Two years ago I wrote about the second set of replacement batteries for my APC Symmetra RM UPS. Those batteries are still working, but at 8+ years old the various fans in the UPS were getting a bit tired and making various high-pitched whines and grating noises, so it was time for a complete set of replacement fans.

There are 3 different types of fans used in the Symmetra RM – ones in the SYPM2KU power module (2 fans each), ones in the SYTF2 transformer (2 fans each – see footnote), and one in the Symmetra RM chassis itself.

The fans used in the power module are Mechatronics F8025X24B-FHR which is rather hard to find. I purchased mine from Online Components. You will have to splice the connectors from the old fans onto the wires of the replacement fans. If your UPS has sufficient redundancy to allow removal of one power module at a time, you can replace these fans without shutting down the UPS.

The fans used in the transformer are NMB-MAT 3115PS-12T-B30. These are widely available and I purchased mine from Newark Electronics. Note that it is perfectly normal for only one of the two fans to run – the other one is used only when the transformer detects an overheating condition. The cable for these fans just plugs into the fan – no re-wiring is necessary. You will have to shut down the UPS and disconnect the transformer to work on the fans, however.

The main Symmetra RM fan is a Comair-Rotron FE12H0X-039453 which is a semi-custom part for APC. This fan also has a sensor to report its speed, so you can’t just substitute a random 80mm fan. Fortunately, APC makes it possible to order this part at a reasonable price. It is APC part 490-0024B. I ordered mine from CDW, and despite it being a special-order item, it shipped rapidly. This fan comes with the necessary connector pre-installed. It can be replaced while the UPS is running, however the UPS MUST be placed into bypass mode via the switch on the rear panel, or the UPS will shut down with a “System fan fault” error when you unplug the old fan.

The old fans provided nearly 9 years of continuous service, and not all needed replacing – I just decided it would be better to replace them all at once rather than one-at-a-time as they became noisy.