IOM 1206-1
61
Start-up and Shut-down Procedures
Table 44: Pumpdown and System Switch Positions
Post Start-up
After the chiller has been operating for a period of time and
has become stable, check the following:
•
Compressor oil level. (Some scroll compressors do not have
oil sight glasses).
•
Refrigerant sight glass for flashing.
•
Rotation of condenser fans.
•
Complete the "Compressorized Equipment Warranty Form."
Shutdown
Temporary Shutdown
1
Put both circuit switches to the OFF position
(Pumpdown and Stop).
2
After compressors have stopped, put System Switch (S1)
to OFF (emergency stop).
3
Turn off chilled water pump. Chilled water pump to
operate while compressors are pumping down.
4
To start the chiller after a temporary shutdown, follow
the start-up instructions.
Extended Shutdown
1
Front seat both condenser liquid line service valves.
2
Put both circuit switches to the OFF position
(Pumpdown and Stop position).
3
After the compressors have stopped, put System Switch
(S1) to the OFF position (emergency stop).
4
Front seat both refrigerant circuit discharge valves (if
applicable).
5
If chilled water system is not drained, maintain power to
the evaporator heater to prevent freezing. Maintain heat
tracing on the chilled water lines.
6
Drain evaporator and water piping to prevent freezing.
7
If electrical power to the unit is on, the compressor
crankcase heaters will keep the liquid refrigerant out of
the compressor oil. This will minimize start-up time
when putting the unit back into service. The evaporator
heater will be able to function.
8
If electrical power is off, make provisions to power the
evaporator heater (if chilled water system is not drained
or is filled with suitable glycol). Tag all opened electrical
disconnect switches to warn against start-up before the
refrigerant valves are in the correct operating position.
To start the chiller after an extended shutdown, follow the
prestart-up and start-up instructions.
Switch
Switch Position
ON
OFF
PS1, PS2,
Pumpdown
Switches
Circuits will
operate in the
normal,
automatic mode
Circuit will go
through the normal
pumpdown cycle
and shut off.
S1, System
Switch
Unit will operate
in the normal
automatic mode
Unit will shut off
immediately without
pumping down
(emergency stop)
