Refrigerator operating principles and symptoms
Refrigerator Troubleshooting – Symptoms of system faults
When a plant has been charged it must be established that the charge is in fact complete. The disappearance of bubbles in a sight glass does not necessarily mean that the evaporator is correctly flooded. Continued adding of refrigerant when bubbles show in the sight glass can also result in the system being overcharged.
Shortage of [...]
Refrigerator Troubleshooting – Compressor pressure ratio
This is the ratio between the suction pressure and the discharge pressure. No refrigeration compressor is 100 per cent efficient, owing to various losses. It is considered that a compressor is 80 to 85 per cent efficient with pressure
ratios of 4:1 to 6:1.
With a suction pressure of 2 bar, the operating head pressure could be [...]
Refrigerator Troubleshooting – Calculating the operating head pressure
Manufacturers of refrigeration condensing units will supply technical data for their products on demand, but this will be based on ideal operating conditions in controlled ambient temperatures. The service engineer or technician, dealing with many different types of equipment, needs a simple quick method to enable him to determine the theoretical operating head pressure of [...]
8Nov2009 | admin | 0 comments | ContinuedRefrigerator Troubleshooting – Temperature, humidity and air motion in food storage
It is important that the temperature difference (TD) between the product being stored and the refrigerant is correct for that product. Too wide a TD will result in excessive dehydration of the product. Too close a TD can result in rapid deterioration of the product; fresh meat, for example, will soon become discoloured and slimy [...]
8Nov2009 | admin | 0 comments | Continued