AC Technician interview. Ductable Ac. Package AC. Split AC. Windows and DX VRV unit and FCU . Ahu

#Function of safety controls. ANS: L.P Switch will trip when lower than set point/HP trip when higher than set point/ same as oil and flow switch.
#Type and function of Expansion valve. #HoW to check compressor winding.
#Temperature control: Required temperature for the human body is 72-degree F to 78-degree F.
#What are various components of refrigeration system?
#What is the normal discharge pressure of Freon 12? 100-150 PSI
#What is the normal discharge pressure of Freon 22? 10. 200-350 PSI
Give the definition of super heat. Heat absorbed by the vapor above its boiling point at its existing pressure is called super heat
#How to convert from Celsius to Fahrenheit, give one example? X 21. F =C*9/5+32, eg;100*9/5=20*9=180,180+32=212degree F
#What are reasons if the temperature in the conditioned is too low? Defective room thermostat, defective capacity control, over tonnage of the machine.
#Why the discharge pressure is too low? Low ambient temperature, leaking discharge valve (loose compression), compressor is working on unload condition, internal HP relief valve defective.
#Why the suction pressure is too low? 37/suction strainer chocked up, filter choke up, blower fan not working properly, defective expansion valve, under charge, cooling coil choke up.
#Why the oil pressure is very low? Oil strainer dirty or choke up, less oil in the crank case, liquid refrigerant in the crank case, oil pump May faulty.
#How much vacuum can be creating with the rotary vacuum pump? 41. Rotary vacuum pump can create -30 Hg (mercury) only.
#One ton of refrigeration is equal to how many Kcal/day 51. 72,000 Kcal/day, 2, 88,000 Btu/day or 3000 Kcal/hr or 12000 8tu/hr.
#What is the function of the thermostat? To keep up the desire temperature.
#Capacity calculation for three phase compressors? LRA divided by 12
#Capacity calculation for the single-phase compressor? LRA divided by 36
#How much is the differential setting of a room thermostat? 74. 1.5 degree For 1 degree C
#How can be testing the ELCB? By pushing the test button or touch with neutral line or make any leakage.