Ya' know, I'd like it better if they clearly stated that it was intended to be applied to a 3 phase load somewaht more clearly than: quote"Adds ground fault protection to heavy equipment powered through 3- or 4-wire circuits". Because if you go to look at the wiring diagrams, http://www.leviton.com/sections/prodinfo/newprod/npleadin.htm
, you will see that they only list : 30 Amp GFCI Wiring Diagram 3 - 2 Phase Circuits (120/240V Relay, 3-Pole),beyond which the pther diagrams call out 120, 208/240, or 120/140 volt circuits. I believe that they also erroneously call it "2 phase". The part of the heading on the web page that calls out Only for 3- and 4-Wire Systems That Include Grounded Neutral, and also depicts it in the wiring diagram, would lead me to believe that it is not listed for your installation since a 3 phase motor does not employ the system neutral. Additionally, where would you obtain the 120v control circuit from.
The current donought would appear to be a zero equence type so while it might work in theory, it probably wouldnt be listed.
As an aside, last year or so, I tried to buy one of the Leviton spa packs that you mentioned, and that do exist in the catalog. I was told by Leviton that if I wanted to purchase a large quantity of them, they would build them, but they didn't notmallr do a onesy or twosey sale. So I complained to the Leviton salesman, and he GAVE me the sample he had in his trunk. It works well.
[This message has been edited by US Coreman (edited 07-15-2003).]