Problem with UPS 850

[aliiash]

My UPS 850 charging battery normally but if I press the power switch it work for only one second then turns off and not found any volt on output voltage port . What can I do in this situation ?

[dmill89]

Re: Problem with UPS 850

My UPS 850 charging battery normally but if I press the power switch it work for only one second then turns off and not found any volt on output voltage port . What can I do in this situation ?

How old are the batteries and have you checked the voltage? Many (most) UPSs have very "dumb" charging circuits (often only a constant float voltage with no regulation) that will try to charge a completely flat battery (I've seen many keep trying to charge a dead battery even after it had overheated to the point the case split open). Aside from that check for bad caps, if there is a fan make sure it is working (many consumer-grade UPSs uses cheap sleeve bearing fans with a high failure rate), and if you rule those out check any transistors to and relays see if they are good.

[aliiash]

Re: Problem with UPS 850

I changed the battery and charged. All components work normally, but if you press the power switch, UPS works for only one second and then turns off

[budm]

Re: Problem with UPS 850

How did you charge the battery? What is the Voltage at the battery terminals with and without the USP plugged into the AC oulet?

[SoporteHR]

Re: Problem with UPS 850

Hi. The new battery is realy new?

Check voltage of the battery with load. example a light incandecent.
If the battery voltage drops considerably with the bulb connected, it is damaged. (Nominal 12vdc, with the bulb, goes down to 7vdc) the battery is damaged.

Check the status of the switching relays, check the contacts and check their coils.

It also checks the transformer transistors or mosfets.

Perhaps this one is open and is not doing the work of generating the output voltage to the transformer.