Symmetra LX 8KVA loud whistle/noise

[BillP]

This morning my Symmetra LX 8KVA started making a loud whistling noise but it is showing no faults or anything different then usual. Normally it makes fair amount of noise, but this one can be heard through 2 walls and down the hall, and its not the alarm.
I've run the self diagnostic which passes, and there last event was auto self-test 6 days ago.

Any input on where to start troubleshooting this would be greatly appreciated.

[BillP]

lol glad you are all set.

[BillP · Accepted solution]

hello..

i am going to assume you made sure you ruled out any other equipment making this noise? what i would guess, if it is actually the UPS, is maybe a power module. if you had redundancy, you could try pulling a module at a time to see if it stops when you remove any PM. if you do not have redundancy, the UPS would go into overload bypass though so if you are not sure if you have redundancy or not, you might want to verify that by checking the status menu on the UPS front display and see what it says. you can also check the network management card if its configured. you'd want at least N+1.

another idea is to try and put the UPS into maintenance bypass using the switch behind the UPS front cover to the right of the UPS powerview LCD, labeled as so. this would bypass the UPS inverters temporarily but keep the fans spinning on the power modules (which are the modules on the left side of the UPS labeled SYMP4KP. you could also try doing this to see if the noise stops.

before you touch it though, does anything ring a bell as far as adding some load the UPS, having a different load, removing some attached load, or installing any new parts?

if you have any questions before touching the UPS please let me know.

[BillP]

i am going to assume you made sure you ruled out any other equipment making this noise?

The UPS the only equipment in that room.

before you touch it though, does anything ring a bell as far as adding some load the UPS, having a different load, removing some attached load, or installing any new parts?

The noise started after I got in to the office this morning, and it can actually be heard from the lobby right now (the equipment room is down a short hall from the lobby), which isn't good.

what i would guess, if it is actually the UPS, is maybe a power module. if you had redundancy, you could try pulling a module at a time to see if it stops when you remove any PM. if you do not have redundancy, the UPS would go into overload bypass though so if you are not sure if you have redundancy or not, you might want to verify that by checking the status menu on the UPS front display and see what it says. you can also check the network management card if its configured. you'd want at least N+1.

another idea is to try and put the UPS into maintenance bypass using the switch behind the UPS front cover to the right of the UPS powerview LCD, labeled as so. this would bypass the UPS inverters temporarily but keep the fans spinning on the power modules (which are the modules on the left side of the UPS labeled SYMP4KP. you could also try doing this to see if the noise stops.

Its configured with 2 power modules and 3 battery modules, load at 40%, and fault tolerance is N+1.

What is the difference between the control panel activated bypass and the manual maintenance bypass?

[BillP]

well the bypass option on the LCD is called command bypass where as the switch is more of a physical bypass that you control by operating the breaker. when you do command bypass, the UPS checks to make sure it is OK to go (voltage/frequency in range, etc). i also found some more info:

The manual bypass mode provides a no break transfer of load from inverter to bypass, or in other words it is a make-before-break transfer. Exiting from manual bypass to inverter involves a transfer time of 2-5msec and there is no check of the line voltage or other characteristics. Please keep in mind that when returning from maintenance bypass the Symmetra enters automatic bypass momentarily before attempting to transition to the online state.

[BillP]

jparker wrote:

i am going to assume you made sure you ruled out any other equipment making this noise?

The UPS the only equipment in that room.

Scratch that, turns out someone installed and partly hidden a small budget UPS in the other corner of the room on a small phone system and it was making the noise. No idea it it was a fault alarm or not, but taken it out till someone admits to putting it there without tell me.

Thanks for the help, I actually would not have looked gone looking for a different source.