Daikin McQuay AGZ-D Operating And Maintenance Manual page 67

Extended
1. Front seat (close) both condenser liquid line service valves.
2. Put both circuit switches (PS1 and PS2) to the OFF position (Pumpdown and Stop position).
3. After the compressors have stopped, put System Switch (SW1) 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 filled with correct anti-freeze). 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.
Pre Startup Water Piping Checkout
1. Check the pump operation and vent all air from the system.
2. Circulate evaporator water, checking for proper system pressure and evaporator pressure drop.
Compare the pressure drop to the evaporator water pressure drop curve.
3. Clean all water strainers before placing the chiller into service.
Pre Startup Refrigerant Piping Checkout
1. Check all exposed brazed joints for evidence of leaks. Joints may have been damaged during
shipping or when the unit was installed.
2. Check that all refrigerant valves are either opened or closed as required for proper operation of the
chiller.
3. A thorough leak test must be done using an approved electronic leak detector. Check all valve
stem packing for leaks. Replace all refrigerant valve caps and tighten.
4. Check all refrigerant lines to insure that they will not vibrate against each other or against other
chiller components and are properly supported.
5. Look for any signs of refrigerant leaks around the condenser coils and for damage during shipping
or installation.
6. Leak detector fluid may be applied externally to refrigerant joints at the factory. Do not confuse
this residue with an oil leak.
7. Connect refrigerant service gauges to each refrigerant circuit before starting unit.
Pre Startup Electrical Check Out
Electrical power must be applied to the compressor crankcase heaters 8 hours before
starting unit to drive off refrigerant from the oil and prevent damage to the unit.
1. Open all electrical disconnects and check all power wiring connections. Start at the power block
and check all connections through all components to and including the compressor terminals.
These should be checked again after 3 months of operation and at least yearly thereafter.
2. Check all control wiring by pulling on the wire at the spade connections and tighten all screw
connections. Check plug-in relays for proper seating and to insure retaining clips are installed.
3. Put System Switch (S1) to the Emergency Stop position.
OMM 1087
CAUTION
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AGZ 025D through 190D 67