Air-Cooled Condenser; Water-Cooled Condenser; Compressor - Emerson Liebert PEX Series User Manual

7.6.6 Air-Cooled Condenser

Refer to 4.1 Maintenance in Liebert.PEX Condenser User Manual .

7.6.7 Water-Cooled Condenser

BPHE
The turbulence generated in the ducts of soldered BPHE can clean the ducts. However, on occasions when scaling is
serious, like when hot hard water is used, it is necessary to use cyclic rinsing device to clean the BPHE. Put weak acid
(like 5% phosphoric acid) into a jar and use a pump to inject the fluid into the BPHE to clean it. If the BPHE is often
cleaned, use 5% oxalic acid.
The cleaning of the BPHE is not covered by Emerson maintenance service. If necessary, you can consult Emerson
service personnel.
Electronic ball valve
The iCOM controller controls the electronic ball valve position by collecting the refrigerant pressure of the BPHE outlet
from the pressure sensor, so as to control the water flow through the BPHE for system stable operation. The higher the
load is, the more water flow is allowed to flow through the BPHE. The lower the load is, the less water flow is allowed
to flow through the BPHE.
Test function
If the electronic ball valve is in abnormal regulation state, please consult Emerson service personnel.

7.6.8 Compressor

Warning
No direct contact between the refrigerant or lubricant and the skin when replacing the compressor, or serious burning or frostbite
may occur. Put on gloves with long sleeves when processing polluted parts.
The Liebert.PEX air conditioner system uses the Copeland scroll compressor with high efficiency and high reliability. It
is rare for the motor of the compressor to get burned due to short circuit. In the few cases that the motor does get
burned, the cause is usually mechanical problem or poor lubrication, in other words, due to over-temperature.
If the causes that lead to the compressor failure could be discovered and corrected in time, most failures are avoidable.
The maintenance personnel should check the operation situation periodically and take necessary measures to ensure
the system normal operation. This practice is both easy and cost saving, when you compare it with replacing the
compressor upon faults that result from negligence or inadequate maintenance.
When diagnosing the compressor, check the operation situation of all the electric parts of the compressor.
1. Check all the fuses and circuit breakers.
2. Check the operation of high pressure and low pressure switches.
3. When the compressor is faulty, find out the nature of the cause: is it an electrical fault or a mechanical fault?
Mechanical faults
It is impossible to diagnose a mechanical fault of the compressor by smelling the burning. You should try spinning the
motor. If the fault is proved to be mechanical, the compressor has to be replaced. If the motor is burned, you 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.
Electric faults
You can tell an electric fault by the unpleasant smell. If serious burning occurred, the lubricant will appear black and
become acidic. When electric 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.
Note
The damage to the compressor components due to improper cleaning is classified in the warranty agreement as improper use of
the product, thus is not covered by the warranty.
Liebert.PEX2 Series Air Conditioner User Manual
Chapter 7 System Operation And Maintenance 91