Question about APC Smart-UPS 620INET (SU620INET) UPS System

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A chattering sound is coming when a healthy battery is connected to the relevant terminals. The same sound persists when switching on 230 v ac. Keeping ac power on when I disconnected the battery the

My APC 620 VA ups needed battery replacement. For the time being to get the surge protection I was running the unit (without battery) with the help of a battery eliminator(out put 12V DC). I think it stopped functioning when one of the battery terminals got shorted with the chachis . But now I tried with a healthy battery. Whenever the battery is connected a chattering sound is coming from the unit. The sound continues even when the 230Vac mains is switched on. In this condition if the battery is disconnected then the frequency of sound is reduced to very low. The unit is not getting on at all. Model- SU620 INET (APC 620 VA). Can anybody help providing solution and circuit diagram?

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Try changing electrolytic capacitors in charging circuits and diodes near relays

Posted on Sep 29, 2013

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If the battery terminals inside the unit became shorted, it's really not a user serviceable problem. APC doesn't publish schematics.

Posted on Jan 01, 2013


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Posted on Jan 02, 2017

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SOURCE: APC Backup UPS Model # BK200C salvageable?

Yes, but the battery may not be any good, though, and trying to charge it may damage the charger. A new battery is about $20. The surge suppressor will still work without the battery as long as it is connected to a properly grounded 3-wire circuit. If you decide to take a chance and charge the old battery, take precautions like keeping a watch on it should it explode or catch fire. Not trying to scare you, just looking at worst case scenario.

Posted on Jan 27, 2009

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SOURCE: apc ups 650va no power when connctd to ac/bt wd power in on batry

Check the relay Circuit. the relay switch must be faulty

Posted on Aug 14, 2009

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SOURCE: I have an APC BE350U battery backup. When power

There are 6 outlets on that unit. Only 3 of them have battery backup. The other 3 are surge protection only. Are you sure of which outlets you are using?

Posted on Jun 20, 2010

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