Trane CXAJ series Installation, Operation And Maintenance Manual page 30

Unit Operation
• In winter, it is necessary to close the water supply valves of all evaporators, open the drain
Start this System after Long-term Shutdown
1. Open the valves of the water return and supply pipes, and fill with clear water into the chilled
2. Short-circuit the wire of the flow switch to measure the water system.
3. Turn on the power switch of the unit.
4. Press ON/OFF button on the control panel to start the unit. When the chilled water is
5. Adjust the water flow of the chilled water pipe through the balance valve, and inspect the
6. Adjust the flow switch (installed on the water outlet pipe of the unit) to ensure the normal
7. Press ON/OFF button on the control panel to start or stop the unit.
8. Reconnect the wire of the flow switch.
At this time, the unit can normally operate.
When the water pump operates, adjust the water flow to the half of the maximum flow, and
disconnect the contact of the flow switch. Please use the ohmmeter to verify on and off of the
switch contact.
System Protection
Low-pressure protection (LP1, LP2) (N Type Unit Only)
The unit is under the protection of the low pressure switch. When the operating pressure is lower
than 21 ± 7 psig (0.1145 ± 0.048 MPa), the operation of compressor will be stopped; when the
operating pressure is up to 36 ± 7 psig (0.248 ± 0.048 MPa), the compressor will be automatically
reset. There will be 2-minute short circuit when starting to avoid unnecessary shutdown.
High-pressure protection (HP1, HP2)
The unit is under the protection of the high pressure switch. When the high pressure is higher
than 602 ± 22 psig (4.15 ± 0.15 MPa), the operation of compressor will be stopped; when the
pressure is reduced to 479 ± 22 psig (3.303 ± 0.152 MPa), the compressor will be automatically
reset.
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drainage opening at the bottom of the water pump and the shell and tube heat exchanger
to ensure that the circulating water is drained off.
4. Turn off the power switches of the unit and water pump.
Cautions
valve and the exhaust valve on the unit pipeline to drain the water in the evaporator, and then
install the drain plug. For the ultra-thin ceiling unit, first drain off the water in the pipeline,
and then open the drain valve at the bottom to drain off the residual water in the evaporator.
If the water in the chilled water pipe cannot be fully drained off, the proper antifreeze liquid
can be injected to prevent the residual water from being frozen and thus damaging the unit.
water pipe. Be sure to exhaust when filling with water. After the system is filled with water,
close the exhaust valve.
circulated in the water system, inspect whether all pipe connectors leaks or not.
water pressure of the unit.
operation.
Caution