63 | P a g e
Notes: Do not use the R22 and air mixture or oxygen to raise the pressure to
prevent explosion.
If there is a leak at brazing point, or a washer replacement is needed, it is
necessary to reclaim all refrigerant before proceeding with the hot work or
replacement work.
After work done, the vacuum process is required by the following procedures.
7.3.5 Vacuum
Vacuum is indispensable before charging in new refrigerant. If no leak detected
after leak test, vacuum the chiller with vacuum pump. The vacuum level must
reach 100Pa and holding pressure should not raise more than 10Pa per hour.
Long Idle Period Maintenance
• If the unit is to be left idle for a long time, completely drain water in the pipes
and the unit. Otherwise water leakage and damages to the heat exchanger may
occur due to freezing. Especially in winter, water in idle units must be completely
drained. You can also fill up the water system with antifreeze liquid after shutting
down the unit. Contact McQuay for detailed information about the density of the
antifreeze liquid.
• The power supply must be cut off; otherwise the electric heater in the crankcase
is still powered up and may waste energy.
• Before starting the unit that is left idle for a long time, power up the unit 24
hours beforehand. This ensures that the electric heater in the crankcase is powered
up and that the compressor is heated and conditioned for smooth operation.
To Next Page
Loading...
