(1)At normal operation conditions, the temperature around the surface of freezer evaporator is nearly the same; the thickness of frost layer is similar. If there is no frost at the surface of evaporator (bed type freezer at all of its inner wall), or only a small part at the upper, conclusion can be made that the operation of refrigeration system is not normal, the refrigerant is insufficient or there is leakage.
(2)Check the system tubing and make sure there is no leakage, especially at the joint connections. Refrigerant has good permeability, and it also contains a little refrigerant oil. If there is leak, there will be traces of oil at the leak points.
12.1.4 Troubleshooting by sounds
(1)When the freezer is working normal,
be heard. Open the freezer door and access to the evaporator, you can hear the sound. If there is no sound or there is sound a little now and then, there must be leakage of system refrigerant or insufficient charge.
MAINTENANCE SERVICE AND TROUBLE SHOOTING
Maintenance Service and Trouble Shooting
(2)After switching on power, Listen to the running sound of the compressor whether it is normal or not. Whether or not hear
１８
PDF created with pdfFactory trial version www.pdffactory.com