Noisy fan on SMT1500

[BillP]

I recently bought an SMT1500 UPS. The fan is noisy - it runs for about 5 minutes, shuts off for about 5 seconds, and repeats. has anyone experienced this? I know the SMT1500 has a 2-speed fan, but this fan seems to be on high speed all the time. I manually put the UPS on battery and the fan speed did not change.

[BillP]

I recently bought an SMT1500 UPS. The fan is noisy - it runs for about 5 minutes, shuts off for about 5 seconds, and repeats. has anyone experienced this? I know the SMT1500 has a 2-speed fan, but this fan seems to be on high speed all the time. I manually put the UPS on battery and the fan speed did not change.

[Techie_apc]

The UPS fan is used for internal circuit cooling. There is no need to worry about the fan operation of this unit.

[Anonymous user]

APC recommend a 65 to 70 degree environment as well as adequate room to ventilate. For stand-alone units, we recommend at least four inches on all sides (except the bottom) for adequate airflow around the unit.

Check you are having above temperature status on your location.

[Anonymous user]

Also, fan speed appears to be independent of total load and battery charge level. At 100% battery, with only 8% load, the unit sounds like a vaccuum cleaner.

Message was edited by: Liam

[Anonymous user]

Because the fan is loud. My main computer is in my media room, and the unit makes a lot of noise. Significantly louder than my tower and server combined. The UPS reports temps below 30 degrees C, so there should be no reason to run a fan at high speed. This might be a deal-breaker.

[Anonymous user]

I'm experiencing the same thing with an SMT1500. Fan on always, except for 5 second intervals. Is this normal? Temperature does not appear to be an issue.

[BillP]

I'm honestly confused why there's reason to be concerned over the fan's operation. It's there to keep the unit cool, so yes, it will be on whenever it needs to be. I'd be more worried if it wasn't on... Computers & related equipment don't like to be hot, and neither do batteries. Higher temps would reduce the life expectancy for both.

[BillP]

I have to agree with Liam. I just purchased an SMT1500 to replace my Back-UPS 1500LCD unit. I thought this would be a great upgrade. The fan on the Back-UPS unit never ran at all unless the unit was running on battery. Also, directly from the APC literature:

With the high efficiency ‘green’ mode the UPS runs cooler resulting in less degradation of the battery.

Sounds great, this should run cooler than my older unit. The status page on the SMT1500 shows the unit running constantly at 70F, so this must be point when the fan shifts from low to high. I don't know how this unit it so much "greener" when the fan runs all the time.

I was considering getting a second one of these for my media room equipment, but the fan is just too noisy. I currently have an old Smart-UPS 1000 in there now, but it is over 6 years old. I will be looking at other manufacturers for a replacement.

Among other annoyances with the SMT1500 versus my other Back-UPS unit is that the LCD display always reverts back to load/charge screen, instead of staying on the last screen displayed. I like to see the remaining run time more than anything else, as we have frequent power outages.

I hope APC can come up with a firmware update that will address these issues, otherwise this is the last Smart-UPS I see myself purchasing.

[Anonymous user]

It's unfortunate to see that others are having the same problem. I was hoping it was just my unit (which is my second since the first one was DOA). If the firmware isn't fixed or the fan isn't replaceable, I have to imagine this will limit the number of potential buyers, since not everyone uses a UPS in a noisy sever room or a warehouse. Does APC offer a 1000W UPS that would be media room friendly?

[BillP]

There's the AV units... http://www.apc.com/products/family/index.cfm?id=310

[J10BLK|http://www.apc.com/products/resource/include/techspec_index.cfm?base_sku=J10BLK] has step-approximated sine wave so the [S10BLK|http://www.apc.com/products/resource/include/techspec_index.cfm?base_sku=S10BLK] would be the Smart-UPS equivalent. Only available through resellers, though they're a LOT quieter.

[Anonymous user]

I talked to an APC sales guy who said that the fan speed on the SMT units definitely are controlled by the unit's condition (e.g. operating mode or temperature) and does not always run at a constant high speed. Numerous reports and product reviews by users seem to go against this, and I know that sales guys will say almost anything to make a sale, so it's a little disappointing that APC sales staff doesn't know their products better but maybe this is in fact a bug that will be fixed.

Heat in UPSes is understandably a large contributing factor to early failure and shortened battery longevity, but hopefully APC understands that non-RM units are often used in quieter office/home environments. Like many posters here, I am planning on getting a SMT1500 for home office use, but a constantly blaring 80mm fan would be horrible. Hopefully they'll also consider larger fans in the future, whose lower RPM required for the same CFM results in a quieter and lower pitched hum.

[BillP]

45% on the SMT1500 is about 450w, and the S10 can handle 700, so that should be fine. You'd probably get a bit less runtime though (about 20m on the S10 vs about 25m on the SMT). Other differences... number of outlets (12 vs 8), S10 handles bigger overloads longer, no smart slot, more AV specific protection (data cable surge protection), LCD screen for config & settings... though it only works with PCPE - not business edition. You can setup power-on delays for 2 outlet groups... Those are the major differences I can think of.

[Anonymous user]

Thanks for the update, falcon. To those who have SMT1500s, do your units have manufacturing dates on them? We might be able to track down noisy units that way.

[BillP]

I took Techie's advise and contacted customer support. The unit was replaced. The fan on the replacement unit still has the same silly duty cycle - 5 minutes on 5 seconds off regardless of UPS temperature - but it is definitely quieter - so far - (I don't hear it starting up and shutting down from across the room as the previous one did and I have to get to within a couple of feet to hear it running). I don't think this completely resolves the issue of the noisy fan, but the replacement unit I got could have come from a different manufacturing batch with a fan from a different manufacturer or with a lower CFM rating. It's something APC should address as I expect these units are mostly used as "deskside" units in relatively quiet environments as opposed to being in a server room.

[BillP]

The manufacture date on the current unit is 12/4/2009, which coincidentally is also the date the battery was replaced, according to the "UPS Information" summary. I received the current unit on 3/10/2010.

[Anonymous user]

I just received an SMT1000 and it's having the same issue. It was purchased for use attached to an audio workstation. When the fan is on low speed it's fine... but once the fan kicks into high gear (15 minutes at 62% load or 70 minutes at 43% load - we kept disconnecting things to see if was load related) it does the same on forever, off for a few seconds routine. It never goes back to silent running.

Even with everything powered off (the unit itself too) - if it stays plugged into the mains the fan speed is on high with those 5 second breaks.

APC is shipping out a replacement but after reading these posts I fear that I have just purchased a unit that won't meet my needs and certainly doesn't work as advertised.

APC support was amazing however, so if didn't need a quiet running unit I'd definitely support them!

Message was edited by: dialing_wand

[Anonymous user]

I am experiencing the same problem. I am posting this message just in case somebody from APC is monitoring these discussions - the noisy fan in the SMT1500 unit is a problem that affects apparently a lot of customers.

[Anonymous user]

This thread has me depressed. After years with ancient SU1250's, I finally purchased a shiny SMT1500, with a network card. Get it all plugged in and after 30 minutes, the fan kicks in.

And stays on. Off for a few seconds, and then ON AGAIN. In a room with 6 computers, a switch, a laser, etc., easily 20+ fans, the fan in the APC is twice as loud. Noticeably loud. Driving me crazy loud. And the fact it shuts off after a few minutes and then starts right back up again is even worse. It just makes you realize how loud the fan is.

The fans in my old SU1250's and SU400 never run unless there's been a power event.

Reading through the internal data logs via the network card web interface shows the internal temps at ~77F. Using an infrared thermometer, and reading around the UPS at various points, that's probably close. (Although the external probe only reads 69F. Ambient is ~75F.)

UPS was silent until I put some load on it. About 15% at this time. The temperature slowly climbed up to ~85F, and that's about when I noticed the fan kicking in. Temp immediately dropped to ~77F, and has stayed there, with the running fan.

Does anyone know what the fan speed to temperature profile is? At what temp should the fan drop to lower speed?

Does the efficiency load have anything to do with it? At 15% load, the front panel is showing 87% efficiency. About right based on the published charts. I'll be adding servers and increasing load to 50%+, and supposedly mid-90's efficiency. Will that reduce internal load and temps? And hopefully get the fan off?

Is it possible to adjust the temp the fan turns on at? Maybe tweak it up a few degrees?

[Anonymous user]

These are brand new products, and hopefully they can release a firmware update to control the fan speeds with a little more grace. Now that the product is shipping I doubt it can be redesigned with larger fans, but they can move the same amount of air at lower spindle speeds for a low pitched hum that tends to be less annoying. Also, using more open fan grille designs tends to reduce air turbulence and therefore noise. Again, I understand if these techniques can't be implemented now.

This issue is obviously a big concern to many customers. Again, cool UPSes last longer and keep batteries happier so I understand what they're going for, but there should be a happy medium between bloated SLA batteries and blasted eardrums.

P.S. I'm actually in the market for a new 1500VA unit but I'd like a more reasonable fan control system than the current one. At this point my best option is to go with a refurbished SUA1500. More primitive UI, less efficient, but at least it'd be quiet. I'm only one datapoint, but small vocal groups tend to represent larger silent ones. A better cooling system will undoubtedly result in more sales. Please consider implementing one, or allowing users to implement an aftermarket solution that will not void the warranty (unlikely, I know).

[Anonymous user]

Same problem with the SMT1000. Apparently the noisy fans run on a timer or schedule that has nothing to do with actual load.

[BillP]

You would think that they would put more planning into a unit like this with a pretty big pricetag. When you're buying one of these units the last thing you put into consideration is the fan is like a vacuum cleaner from the 90s.

This isn't exactly helpful for myself either, I am trying to find good solution for a longer battery time sinewave unit. Somewhere in the 1300va to 1500va bracket. Within $400-500. And this is the only unit from the site I make purchases with that they have available in this bracket with sinewave compatibility without rack mount. This is for a Home environment too. It's great to hear so many issues with this revised unit. It really is, because, it sets me back. Time is wasting and only because APC released an inferior revision.

[Anonymous user]

clarkson wrote:
Thank you to everyone who has posted on this topic; your feedback is invaluable. 🙂 These issues have been brought to the attention of the appropriate group at APC and there are changes in the works to make future units better.

While I imagine that's great for new customers that does little for those of us burdened with units that do not work as advertised.

Please fix units that need to be used in Quiet environments. That won't be everyone. But for the few for whom it matters, a priceless statement of intent to current and future customers.

[Anonymous user]

I had to return my unit due to the noise level, but I'd consider buying another one if the fan settings are fixed. Please keep us updated as to any firmware changes. Thanks.

[BillP]

Really though, what good is that to the ones who already bought this crap expecting it to be an UPS Unit, not a vacuum. If you ask me APC was better off with the old unit. It at least wasn't a vacuum.

[Anonymous user · Accepted solution]

While I appreciate that these issues have been brought to the attention of APC for future product correction, this does not however help those of us who purchased the current product. If APC is currently looking to the future to "make future units better", than I would hope they would issue a firmware update for the current units in the field. When I purchased this unit I did not sign on as a "beta tester" for APC products. If a firmware update is not possible, then at the least offer those of us with a "defective unit" a replacement and I will be glad to return my current product. Thank you.