Kolpak Walk-in Freezer with Defrost Issue – Evaporator is Covered with Ice
After arriving at the location and speaking with client, I found the walk-in freezer temperature at approximately 50*F. Noticed that the evaporator coil was covered with ice, blocking air flow. Looks like a possible defrost issue. Went to the roof top and found condenser operational. Placed unit into defrost and check to see if defrost heaters were pulling amps. Clamp meter reading 6 amps during defrost. Data plate stated 6.3 heater amps. Allowed defrost to operate to melt ice from coil. After ice removal placed defrost timer at 3 pm. After 15 minutes of operation, timer clock did not move from the 3 pm position.
Determined that the timer gears or motor were faulty. Replaced defrost timer with new and tested operation. Set four defrosts per day, with 45 minutes of duration time. Also adjusted parameters on condenser controller. All other unit operations normal. Box temperature was 10*F before leaving and temp control was set to -10*F.
Client asked me to check out the walk-in cooler as well. He said it was making a loud noise. Found noise was due to a broken fan blade in the evaporator coil. Disconnected the power and pulled off the fan blade. Found the coils were fairly dirty. Sprayed the coils with no-rinse cleaner. Replaced fan blade and started system back up. Tested operation of unit. All components working normally. Box temperature was 41*F. Temperature set to cut-out at 35*F.
Check out Paragon Defrost Timer Manual