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.

[sib2024]

Hello did you found a solution to that problem with the fan ?

[Teken]

There is no (user adjustable) option for a On-Line Double Conversion UPS. The internal fan runs continuously at a slow RPM to keep the inverter circuit cool.

[EMPTEKNOLOJI]

Hello friends,

I have found a definitive solution to the noise issue of the APC Easy UPS On-Line SRV Series 1000VA-2000VA-3000VA, and now it’s almost completely silent. I’m planning to make a video about it. If anyone is interested, I can share it with you soon.

[EMPTEKNOLOJI]

Currently, in a closed environment, the APC Easy UPS On-Line SRV Series 3000VA UPS has been running for 24 hours, maintaining an operating temperature of 26 degrees Celsius. It emits very little noise and has become suitable for use in an office environment. I need another UPS to record my procedures on video and upload them to YouTube. My sharing may take some time.

[Mima]

Hey EMPTEKNOLOJI, looking into the noise issue myself atm.

I'd just buy some silen Noctua fans or sth. But if you have found a better solution, could you please share either what you did or the video that you planned to record?

Thanks so much

[EMPTEKNOLOJI]

Hey friend. First, I removed the front fans from their sockets. Then, I attached an old Intel CPU cooler fan to the grilled/vented area on the back. Since the original fans didn’t have PWM (Pulse Width Modulation), they were always spinning at high RPM. Now, the system is super quiet, and there’s no fan error. The internal temperature is 26°C in a closed environment, and the external ambient is 22°C. You only need to connect the positive and negative wires to the socket—the 3rd and 4th wires aren’t necessary."  Also, you can secure the processor  fan to the back of the UPS with a plastic clamp."

[Moerkreeke]

Hello EMPTEKNOLOJI, I am very interested in your solution. If you can make a Youtube video, please do.

Does your solution void warranty, or can you always reverse the changes?

[Mima]

Hey, thanks for the answer.
I have ordered some fans as well. Hadn't read your reply yet when I ordered, but I also decided to attach a cooler on the outside.
I also ordered 2 70mm fans to replace the original ones. But reading your reply, it seems that that's not even necessary. Wil have to wait a bit until everything is here and then do some testing.

Thanks again.

[Ekinox]

Hi,

The stock fan size (70x25mm) seems to be designed for industrial applications and as such doesn't seem to exist in quieter specs.

Alternatively, I have replace it with a thinner GELID Silent 7 (70x15mm) and a cable adapter to connect the fan with a standard 2510 4-pin connector to the XH2.54 2-pin socket of the UPS.

No fan error and a much lower noise level which makes it suitable for office use but also a much lower air flow.

I wouldn't advise it if the UPS is used with high loads, especially in On-Line mode (default setting, ECO disabled) with the circuitry needing sufficient cooling given by the stock fan.

With that said, it is really easy. Safety first even if obvious : remove the power plug and isolate the battery by removing the yellow battery connector at the back.

Open the UPS, disconnect the upper battery, unscrew the battery metal shroud, move the batteries aside, unscrew the front plastic, move the control module aside (mind not damaging the ribbon cable), unplug the fan, unscrew the fan, put the new one in and re-install everything back.

[abgpt]

Inspired by messages on this post, I decided to replace fans of my APC SRV3KL-IN.

I first confirmed that the label on the stock fans mentioned that those were 12V and measured that the dimension was 80mm.

I ordered 4 Noctua NF A8 FLX fans (3 needed, one extra just in case), while the fans were arriving I kept the batteries of the unit disconnected to give it ample time to discharge the capacitors etc.

Once the Noctuas arrived, I opened the unit and replaced all 3 Fans, quite a bit of task as the unit weighs 32Kgs.

The temperature before replacement was around 30-31 degrees (Celsius) and after it's now reaches around 32-33, but the relief - the noise is hardly noticeable, I keep this setup in my living room at my home and believe me the stock fans were like motors pumping water to 10th floor, now it's much lesser than the cooling AOI pump of my home lab server, perfect for home environment.

I measure the temperature through the USB serial interface and have grafana setup for historical data.

I have pics of the whole process, if anyone needs I can post here or somewhere else.

APC makes such great equipment, why not tie up with fan makers like Noctua and make those even better.

Disclaimer: opening UPS units is very risky, please take utmost caution, the stored electricity can cause accidents with fatalities. Also, it will void warranty.