~^Johnny^~ wrote:

On Sat, 04 Feb 2006 10:34:28 -0500, MC wrote:


We had to many time have phase
protection on the power to these units that if a problem happed as such
would kill power for all phases. The equipment can be costly and
therefore may not be worth it for residential use.


Nope. It's easily "hacked together" (for lack of a better term). Grab
an "artificial neutral", by connecting three equal resistors in a
WYE. Run the node of the WYE (the "artificial ground) through a
current sensor, to the real ground, or neutral. A preset unbalance
will develop a current offset from artificial neutral to real neutral
or ground, and trip the protective relay which will open the mag
(contactor)

A few bucks worth of Radio Shack parts, and a 16 year old nerd down
the street are all you need.

Or you could just buy one. All of our 3 phase units come with phase
protection consisting of a 2.5" x 2.5" card with very few components
mounted on it. Cost about 15 bucks apiece. How many do you need? BTW,
they will be marked up before you get them

Richard Perry