Strange problem with APC UPS 650

[Anonymous user]

I keep my computer running almost all the time. I rarely shutdown my computer. My computer is connected to my UPS 650. I'm recently seeing a strange problem with my ups. While the power is still on, it stops taking the AC power supply and switches to battery power. Why is it acting strange? May be power problem or my ups problem?

[Techie_apc]

The UPS function is to protect the connected equipment from power problems. So the UPS should transfer to battery whenever there is a problem with input power. This is normal operation of the UPS. Please note that while normal power may seem to exist, many power problems are transparent or invisible to a user. These unforeseen power problems, such as voltage wave shape distortion, Harmonic Distortion, and frequency variances, will cause the UPS to go to battery.

[Anonymous user]

Well I understood everything you said. Now you're saying me not to worry.
So do I have to change any settings in my Power chute (like setting sensitivity to low or something) ?

[Techie_apc]

You do not need to worry if the UPS transfers to battery due to power problems. You can find why the UPS transferred to battery mode ' under Monitor System-->Power Performances. The UPS sensitivity settings are user configurable. For your information, Battery longevity and service life of the UPS may be conserved by reducing the sensitivity of the UPS, as long as your equipment can operate normally under the conditions detailed below.

Any type of voltage disturbance includes; High/Low/No RMS Voltage, Total Harmonic Distortion(THD), Change in Voltage over Time(dv/dt), Frequency (Hz) out of tolerance.

High Sensitivity Mode
In the event of any type of voltage disturbance, the UPS will transfer to battery power and watch the AC line until it can transfer back to line. The
transfer time in this mode depends on how far the line voltage deviates from the sinewave reference.

Medium Sensitivity Mode
In the event of a RMS voltage-out-of-tolerance(High/Low/No) and RMS-rate-of-change disturbances(dv/dt) in the line voltage, the UPS will transfer to battery power and watch the AC line until it can transfer back to line. In this mode the transfer times are longer but still within acceptable
limits to insure the continuity of a computer's operation.

Low Sensitivity Mode
In the event of a RMS voltage-out-of-tolerance disturbances(High/Low/No) in the line voltage, the UPS will transfer to battery power and watch the AC line
until it can transfer back to line. In this mode the transfer times are longer but still within acceptable limits to insure the continuity of a computer's operation.

I hope that this information is useful.

[Techie_apc]

You are welcome!

Contact us if you have any questions in the future. Have a nice day!

[Anonymous user · Accepted solution]

Thanks for the information. I am convinced.