APC Easy UPS On-Line SRV Series 1000VA - fan always on - how to turn off?

[exc_ngo]

Hello!

We are a small NGO and our APC Easy UPS On-Line SRV Series 1000VA fans keep on running all the time - even in Green Mode. The temp is far under the threshold. What can we do to spare energy and let the fan work only if there is no power etc, as we read in the post (https://community.se.com/t5/APC-UPS-Data-Center-Backup/Smart-UPS-1500-fan-always-on/m-p/337692/highl...). Thanks in advance for your help! Would appreciate it.

Best regards from Berlin,

Timm

[Mmmm]

I have exactly the same problem. Does some one know how to update fan speeds?

[Teken]

If your specific model UPS had a firmware update to address this issue - than yes.

Regardless of any firmware update APC does not incorporate a PWM fan on any of the lower end devices. Nor do they offer any user adjustable control over the fan speed, high / low limit, dwell / hysteresis 🤦‍♂️👎

As such, the fan speed is fixed and depending upon specific model. The fan will either be on continuously at a lower RPM when the internal temperature is adequate, than kick into high RPM when the internal temperature threshold has been reached. This behaviour is seen in all On-Line double conversion systems.

Other models the fan only comes on when hot, charging, on battery only mode. This is seen on many of the Line Interactive systems.

Other systems either don’t incorporate a fan such as the smaller Back-UPS. Or the fan cycles on-off-on / on-off depending upon how it was programmed by the manufacturer as seen in the Back-UPS Pro line.