I’ve heard good things about Liebert UPSs. No personal experience, however.
Salem Media Group Omaha
From: Gullikson, Brian F [mailto:firstname.lastname@example.org]
Sent: Saturday, August 12, 2017 3:33 PM To: CRTech Cc: Allard, Mark G Subject: RE: [CRTech] Liebert 6KVA UPS
We have a large building-wide Eaton UPS that was just installed a couple years ago. No strange noise or complaints from us! It works great! I think you just
have a lemon there! Mark Allard headed up the installation project for our current unit, and he may have more insight for you.
I've copied him here.
Brian Gullikson, CBRE 98.5 KTIS-FM | Faith 900 KTIS
Has anyone used a Liebert UPS in their facilities?
We have an EATON 6KVA unit and it introduces the most unbelievable noise into our audio plant.
Our electricians put an iso transformer on the output of it, which helped, but the transformer lives in our rack room and gets so hot you can't touch it. I had them come and bypass it last week. The room temperature
is much better, but the noise in the building is back.
This isn't ground loop noise. When the batteries are bypassed in the EATON unit, the noise goes away. It sounds like a squared wave/frying eggs type sound. Really bizarre.
The unit basically puts out a dirty AC wave. EATON sent a rep and he said the unit is running within specs.
Also, you can hear the same noise physically emanating from the unit. Sounds like bacon cooking. Sure enough, the same noise gets into our audio, especially mics.
We have an AoIP plant. No long runs of audio anywhere. Shielding doesn't fix it either. If you move audio cables around AC cords you can hear this crazy noise come and go.
Anything plugged into street power is immune to this. The UPS is a mess. FWIW, I didn't specify this unit when it was installed.
All of that so say, I'm not looking for troubleshooting measures. I just want to go with Liebert and wanted to know if anyone has any success.