SMX1500RMI2U hissing noise - normal?

[roobo_apc]

Hi,

I have a brand new SMX1500RMI2U (Australian 230 volt version). It's silent when just plugged in, but makes a hissing noise when turned on. I originally thought it was a leaking battery, but after listening a while it seems more like an electronic sound. I've attached a WAV with the UPS in the off state then being turned on and going through it's self test with no external load. I've tested with varying loads and in 2 premises in different suburbs to rule out any local electrical noise, the hiss is pretty much always there.

I also bought a SMT1500I a week earlier and it's great. Other than the faintest fan noise if you hold your ear against the fan grill, it's inaudible unless on battery. The SMX will eventually go in a rack, but right now it's in the tower configuration in an office environment, and is loud enough to be annoying.

On another note, the physical build quality of the SMX is a bit disappointing. Some rivet heads are skewed and don't sit flush with the case, as are a couple of screws.

Are these issues worthy of an RMA, or is this what I should expect?

[BillP]

Hmm. I am still waiting on someone from our Smart-UPS team to follow up with me on disabling the green mode via the LCD for this model. I know you can do it for certain UPS types via a UPS Network Management Card but it all depends on if the UPS supports it. It is a holiday here today so I will check tomorrow. But yes, it'd be a firmware limitation potentially on the UPS and if the UPS supports it, it may only support it via one way or another - LCD vs. PCBE.

Let me report back tomorrow hopefully.

[BillP]

Hi Angela.  I'm feeling dumb as I can't find any way to toggle green mode on and off on either my 3000 or my 1500RM2U via the NMC.  Can you please point me in the right direction?  Thank you.

[BillP]

On the LCD, you'd definitely need to make sure you set your menu to "advanced mode" to be able to see it anywhere. In the NMC, you'll need at least v6.0.6 sumx or higher to see this, assuming the UPS supports it.

[BillP]

The NMC is on v6.1.1 and the UPS itself is a SMX1500RM2U (SKU).  I don't see it via the NMC so maybe it isn't available.  On the "Home" screen of the NMC interface, it says "No Alarms Present" and that the UPS is in the green mode.  Must be available only from the LCD panel which I will try in a bit.

[BillP]

I am going to see if I can clarify or get a chart showing which models of UPSs support this (and what firmware) and from where (LCD, NMC, PCBE) before I keep suggesting to check it and it's not there and we waste time. I am thinking this UPS does not support it if you do not see it anywhere in the NMC.

[BillP]

OK, I did learn one thing. I tracked down someone who could check this model (since I don't have one) and we don't see it via the display. But, it is NOT all or nothing meaning the NMC could support it even if the LCD does not. So, we can still check the NMC interface under the Configuration->Power settings menu. I tracked down an SMX3000 that does support it and it is there. They are slow to support this I think because 99% of the time, the user should not have to touch this setting. I also found you can disable green mode effectively if you discharge the UPS slightly.

[roobo_apc]

I also found you can disable green mode effectively if you discharge the UPS slightly.

I was unable to replicate this with my SMX1500RMI2U RMA replacement unit. Going to battery, discharging down to 55%, then going back on utility power goes immediately to Online (Green Mode).

The hissing noise stays constant while on utility power at 0, 60, 500 and 730 watts. It does get slightly louder when on battery, but other than that doesn't seem to vary with load. I'm probably going to return this unit for a refund unless a 2nd RMA is likely to resolve it. I'm sure it wouldn't even be noticed in a typical server rack, but it's too distracting in a normal office environment

[roobo_apc]

Hi,

I have a brand new SMX1500RMI2U (Australian 230 volt version). It's silent when just plugged in, but makes a hissing noise when turned on. I originally thought it was a leaking battery, but after listening a while it seems more like an electronic sound. I've attached a WAV with the UPS in the off state then being turned on and going through it's self test with no external load. I've tested with varying loads and in 2 premises in different suburbs to rule out any local electrical noise, the hiss is pretty much always there.

I also bought a SMT1500I a week earlier and it's great. Other than the faintest fan noise if you hold your ear against the fan grill, it's inaudible unless on battery. The SMX will eventually go in a rack, but right now it's in the tower configuration in an office environment, and is loud enough to be annoying.

On another note, the physical build quality of the SMX is a bit disappointing. Some rivet heads are skewed and don't sit flush with the case, as are a couple of screws.

Are these issues worthy of an RMA, or is this what I should expect?

[BillP]

This is not normal for any UPS. I have one of these (120V) on my desk and you cannot even tell it is on, like you said, besides maybe for the fan or when it is on battery it hums.

I suggest that you proceed with asking your local technical support for an RMA and provide the sound clip because I think that says it it all (and helps rule out any differences of opinion).

[BillP]

I have one of these and mine has this noise.  The noise is very directional in nature and it is electronic noise of some sort.  I have this unit in my A/V room and would notice it whenever I walked by it.  I just moved it out of the way behind a rack of equipment and it doesn't bother me any more.  I think  it has to do with some low level coil whine in one of the switching power supplies.

Angela, if mine is not normal do you think I need to initiate an RMA?

[BillP]

What I heard in the sound clip is not anything I've ever heard from my UPS or any of these type we have in our lab (with our without load) so if it is the same noise, it isn't supposed to be there. I do think that you should get an RMA as to not have to worry about it.

[smargh_apc]

Last year I had an SMX750I which had this problem. The subsequent next two (I think...) RMAs also had different levels of this "fast ticking" noise. It was later RMAd with a different non-SMX model which didn't have the noise.

A few months after, I took a risk buying an SMX1000I which has been absolutely flawless. So, I always assumed it was a design "problem" specific to the SMX750I - the units worked perfectly aside from the mildly annoying ticking noise. I'm hesitant to call it a problem, because it could be designed perfectly well but just need tweaking - I have no idea because I know very little about electronics.

Angela: if you're interested, here's a video which I gave to Support at the time: YouTube

[roobo_apc]

Thanks Angela, I've started the RMA process.

@smargh, although my unit does have a similar ticking noise, it's much softer than the hissing noise. The ticking is nowhere near as annoying (or loud) as the hiss. My sound clip overstates the volume of the ticking, but it's the best I could get with my mobile phone mic.

[roobo_apc]

The RMA replacement showed up today, and it exhibits exactly the same noise . I don't know what to think now. At least the rivets are straight on this one.

[BillP]

So you said you tried two different locations originally. Varying loads - does that mean percentage wise or different types (computer, lamp, network device, etc)?

I had someone else listen to it that supports Smart-UPS on a regular basis and he said it's not anything that affect the functionality or life expectancy of the UPS from the sounds of it. But he also suggested disabling green mode on the UPS (which may require you to send the menu to advanced mode) since disabling that will change the power path inside of the unit and may cause the noise to change.

[roobo_apc]

My tests were 0 watts, 60

[BillP]

There should be a configuration menu on the front LCD of the UPS. In there, I think it has menu mode - standard or advanced. You'd want to change it to advanced and then review the new options available, still under configuration. I don't have one right in front of me to check so I am going by my memory. It will be where all of the other power related things are configurable like sensitivity, etc.

Also, if you still don't see it, let me know what UPS firmware you have under About menu via the front LCD for this new UPS.

[roobo_apc]

Thanks Angela. It's already in the advanced menu mode, and I don't see anything about green mode. The firmware details from the About menu are:

UPS Firmware 1: UPS 09.1

UPS Firmware 2: MCU 09.1

UPS Firmware 3: UBL 06.9

UPS Firmware 4: MBL 06.0

[LeJPL_apc]

Hi,

I bought  two new  SMX1000I units(one for my home studio and one for my brothers PC) earlier this year from the TradeUPS  program  and they  make  the  same annoying high frequency  hissing/buzzing noise when turned on.  Yesterday  I  received  replacement  units from APC  and  they  make  the  same  noise  also, so  I  have  four  units  waiting  for  return.  These  units  are  too  noisy  for home usage.   

Geoff  are  you  still  happy  with  the  SMT1500I?  I'm  hoping  to  get two of those as a replacement units.  

[roobo_apc]

Yes, I'm still happy with the SMT1500I. It's so close to me I can reach down and touch it without moving my chair. Can't hear a thing.

The replacement SMX1500RMI2U is sitting in a fully enclosed rack a couple metres away. I can still hear the hissing over a 4U server in the same rack (admittedly I did put some effort into quietening the fans on the server).

Based on the 2 units I've seen, I can't recommend the SMX1500RMI2U if you're going to be in the same room as it. It's not deafening, but it's the sort of irritating sound that's hard to ignore.

[LeJPL_apc]

Thanks, that's good to hear. I hope APC/Schneider Electric hears/sees these problems, because there are plenty of people looking for a quiet tower/rack sine wave UPS for their home workstation/server.

[Fintan_apc]

Hi 

I have just taken delivery of a SMX750i and have the same issue, did any of you ever get a solution to this?

Kind regards

Fintan

[konstheo_apc · Accepted solution]

Bought an SMX1000i and has *exactly* the same issue as the OP.

Had it RMA-ed and the new product exhibits the same annoying sound.

APC please, can't we really fix this somehow?

(or keep RMA-ing until receiving a flawless unit? lol !!)