Emerson Liebert PEX Series User Manual page 97

92 Chapter 7 System Operation And Maintenance
When the compressor is entirely burned, you need to replace the filter drier together with the compressor. In addition,
check the expansion valve. If the valve is faulty, replace it too. Before the replacement, you must clean the system. If
you are unsure about the cleaning method, please consult Emerson service personnel.
Compressor replacing procedures
1. Cut off the power supply.
2. Connect the LP and HP tubes of the pressure gauge to the schrader valves of the suction and exhaustion pipes
respectively to recycle the refrigerant.
Note
The refrigerant must be recycled or disposed in accordance with the local regulations. Discharging the refrigerant into the air is
harmful to the environment and illegal.
3. Disconnect all the electric connection to the compressor.
4. Disconnect the Rotalocks from the discharge and suction openings on the compressor.
5. Remove the faulty compressor (The compressor of the downflow fan unit has a higher location, so each unit is
configured with compressor replacement frock. For details, see label indication pasted behind the left front door of the
unit).
6. If the compressor has been entirely burned, you need to clean the pipes of the cooling system and replace the filter
drier.
Note
Do not remove the rubber bungs from the suction opening and exhaust opening of the new compressor too early. The time that
the openings are exposed to the air should not exceed 15mins so as to prevent the compressor refrigeration oil from absorbing
water and bringing the water inlet to the system.
7. Install the new compressor, and connect the pipes and electric cables.
8. Evacuate the system and add refrigerant in accordance with the commissioning regulations.
9. Power on the system by following the ordinary startup commissioning procedures and check the system operation
parameters. Observe the refrigerant state through the sight glass, determine the amount of refrigerant to be added by
considering the system pressure and temperature, and stop adding refrigerant until the system enters normal
operation.
Liebert.PEX2 Series Air Conditioner User Manual