Found a 404a walk-in freezer with ice build up thru the evap to the fans. After de-icing, I found the compressor running during defrost cycle. The suction pressure stayed at (or about) 20psig and of course wouldn't go out on low pressure. I beleive the low/high pressure control is good. The unit is cooling great but I'm assuming the ice built up over a long time. Monday I'll really get to work on it (no overtime for me) and plan to check the soleniod(which did de-energize) and the compressor valves. How, exactly, is my question. The compressor, I plan on front seating valve at the receiver and watch my low side. The soleniod (I don't know), temp. difference? Any help would be great.
