APC 1500 UPS sometime makes noise, is it something serious?

[sairfan1]

My APC 1500 UPS sometime makes noise for a while, I want to know does it need some service, some part needs to replace OR its not safe to leave it running?  I uploaded video at Youtube for reference

https://youtu.be/KgtG6Dz1KVM

[argentas]

Difficult to tell from the video, but could it be a noisy fan? I replaced the fan in my APC UPS recently because the bearings were on their way out and it was causing an intermittent vibration.

But in relation to your original question - how often is 'sometimes'? and for how long is 'a while'?
Does it make this noise when running from mains power, or only during a powercut whilst running from battery?

These UPS tend to perform a self-test periodically - I think mine is configured to do this once per week, and it lasts around a minute. During that time it will be running from battery power, the fan will be running, and there will be noise from the inverter.

[DrGeoff]

Are you sure that isn't the self-test?
Most UPS self-test the battery loading at least once a week by switching to inverter supply for about 10 seconds and measuring the battery discharge rate. This is how they report failing batteries.

[sairfan1]

Sorry I missed the conversation. its not a fan noise its something like sometime we get from transformers.