Silent Sine Wave Output UPS

[Mike177]

Hello, I recently purchased a SRV1KI (APC Easy UPS On-Line SRV 1000VA 230V) and the fan is always running, regardless of battery charge and/or load.

Speaking with support, they confirmed that the fan on the SRV models never turns off, and the noise is unbearable in a home environment.

I want to replace it with another model that turns off the fan when the battery is full and the load is light. Would a SMT series UPS be silent, and at what power? Can I get a SMT1000IC or do I need a smaller SMT750IC for fanless operation?

Thank you very much!

[BillP · Accepted solution]

@Mike177 

I have a SMT1000C sitting on my desk and I rarely of ever hear the fan run.  I also have a SMT1500C and I do not hear its fan run. 

[Mike177]

Thank you very much, I recently returned the SRV1KI and received the SMT1000IC and it is absolutely silent (only some minor humming noise that I can hear if I put my ear next to it)

[paolo]

I had a similar problem..

I bought a SRT1000 with NIC. Super nice product. 

Unfortunately i was not aware of the always running fan until i mounted in my Home Teather room..

Since i like the rack mount option, is there any double conversion, rack mounting but silent UPS from Schneider..? 

Thank you for your help in my research...

Best regards from Italy.

Paul.

[Teken]

Short Answer: No

Long Answer: The two stage fan is always on do to the fact the system is always inverting and providing clean regulated pure sine wave AC power.

The options are to purchase another brand & model UPS. Replace the 24 VDC (two pin) fan with a quieter unit that provides the same static pressure as the OEM one and void any factory warranty.

If the unit is not in warranty it doesn’t really matter. If you decide to go down this path invest in a high quality fan!

Should the cheap fan die unexpectedly the system will begin to heat up and the service life of the hardware will drop significantly.

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[paolo]

First of all, thank you for your super useful answer.

I've bought from a UK IT reseller as a "as a new" unit, so for now, I may not try to go for a 24 Volt Noctua fan. As far as you know, is there any Schneider rack-mountable unit like the afore-mentioned SMT1000IC? 

I need only to give energy for roughly 30 minutes to some Unifi devices (G5 and G6 Cameras, Cloud Key gen2, POE switches, modem) for a total of roughly 180 VA...so may be a double conversion unit is a little overkill..  

Thank you for your reply.

Paolo.

[Teken]

Both the SMT & SMX Series are (Line Interactive) pure sine wave systems which have no fan noise and only come on during the following conditions:

Loss of AC Power, charging, over temperature internal / battery, etc

Both use the same dual stage cooling mechanism but neither turn on unless the conditions listed up above are seen.

They also use a 2 pin (24 VDC) fan as the SRT Series. Should you consider replacing the fan the plug will need to be replaced or reused with any new fan.

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