350V U.P.S d.c bus positive touches earth?

[Toxic Gerbil]

Hi guys,

Im a new member and a have kind of a weird question.

I am a u.p.s technician and the other day I came across a 5kva u.p.s with 16 x 12v7ah external batteries connected in series that charge @ 13.5 vdc each x 16 = 216 vdc optimal charge rate.

Anyway, back to the point.
The battery cabinets earth, which is connected to the u.p.s cabinets earth, which is connected either to the buildings earth leakage or dirictly to earth by means of a copper rod, came loose and shorted over the positive terminal which is @ 216vdc supplied by the u.p.s charger board (which has no damage).The 3 x 3300 mfd 350vdc caps swelled and opened circuit as a result and need to be replaced, but other than that I find absolutely no damage.

My question is : what actually happens when the 216vdc positive from the charger is shorted to earth. e.g: do the caps just keep discharging down to earth until they short or explode, can that dc voltage affect other equipment on same earth line etc...?

Please if anyone knows, I would really like to know

Thanks.

 

[duffy]

Give you a big IxR drop, I suppose you could wind up seeing most of that 216V on other grounds in the system, depending on what path it took.

 

[Hero999]

It's knackered.