DIRECT EXPANSION AIR CONDITIONING - Quiz

1) What is the reason for short cycling of LP control switch in AC plant?

Excess of water flow Excess of refrigerant Shortage of water flow Shortage of refrigerant

2) Which parameters in log sheet indicate the air blocking in ducts?

All grille temperatures Liquid line temperature Inlet and outlet temperature of chillier Temperatures in chilled water system

3) What is the effect on system performance if the AC system is at undercharged condition?

Poor cooling Excess cooling Compressor over loading Compressor trips by HP cut out

4) What is the cause of oil foaming in compressor crankcase at the time of starting?

Poor condensation Damaged oil separator Excess oil in crankcase Defective oil heater/circuit

5) Why the LP cut out control is bypassed electrically before pump down operation?

Avoid oil foaming Prevent liquid entry to compressor Increase current of the compressor motor To lower the suction pressure close to 0.5 kg/cm²