Smart-UPS noise levels

[Anonymous user]

Hi,
I want to buy a Smart-UPS to use it with a video projector and an HTPC in my new home theater. I live in Europe and dedicated AV solutions from APC are not available here (wonder why??!!) The UPS will be placed in the viewing room and absolutely critical thing for me is the noise level it generates when online (I don't care about the noise when the UPS is on battery). I haven't had any UPSes before and have no experience with them so please answer on this:
1) Is there any noise (buzz, humm) when the UPS is online (not on battery or during charging) and the incoming AC is good (voltage and frequency are nornal) and no AVR correction in use. I am talking about normal operating conditions and don't want to count in any anomalies resulting from bad AC, wiring, interference. If there is any noise - how bothersome it is?
2) For example APC Smart-UPS 2200VA does have spec "Audible noise at 1 meter from surface of unit" rated at 45.00 dBA. That's a lot! But I am hoping this is under full load and on battery wih the fan working? What's interesting - the same spec for APC AV 1.5kVA S Type Power Conditioner with Battery Backup is 0.00 dBA and I can see this unit has a fan as well! I just don't get it.
3) I have read that the built-in fan kicks in when the UPS gets 40 degress Celsius or hotter. Can if happen if I use it under 50% load with room temperature under 25 degrees?
3) What is the switching time to battery in milliseconds after the AC power is off? Should I even care about it or I will be totally safe with a Smart-UPS?

Thanks a lot

[Anonymous user]

Sorry to resurrect an old thread, but I must disagree that the normal operating noise from a SmartUPS unit is acceptable for A/V use.

I have four SmartUPS 1000 units, and all of them emit a hum whenever they are connected to the utility power. My previous UPS (from another manufacturer) was totally silent, so I was rather disappointed that the APC units make such a loud noise during normal operation.

I would say that these units are too noisy for use in a domestic A/V environment.

[Anonymous user]

The SmartUPS isn't really designed for AV use. Older (early 90s or so?) APC UPS's used two transformers. One small one for charging and large main transformer for on-battery use.

To increase charging current, thus reduce charging time, newer units use the main transformer for charging. Main transformer is always energized, so the noise level and standby power use is substantially increased.

[BillP]

Hi,
Fan cooling is on during four normal, though in most cases infrequent, modes of operation. These modes are listed as follows:
- The fan is on whenever the UPS is operating on-battery. This also includes the automatic self-test which is run every 14 days for a couple of seconds.
- The fan comes on when the UPS's internal temperature exceeds 40°C. When cooled to below 35°C, the fan is shut off.
- The fan is on when the output load rises to above 75% of full rated load. When the load is reduced to below 70% of full rated load, the fan is shut off.
- The fan is on when the battery charger is delivering power subsequent to a utility outage.

Obviously this is only true if a fan is fittet into the UPS. The smallest 230V SmartUPS without a fan is a SUA1000i.

If a fan is fitted and none of the above conditions are true there is no noise coming out of a SmartUPS line-interactive.

A BR1000i does not have a fan, despite ventilation holes in the chassis.
A BR1500i has a fan. This fan comes on when the UPS runs on battery and if the load is > 650 W and the unit is in boost operation.

Any SURT will have a fan and those fans are running constantly as soon as the units are plugged in.

It would be the fan which creates most of the noise. Humming noises from the transformer might be present when the UPS runs on battery.

Switching time of a line-interactive SmartUPS is 2 - 4 ms. Any standard powersupply will be able to bridge that.

Hope this answer helps
Regards

[Anonymous user]

Many thanks Big3 for such a detailed answer. It's great to hear that Smart-UPSes do not hum or buz when fan is not working. However that leads to a conclusion that I should buy a higher capacity model (like 2200 VA) to be safe not to exceed the 75% load (fan kick in point). Am I right? In that case I wonder how is this possible?

[TheNotoriousKMP_apc]

Kobe,

It's not recommended you exceed 80% capacity on any UPS with a non-linear load. That will avoid a possible overload.

The same reasons for the fan kicking on would apply that were mentioned before.

[Anonymous user]

The Notorious K..
can you confirm that Smart-UPSes do not hum or buz at all (are totally silent) when not working on fan? Would be nice to get a confirmation from such a notorious poster like you 🙂

Thanks

[TheNotoriousKMP_apc · Accepted solution]

Kobe,

There is SOME audible noise, however, I can tell you that it can't be anything too straining on the ears. So long as any electromagentic issues have been addressed (which are rare in most cases), there is almost no noise coming from it.

I consistently use a SUA3000 here for training purposes and when online, there is minimal noise anywhere near the unit.

Other than the AVR relays kicking in (which will cause a hum for the duration of the relay being enabled), the only time the UPS should make any noticeable noise is when on battery or when the fan is on for the aforementioned reasons.

[Anonymous user]

Thanks guys,
I think I've got a good idea now.

Do you suggest additional surge protection besides the Smart-UPS? Is it recommended? Should it be before or after the UPS in the chain?

[TheNotoriousKMP_apc]

Kobe,

Since putting a surge protector upstream from a UPS (before the utility socket at the wall), would be highly inefficient with respect to power, you may want to look at an overall service panel surge.

The product information is here:

http://www.apc.com/products/family/index.cfm?id=174

[Anonymous user]

Kobe wrote:
Thanks guys,
I think I've got a good idea now.

Do you suggest additional surge protection besides the Smart-UPS? Is it recommended? Should it be before or after the UPS in the chain?

Putting a surge protector upstream of the UPS is not an issue at all, but its not a very good idea to do so downstream. However, it's perfectly fine to use a power strip or PDU downstream of the UPS to increase the number of outlets to accommodate wall warts and such.

my opinion may not reflect the official opinion of APC as I do not represent APC.

[Anonymous user]

Hi; I just purchased 3 refurbished Smart APC3000s. The fans on each one come on about every 2 minutes and stay on for about 1 minute. The noise is defeaning. The units have been plugged in for about a week, they are not on battery power and the load iis about 10%. I have set the sensitivity to low in case the power coming in was not clean that would keep switching it to battery power. Can any one please help. There is no reason for the fans to come on in my condition. The ambient temperature is about 68F. Thank you

[BillP]

can you please set the LCD menu on the front of the UPSs to "Advanced" from under the "Configuration" menu then go to "About" and tell us your UPS firmware. you should see four firmwares i think - CBL, UBL, COM, UPS.

thanks.