has our tandem at the moment, and has told me that the battery charger has just started causing his mains power to trip. It is a standard 42v 2a charger as supplied by Woosh with our XF07 kit about 2 1/2 years ago.

I haven't seen this myself yet, I'll be getting it back tomorrow and will do a few simple tests with a meter. Two questions:

1) Is there anything special to look out for that might be causing mains tripping?
2) If I need a replacement is there anything special to look out for or any suggestion about the best place to buy, or where certainly NOT to buy. I can see connector type and parity will be critical.

With one of my Sans chargers, one of the toroids was not soldered properly onto the PCB. It didn't cause a mains trip, but the charger would not work. Once soldered securely in place it all worked ok.

Have a look out for poor soldering with a good magnifying glass. A lot of the stuff that comes out of China has poor quality control on the soldering and you can't take short cuts with lead free solder.

That said, if the mains is tripping, it sounds like either a short, or current is leaking to ground somewhere.

It could be a component failure, like one of the MOSFETS, or maybe a capacitor. When you open it up, put a multimeter on the components inside and look for shorts across components. Also see if there is a short between high voltage and ground.

 

[Benjahmin]

It could be a partial fault on your sons electric system. RCD's are particularly sensitive to any neutral/earth faults. If there is a pre-existing partial fault on the house wiring, then something that has a certain earth leakage (like an electronic charger) can cause nuisance tripping.
If it's the mcb that's tripping then that's an overload.
When did he last have his domestic system tested ? The recommendation is every 5 years.
I'd try the charger at home again before assuming it's crooked.

 

[sjpt]

Thank you for the suggestions.

It looks like a wrong diagnosis by my son; the charger appears to be working fine. I plugged it in here (as Benjahmin suggested); via a local switch RCD as well as the main one.

I don't think it's my son's wiring, which has been reasonably recently tested (and is I am sure in considerably better state than ours). He's currently blaming his bluetooth speaker or its mains adaptor; but that's for him to sort out.