Follett Freezer Temp is High – Under Counter REF5 / 00926626
Customer complaining that the Follett Freezer temp is high and has been for a few days. Found the unit temperature at 50*F. Checked all components and found they were operating normally. Installed my stubby gauges to check refrigerant pressures and found the suction pressures lower than normal. Unit discharge line and condenser were barely warm to the touch. Determined that unit was low on charge and therefore must have a leak. Returned with service gauges and nitrogen then pressured system to 125 psig. Searched for leaked using my leak detector. Unable to locate any solid detections. Doubled checked with leak bubbles and still unable to locate any leaks. Bled off nitrogen and pulled a quick vacuum. Recharged system with refrigerant per weight on data tag. Added leak dye to system. Informed client of leak issue and that we would return in a couple of weeks from now to allow leak dye to circulate and hopefully help us pin point where leak is in the system. Returned to the location and started search for leak dye. Found a little dye underneath evaporator coil. Called factory and checked the units warranty status and part availability. Checked unit charge and pressures looked normal. No need to add any additional refrigerant. Spoke with customer about findings and quoted repair. Customer said he would call us to make repair if approval was given. Unit is currently operational and temperature was at -3*F before leaving.
For additional information on this use click on the PDF: Follett Freezer Service Manual
Kolpak Walk-in Freezer not Getting Below 25*F
Found box temperature above 30*F. Evaporator fans were not running and the liquid line solenoid was buzzing, indicating it was getting power and should be allowing for refrigeration to the evaporator. Went outside to check the condenser and found it running. After further investigation, found the unit’s suction pressure was extremely low. Checked the low pressure control and saw that it was set to cut out at 15 psig, however the suction pressure was below 10 psig. Switched off the unit at the disconnect and noticed oil along the liquid line. Found the copper line had rubbed on the metal framing and had worn a hole creating a leak. Pumped the unit down via the receiver king valve and grabbed the turbo torch. Patched the hole with solder and replaced the liquid line drier. Removed the old low pressure control and replaced it with a new peanut style control. Pressured system and checked for leaks. Pressure held and was unable to locate any leaks. Pulled a vacuum and charged the system with virgin R404a. Turned the disconnect back on to test operation. Continued to charge the system until the sight glass was full and superheat was above 5*F. Pumped down the system once more to be sure the low pressure control was working correctly. Unit turned off at 13 psig. Also insulated a portion of the suction line to prevent sweat from dripping onto electrical box. Went back inside box and found evaporator fans running and box temperature at 18*F and dropping. Confirmed door thermometer was calibrated correctly and set the thermostat to 0*F. Explained my findings to the customer and recommended the evaporator be replaced because the fins were deteriorating. Checked the box temperature once more before leaving and it read 10*F on door thermometer.
To learn more about Kolpak click on the PDF: Kolpak Refrigeration Manual
True T49 Cooler Troubleshooting – Leaking at Evaporator
Arrived to find the box temperature at 60*F. Check temperature control and it checked out fine. Pulled off the front grille and found the discharge line was not hot. Checked the amps on the compressor, it was pulling 4.5 amps, which was lower than normal. These were indications that the unit was probably low on refrigerant. The refrigerant system is sealed from factory and did not have any service access valves. Installed bolt on access valves to the high side and low side of the system. Checked pressures with stubby gauges to read pressures. The suction pressure was in a vacuum and the high side pressure was very low. Added 100 psig of nitrogen into system in an attempt locate the leak. Heard nitrogen leaking at evaporator u-bend. Confirmed leak and location with bubbles. Purged the nitrogen charge and pulled out my turbo torch. Removed the bolt access valves and replaced with permanent soldered fittings. Patched the leaky evaporator with solder and replaced the liquid line drier. Doubled check solder joints for leaks, pulled a vacuum, and then weighed in 9 oz. of R134 refrigerant. Started the unit back up and tested the operation. Refrigerant pressures were approximately 130 psig on the high side and 18 psig on the low. Allowed the unit to run until it cycled off at 34*F. No other issues found and explained services to client.
To learn more about the True T-Series click on the PDF below.
True Mfg Sequence of Ops Manual