On Wed, 29 Sep 2010 13:41:14 -0500, "Pete C."
wrote:


Tim Wescott wrote:

On 09/29/2010 09:55 AM, Karl Townsend wrote:


Is the part labeled 1 an isolation transformer? If so, should DC- be
grounded?

Most likely it's a three-phase step up or down transformer. It looks a
bit small compared to the diode array, but what do I know? If the leads
on the left don't show any conductance to the leads on the right it
isolates as well as any step-up or -down.

It may be a 1:1 isolation transformer which may help explain it's
relatively small size. If it were a step-up or step-down I expect there
would be a few voltage taps.

It looks more like a 3-phase line reactor. For example:
http://www.transcoil.com/Products/InputSide/KLR.htm

--
Ned Simmons