Daikin AWV024 - Startup, Shutdown, and Maintenance; Startup and Shutdown Procedures

sTarTup and shuTdown
www.DaikinApplied.com 83 IOM 1242-2 • PATHFINDER
®
MODEL AWV CHILLERS
sTarTup and shuTdown
Pre-startup
Inspect the chiller to ensure no components became loose or
damaged during shipping or installation, including leak test and
wiring check. Complete the pre-start checklist at the front of
this manual and return to Daikin Applied prior to startup date.
NOTICE
Daikin Applied service personnel or factory authorized
service agency must perform initial startup in order to activate
warranty. Return the “Screw Compressor Equipment Warranty
Form” within 10 working days to Daikin Applied as instructed
on the form to obtain full warranty benets.
CAUTION
Most relays and terminals in the unit control center are
powered when S1 is closed and the control circuit disconnect
is on. Therefore, do not close S1 until ready for startup or the
unit may start unintentionally and possibly cause equipment
damage.
Startup
1. Double check that the discharge shutoff valve and the
optional compressor suction buttery valves are open.
2. Check that the manual liquid line shutoff valves at the
outlet of the subcooler coils are open.
3. Check the leaving chilled water temperature set point
on the MicroTech
®
III controller to be sure it is set at the
desired chilled water temperature.
4. Start the auxiliary equipment for the installation by
turning on the time clock, and/or remote on/off switch,
and chilled water pump.
5. Check to see that pumpdown switches Q1 and Q2 are in
the “Pumpdown and Stop” (open) position. Throw the S1
switch to the “Auto” position.
6. Under the “Control Mode” menu of the keypad, place the
unit into the automatic Cool Mode.
7. Start the system by moving pumpdown switch Q1 to the
“Auto” position.
8. Repeat step 7 for Q2.
Temporary Shutdown
Move pumpdown switches Q1 and Q2 to the “Pumpdown and
Stop” position. After the compressors have pumped down, turn
off the chilled water pump.
CAUTION
Do not turn the unit off using the “Override Stop” switch,
without rst moving Q1 and Q2 to the “Stop” position, unless
it is an emergency, as this will prevent the unit from going
through a proper shutdown/pumpdown sequence, resulting in
possible equipment damage.
CAUTION
The unit has a onetime pumpdown operation. When Q1
and Q2 are in the “Pumpdown and Stop” position, the unit
will pump down once and not run again until the Q1 and Q2
switches are moved to the “Auto” position. If Q1 and Q2 are
in the “Auto” position and the load has been satised, the unit
will go into onetime pumpdown and will remain off until the
MicroTech
®
III control senses a call for cooling and starts the
unit.
CAUTION
Water ow to the unit must not be interrupted before the
compressors pump down to avoid freeze-up in the evaporator.
Interruption will cause equipment damage.
CAUTION
If all power to the unit is turned off, the compressor heaters
will become inoperable. Once power is resumed to the unit,
the compressor and oil separator heaters must be energized
a minimum of 12 hours before attempting to start the unit.
Failure to do so can damage the compressors due to
excessive accumulation of liquid in the compressor.
Startup After Temporary Shutdown
1. Insure that the compressor and oil separator heaters
have been energized for at least 12 hours prior to
starting the unit.
2. Start the chilled water pump.
3. With system switch Q0 in the “On” position, move
pumpdown switches Q1 and Q2 to the “Auto” position.
4. Observe the unit operation until the system has
stabilized.
Extended (Seasonal) Shutdown
1. Move the Q1 and Q2 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 uid is left in the evaporator, conrm that the
evaporator heaters are operational.
5. Move the emergency stop switch S1 to the “Off” position.
6. Close the compressor discharge valve and 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 startup before opening the compressor suction
valve and liquid line shutoff valves.