A．too much superheat
B．insufficient superheat
C．suction pressure too low
D．excessive refrigerant returning to the compressor
[单选题]In the refrigeration system, a shortage of refrigerant is indicated byA．the compressor short cycling on high pressure cut out switchB．high suction pressureC．high head pressureD．bubbles in the sight glass
[单选题]If a refrigeration system were short of refrigerant, the condition would result inA．continuous running of the compressorB．high suction pressureC．high discharge pressureD．short cycling of the compressor on the water failure switch
[问答题]()He is sweating all over.
[单选题]If the refrigeration compressor crankcase is sweating, the cause may be due toA．a shortage of refrigerantB．the compressor running continuouslyC．liquid refrigerant returning to the compressorD．the compressor short cycling on the high pressure cutout
[单选题]When the refrigeration demand is small,_______.A．the expansion valve will move toward the wide open positionB．the expansion valve will move toward the closing positionC．the feeler bulb will conveys the high temperatureD．the superheat degree will rais
[单选题]If a refrigeration compressor is short cycling on high head pressure, you shouldA．purge the condenser if the waterside is dirtyB．check for proper water flow through the condenserC．increase the high pressure cutout settingD．reduce the cooling water fl
[单选题]Moisture is removed from a refrigeration system byA．bleeding refrigerant from the condenserB．opening a drain petcock on the oil separatorC．condensing the water in the heat exchangerD．using a dehydrator cartridge
[单选题]If a refrigeration compressor is short cycling on high head pressure, you should _______.A．purge the condenser if the waterside is dirtyB．check for proper water flow through the condenserC．increase the high pressure cutout settingD．reduce the cooling
[填空题] （）是全球移动通信系统（Global system for mobile communication）的简称。
[单选题]When adding oil to a refrigeration system, precautions must be taken to ensure thatA．the compressor suction pressure is not too highB．all air is purged from the pump and charging fittingsC．the high pressure cutout switch is held open to prevent accid