I'm new to this forum and prefer to watch and read before speaking. I tried several searches on my question and found nothing. Perhaps I didn't search the archives correctly.
Does using only two legs of 3 phase 220v for a 220/24 volt transformer prouduce poor and erratic 24v controls system power? Over the years I've seen this done I thought these systems went through a lot more contactor, relay, defrost conrol, and various other control problems. I've thought these systems had a lot more debris (left behind boxes, paper work and old components) and scars (re-mounting and rig mounting of components) left over by previous service inside these units after several transformer, relay, pressure switches, defrost control board replacements, etc. The service call would be poor or no heating/cooling. These units often had marginal control voltage; 18v - 24v at best and some days the main contactor would hum but not close with a control voltage of 11v - 18v. The units often have been serviced for the same kind of problem for years. Many others have replaced that "weak" contactor, "weak" transformer, or even added a small relay to power up the regular contactor solinoid. Every time I ran a neutral wire for a regular 110v/24v transformer and used one leg of the 3 phase 220v, I got good control voltage (27v - 29v) to the controls while under full load. Usually no more control system erratic problems and no more frequent control component failures. I will say more after a few replies come back. Thanks for the forum and allowing me access to it. james