John D. Alleyn-Day writes:

>Clever idea, Jim, to get the neutral from the ground - just don't let your
>local electrical inspector find out!  You are defeating an important safety
>feature and, under certain circumstances, you can back-feed 110V on the
>ground connection.

Uhhhhhhh. . . what I'm doing is splitting the two hot legs and using the
neutral (not ground).  There are three wires in the 220 outlet from the
UPS.  Normally (line power) I get 220 between the two hots, and 110 between
either hot and the neutral.  So I just split the two hots and got my 110
to run the console.  However, since the ground is bonded to the neutral
somewhere down the line (usually at the main box), it's the same result
when you go from either hot to ground.  But, just to be safe, I ran a
four-wire cable to my 110 outlet: the two 220 hots, the 220 neutral, and
a ground (which goes directly to the rack frame).

<snip>

>You said that you had measured 220V from one live wire to ground.   I'll
>bet you got zero volts to the other leg (because it's grounded).

Nope.  When the UPS is running, I get 220 between the two hots, and 220
between either hot and the neutral.

>Yes, you can definitely solve this problem with a step-down transformer.
>However, since a 110V UPS can be had for under $100 these days, I'd just
>buy one and plug it in for your 110V equipment.  Quick and easy, and should
>cost less than a step-down transformer.

My point is: Since HP provides the PowerTrust UPS to allow you to perform
an orderly shutdown of the system in the event of a power loss, and since
you can't perform an orderly shutdown without a system console, why
doesn't the UPS provide at least one 110 outlet for the system console?

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