McQuay AGS 206A, Руководство по эксплуатации

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OM AGSB-5 57
Start-up After Temporary Shutdown
1. Insure that the compressor heaters have been energized for at least 12 hours prior to
starting the unit.
2. Start the chilled water pump.
3. With System switch S1 in the "on" position, move pumpdown switches PS1 and PS2 to
the "auto" position.
4. Observe the unit operation until the system has stabilized.
CAUTION
If shutdown occurs, or will continue through periods below freezing ambient
temperatures, protect the chiller vessel from freezing. See Freeze-Up Protection in
this manual for more information.
Extended (Seasonal) Shutdown
1. Move the PS1 and PS2 switches to the manual pumpdown position.
2. After the compressors have pumped down, turn off the chilled water pump.
3. Turn off all power to the unit and to the chilled water pump.
4. If fluid is left in the evaporator, confirm that the evaporator immersion heaters are
operational.
5. Move the emergency stop switch S1 to the "off" position.
6. Close the optional compressor suction valve (if so equipped) as well as the liquid line
shutoff valves.
7. Tag all opened compressor disconnect switches to warn against start-up before opening
the compressor suction valve and liquid line shutoff valves.
8. If glycol is not used in the system, drain all water from the unit evaporator and chilled
water piping if the unit is to be shutdown during winter. Do not leave the vessels or
piping open to the atmosphere over the shutdown period.
9. Do not apply power to the evaporator immersion heaters if the system is drained of
fluids as this can cause the heaters to burn out.
Start-up After Extended (Seasonal) Shutdown
1. With all electrical disconnects locked and tagged open, check all screw or lug-type
electrical connections to be sure they are tight for good electrical contact.
2. Check the voltage of the unit power supply and see that it is within the
±
10% tolerance
that is allowed. Voltage unbalance between phases must be within
±
3%.
3. See that all auxiliary control equipment is operative and that an adequate cooling load is
available for start-up.
4. Check all compressor flange connections for tightness to avoid refrigerant loss. Always
replace valve seal caps.
5. Make sure system switch S1 is in the "Stop" position and pumpdown switches PS1 and
PS2 are set to "Pumpdown and Stop", throw the main power and control disconnect
switches to "on." This will energize the crankcase heaters. Wait a minimum of 12
hours before starting up unit. Turn compressor circuit breakers to "off" position until
ready to start unit.
6. Open the optional compressor suction butterfly as well as the liquid line shutoff valves.