APC Symmetra RM Fan Replacement

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.

3 Responses to “APC Symmetra RM Fan Replacement

  • 1
    Terri’s Random Ramblings » APC Symmetra RM Front Panel Battery Replacement
    April 22nd, 2011 22:15

    […] the unit – see my earlier post – and pro-actively replacing all the fans – see this post, I powered the unit […]

  • 2
    June 29th, 2011 14:35

    Hi Terri,

    You wrote:

    “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.”

    This is absolutely false. The Symmetra takes no action based on system fan status other than the obvious System Fan Fault from the fan’s built-in tach signal.

    It’s probably not a bad idea to engage the system’s maintenance bypass switch on the rear of the UPS during system fan replacement. While extremely unlikely, I suppose you could have a miswired fan or some other issue that may irritate the Main Intelligence Module during the swap. Again, this is highly unlikely.

    If performing this service while the UPS is energized (in any operational state), be absolutely sure not to reach into the UPS — especially to the right of the fan bay where the NEMA/IEC outlets are. There are bare electrical connections that could shock you.

    Usually, if the UPS is installed in a temperature controlled environment (< 80F / 25C), system fan failure on this UPS is not an issue that requires immediate intervention. You can always monitor the temperature of the Intelligence module via the provided Network Management Card to see if it is increasing.

    Again, the UPS takes NO Action based on system fan state (beyond sounding the alarm). It will not go to bypass, shut down, or do anything other than continue operating as before when the fan stops or is disconnected.

  • 3
    Terri Kennedy
    June 29th, 2011 22:50

    @atptourfan – You are correct. At least with recent versions of the Intelligence Module firmware, the only thing that happens is that the system logs “System Fan Fault” and “Base Module Fan Failed”.

    My recollection (from some time ago, on a different Symmetra RM with much older firmware) is that the UPS did shut down. Perhaps my memory is incorrect, or there was some transient when unplugging the fan that confused the Intelligence Module.

    I agree completely with your advice to be careful to not touch anything inside the UPS other than the fan connector when swapping the fan (or, indeed, when performing any procedure not covered in the normal APC user manuals).

    In my related post on replacing the batteries in the SYBT2 modules (rather than simply replacing the whole SYBT2), I did mention “this can kill you”. That certainly bears repeating here.

    Thanks for your comments!

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