INSTALLATION (CONTINUED)
14
TEST RUN
Check that all tubing and wiring have been completed correctly. Check again that the wide and narrow tube service
valves are fully opened. Turn on the power and run the system.
Service Valve Construction
• Valve Position Closed
The valve systems of both the wide and narrow tubes are turned all the way in. The unit is shipped from the factory in
this position and it is also used for Pump Down and Air Purging.
• Valve Position Fully Open
The valve stems of both the wide and narrow tubes are turned all the way out. This is normal operating and Test Run
position.
• Valve Position Half Open
With the narrow tube valve stem is turned to the halfway-down position. This position is used for pressure measure-
ment and gas charging.
CAUTION:
When opening or closing the service valve stem, be sure to use a hex wrench.
PUMP DOWN
Pump Down means collecting all refrigerant in the outdoor unit without loss in refrigerant gas.
This is performed when the unit is to be relocated or the refrigerant circuit is serviced.
CAUTION:
Be sure to perform Pump Down procedure with the unit cooling mode.
Pump Down Procedure
1. Connect a low-pressure gauge manifold hose to the charge port on the wide tube service valve.
2. Open the wide tube service valve halfway and purge the air from the manifold hose using the refrigerant gas.
3. Close the narrow tube service valve (all the way in).
4. Turn on the unit’s operating switch and start the cooling operation.
5. When the low-pressure gauge reading becomes 1 to 0.5 kg/cm2 (14.2 to 7.1 psi), fully close the wide tube valve stem
and then quickly turn off the unit. At that time, Pump Down has been completed and all refrigerant gas will have been
collected in the outdoor unit.
