Vertiv Liebert CR045 - Page 109

Vertiv | Liebert® CRV4 | User Manual 98
System Operation and Maintenance
• Mechanical faults
It is impossible to diagnose a mechanical fault of the compressor by smelling the burning. User should try
spinning the motor. If the fault is proved to be mechanical, the compressor has to be replaced. If the motor is
burned, user should remove the fault that leads to the burning of the motor and clean the system. It must be
pointed out that the compressor motor is usually burned because the system is not cleaned properly.
• Electrical faults
User can tell an electrical fault by the unpleasant smell. If serious burning occurred, the lubricant will appear
black and become acidic. When electrical fault occurs and the compressor motor is entirely burned, the system
must be cleaned to remove the acid material from the system and to avoid such faults in the future.
• The compressor replacement needs to be guided or implemented by a professional. If you need to
replace it, contact Vertiv representative.
• The damage to the compressor components due to improper cleaning is classied in the warranty
agreement as improper use of the product, thus is not covered by the warranty.
When the compressor is entirely burned, user needs to replace the lter dryer together with the compressor. In
addition, check the expansion valve. If the valve is faulty, replace it too. Before the replacement, user must clean
the system. If unsure about the cleaning method, please consult Vertiv representative for the support.
Following are the procedures to replace the compressor:
1. Cut o the whole power supply.
2. Standard steps are adopted to recover residual refrigerants in the system.
3. Remove the damaged compressor, remove the lter dryer, and clean the system according to the
instructions of the cleaning tools.
4. Install the replaceed compressor and lter dryer, the tightening torque of exhaust pipe thread joint is
130 N.m, the tightening torque of suction pipe thread joint is 150 N.m, and the torque required for connecting
moment of lter dryer threading is 45 N.m.
5. The pressure leak detection test of the system shows that the leak detection pressure is about 10 bar. If
there is no problem, the system is vacuum.
6. Refrigerant charging is carried out according to the charging requirement of evaporator, condenser and
refrigeration pipeline. For the refrigerant charging process refer “Section 5.2.2 Charging refrigerant”.
7. Turn On the power supply and run the air conditioning unit. Check whether the refrigeration operation is
normal. Refer to the normal refrigeration cycle suction and exhaust pressure range, when necessary, dynamic
supplement of a certain amount of refrigerant can be performed.