Gita call on Thursday cooler iced up. The customer shut the condensing unit down to deice evap coil. I arrived on site to find some ice in the center of the coil along with several paper towels plugging the evap. Removed the towels and started the unit up. Box was 50. Degrees r404a 225head 63 suction, about 75 degree ambient.
Watched the box for a bit, evap is good and clean, sight glass is clear, thermostat cycling the unit ok unit pumps down using t-stat and holds great. Unit has a time clock set for 45 defrost at night. This box located outdoors and from8am to 4pm is as high traffic as anything. They are latterly in and out every minute .
I added two defrosts so ther are 3 a day there not evenly spaced due to the large demand on the box I am set at 1am 7am and 2 pm for defrosts.
I also changed out the thermostat to an ranco etc. I am gonna return to the site in the am and check sh on the txv. The ice pattern to me says bad txv. This is a Trenton per assembled evap with smart speed. So when the testator is satisfied the evap fans run at half speed vs when the stat is calling at full speed.