Welcome to the new Schneider Electric Community

It's your place to connect with experts and peers, get continuous support, and share knowledge.

  • Explore the new navigation for even easier access to your community.
  • Bookmark and use our new, easy-to-remember address (community.se.com).
  • Get ready for more content and an improved experience.

Contact SchneiderCommunity.Support@se.com if you have any questions.

Close
Invite a Co-worker
Send a co-worker an invite to the Exchange portal.Just enter their email address and we’ll connect them to register. After joining, they will belong to the same company.
Send Invite Cancel
84704members
354082posts

Back-UPS ES 750 buzz/hum noise?

APC UPS for Home and Office Forum

Schneider Electric support forum for our APC offers including Home Office UPS, Surge Protectors, UTS, software and services and associated products designed to share knowledge, installation, and configuration.

Solved
mmiller7_apc
Cadet
0 Likes
1
131

Back-UPS ES 750 buzz/hum noise?

This was originally posted on APC forums on 11/9/2011


I have a Back-UPS ES 750 and it's making an annoying buzz/whistle noise. It's not all the time but when it's there I can hear it loud enough that I can't sleep. My parents have an identical unit that makes zero noise. It's louder when charging (e.g. after a power outage or self test) and it's not the same whistle that happens when it's running on battery power -- this is when it's on AC Mains power. Aside from the annoying sound it seems to work fine and switches between battery and AC power normally.

Here's what I have connected:
-Laptop with 160W power supply
-Laptop with 90W power supply
-16" TV used as external monitor
-USB hub
-Radio charger
-Powered computer speakers
-Coax/Ethernet bridge
-WiFi print server
-Inkjet printer HP PhotoSmart 7260v

PowerChute says I'm pulling between 40 and 200 watts depending on whether it's running/charging my laptops or not. I've checked with my Kill-A-Watt meter and even if I add on the light, clock-radio, weather-radio, and desk lamp that are on the non-backup plugs I'm still only using about 300 Watts peak so it shouldn't be overloaded. I turned it off overnight and it's quiet now in the morning which seems odd as well. I thought it needed more air or something so I propped it up off the carpet using a large ceremic floor tile but that didn't make a difference.

Before someone complains about the printer, our other Back-UPS ES 750 we have has more connected (including 3 network adapters, a cable box, a mid-range desktop tower, inkjet all-in-one, and a second inkjet printer) and it never makes any noise and chugs along even during outages without a hickup.

Has anyone else had this problem with humming or whistling?


Accepted Solutions
voidstar_apc
Janeway
Janeway
0 Likes
0
132

Re: Back-UPS ES 750 buzz/hum noise?

This was originally posted on APC forums on 11/9/2011


You could try swapping your parent's BackUPS with your own and see if the noise follows the BackUPS. Sometimes electrical distortions on the power line causes the transformers in devices like the BackUPS to vibrate generating a noise. One person here mentioned tracing a similar issue back to a dimmer switch.

See Answer In Context

1 Reply 1
voidstar_apc
Janeway
Janeway
0 Likes
0
133

Re: Back-UPS ES 750 buzz/hum noise?

This was originally posted on APC forums on 11/9/2011


You could try swapping your parent's BackUPS with your own and see if the noise follows the BackUPS. Sometimes electrical distortions on the power line causes the transformers in devices like the BackUPS to vibrate generating a noise. One person here mentioned tracing a similar issue back to a dimmer switch.