AIR CONDITIONING
5
STEP 3 - CONNECT PRESSURE GAUGE
Sr.No.
PROBLEM / SYMPTOMS
POSSIBLE CAUSED
REMEDY
1
LOW SIDE-HIGH (>3.5
kg/cm2) HIGH SIDE - HIGH
(>28 kg/cm2 & Discharge air is
warm
1. Large amount of air present
in system. This can be
because of insufficient
evacuation. 2. Dirt in
Expansion valve (TXV) 3.
Moisture in refrigerant circuit.
1. Discharge the system.
2. Change the filter drier
cartridge
3. Evacuate the system
4. Charge refrigerant gas & oil
qty.
5. Check performance by
ODT/ CDT.
2
LOW SIDE-LOW (<3.5 kg/
cm2) HIGH SIDE - LOW (<28
kg/ cm2 & Discharge air is
warm
1. Expansion valve is stuck
open 2. Evaporator is getting
flooding
Change Expansion valve
3
LOW SIDE-HIGH (>3.5 kg/
cm2) HIGH SIDE - HIGH (>28
kg/ cm2 & Discharge air is
warm High pressure side
tubes are very hot
OR
Compressor clutch could
continually cycle on high
1. Excessive refrigerant
quantity,
1. Discharge the system.
2. Change the filter drier
cartridge
3. Evacuate the system
4. Charge refrigerant gas & oil
qty.
5. Check performance by
ODT/ CDT.
pressure switch. Pressure
does not come down to normal
when cooled by water.
2. Poor condenser cooling.
Engine fan not working
Engine fan direction reverse
Check pressure switch
connections & Radiator Fan
direction. Also check
clearance between Radiator &
condenser.
3. Condenser FINS are
clogged
Clean Condenser
4. Radiator Overheating
Check Coolant & other
radiator problems
5. Check Linear pressure
switch & it’s electric terminals
If terminals are damaged
1. Discharge the system.
2. Change the Pressure switch
3. Evacuate the system
4. Charge refrigerant gas & oil
qty.
5. Check performance by
ODT/ CDT.
4
LOW SIDE - low (< 1.8 kg/
cm2) or Vacuum. HIGH SIDE -
HIGH (>28 kg/ cm2 &
discharge air slightly cool.
Expansion valve stuck closed
Foreign material or moisture
entry
1. Discharge the system.
2. Change the expansion
valve (TXV)
3. Evacuate the system
4. Charge refrigerant gas & oil
qty.
5. Check performance by
ODT/ CDT.
