Contact US

Log In

Come Join Us!

Are you a
Computer / IT professional?
Join Tek-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Tek-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

UPS Power Question

UPS Power Question

UPS Power Question


      I have an AT&T 2 line corded phone with caller id that is pluged into a Cyberpower 1250AVR UPS (battery outlet) and if I put the UPS on battery power the phone gives me a "powerfail" on the screen as if it was just pluged into a normal outlet. Does anyone know what could be causing this and how it can be fixed. I do know that the transformer 120V/12V ratio and the phone is getting 12VAC not 12VDC

RE: UPS Power Question

Your phone is sensing the momentary drop in power as the UPS switches over from line to battery power. To avoide this you'd need to use a 'Full Floating' UPS - where the power is always being generated from the battery. I had to use one of those many years ago in a situation in a lumber mill where BIG motors running saws were always generating spikes that caused surge protectors to cut voltage for too long, and regular UPS's caused exactly the problem you're having with switchover gaps.  If the phone will work on 12V DC, you could put it on it's own small 12v battery and let the battery have a float charge.

Fred Wagner


Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Tek-Tips Forums free from inappropriate posts.
The Tek-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Tek-Tips forums is a member-only feature.

Click Here to join Tek-Tips and talk with other members! Already a Member? Login

Close Box

Join Tek-Tips® Today!

Join your peers on the Internet's largest technical computer professional community.
It's easy to join and it's free.

Here's Why Members Love Tek-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close