Recently I wrote:

> We have a 220 VAC A2996A 1.3KVA UPS rackmounted with our 918.
> I thought I could fool the system and use the UPS to power some
> 110 VAC peripherals (like to system console).  To do this, I
> split the 220 voltage in a duplex receptacle by using only one
> leg of the 220.  If figured it like this:  hot-to-hot is 220,
> hot-to-neutral/ground is 110.  This works okay so long as the
> line power does not fail.  If the line power fails and the UPS
> kicks in, then something very interesting happens.  The hot-to-hot
> 220 circuit is okay, but now the hot-to-neutral/ground is also
> 220, instead of being 110!  Fortunately I put the peripherals on
> a surge suppressor which kicks out when the 220 appears on the line.
>
> Is this "normal" behavior for this UPS?  Should I just bite the
> bullet and buy another UPS for use with the peripherals?  Actually,
> I thought there would be a 110 VAC outlet on the UPS to at least
> power the system console, but there isn't.  Thanks for any help
> you can provide.
>

And Nick Demos responed with:

>Not sure this is the answer, but I had a
>similar problem in a house circuit where I thought I was going
>to ground.  It turned out that I was going to a DIFFERENT leg
>of the 220 circuit.  I would check your connections closely.

What I really meant to say is that when the system is on line power,
I can get 220 across two legs, and 110 from each leg to ground.  BUT,
when the UPS kicks in I lose the 110; that is, what used to 110
(the hot-to-neutral/ground) is now 220.  In fact, there is no way
to get 110 out of the UPS (at least as far as I can determine).  I've
tried each leg to ground and there is no 110.

Hope this clarifies the issue.

Jim Phillips                            Manager of Information Systems
E-Mail: [log in to unmask]      Therm-O-Link, Inc.
Phone: (330) 527-2124                   P. O. Box 285
  Fax: (330) 527-2123                   Garrettsville, Ohio  44231