Air Cooled Condenser; Filter - Emerson Liebert.PEX+ Series User Manual

5. Check the connection between the user terminals (70#, 71#, 70A#, 71A#, 37#, 38#) and the control interface board.
6. Check the output connection between the control interface board and various contactors and solenoid valves for
liquid pipes, and the input connection between control interface board and fan overload protector, high pressure
switch, heating over-temperature protection switch, humidifier protection switches, discharge air temperature sensor,
and low pressure sensor. In particular, check the connection parts such as high pressure switches and solenoid
valves, and replace the component if in poor connection or faulty.
7. Check and replace electrical components that are faulty, such as control fuses (or MCBs) and control boards.
8. Check the specification and aging condition of the control cable and power cable between the indoor unit and the
condenser, and replace the cables when necessary.
9. Use temperature and humidity measuring meters with higher precision to measure and calibrate the temperature
and humidity sensors.
 Note
 Set the humidity control mode to 'relative humidity control' during calibration process.
10. Adjust the setpoints. Check the action of the functional parts and the auto-flush control logic of water pan of the
infrared humidifier according to control logic.
11. Simulate and check the operation of the protection devices including high and low pressure alarm, high and low
temperature alarm, high water level alarm and over-temperature protection.
12. Check the water detection sensor.
Bridge the water detection sensor probes and confirm the alarm through the controller.
The sensor should be placed away from any water pool or drainage trench on the floor, 2m ~ 2.5m away from the unit.
Do not place it directly under the unit. The recommended installation location of the water detection sensor is shown in
Figure 7-1.
！
warning

Before fastening the connection of any mechanical parts or cables, make sure that the power supply of the
control unit has been disconnected.
 Do not use the water detection sensor adjacent to flammable liquid or use it to detect flammable liquid.

7.6 Air Cooled Condenser

Refer to associated condenser user manual for details.

7.7 Filter

The efficiency of the filter in the unit is 30%, which complies with US ASHRAE52-76 and Eurovent 4/5 standards, and
the dust resistance value is 90%(EU4 standard).To ensure the normal operation of the filter, the filter service alarm
logic is provided by the controller. The default fan running time is 2000 hours, when the time is exceeded, the filter
Location of water
detection sensor
Location of water
detection sensor
Figure 7-1 Recommended location for the water detection sensor
Liebert. PEX+Series Precision Air Conditioner
Chapter 7 System Operation And Maintenance
Liebert unit
Drain pipes on the ground
User Manual
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