Startup And Shutdown - Daikin Pathfinder AWV Installation, Operation And Maintenance Manual

Air-cooled screw chillers

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Table Of Contents

Table of Contents

NOTE: Installation and maintenance are to be performed only

by qualified personnel who are familiar with local codes and

regulations, and experienced with this type of equipment.

LOCKOUT/TAGOUT all forms of hazardous energy and

power sources prior to starting, pressurizing, de-pressuring,

or powering down the chiller. Failure to follow this warning

exactly can result in serious injury or death. Be sure to

read and understand the installation, operation, and service

instructions within this manual.

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.

Dyes used for refrigerant leak detection are not tested

or recommended for use in Daikin chillers. Use of these

products may damage and/or degrade the performance of the

equipment and will void the manufacturer warranty.

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 benefits.

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. Verify requirements from

are met. including flushing the system water piping

before connecting to the unit.

2. Verify chilled water flow rate and calibrate thermal

dispersion flow switch - see instructions on

3. Double check that the discharge shutoff valve and the

optional compressor suction butterfly valves are open.

4. Check that the manual liquid line shutoff valves at the

outlet of the subcooler coils are open.

5. 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.

6. Start the auxiliary equipment for the installation by

turning on the time clock, and/or remote on/off switch,

and chilled water pump.

7. Check to see that pumpdown switches Q1 and Q2 are in

www.DaikinApplied.com

DANGER

CAUTION

"Chilled Water Piping" on page

page

88.

the "Pumpdown and Stop" (open) position. Throw the S1

switch to the "Auto" position.

8. Repeat step 7 for Q2

9. Under the "Control Mode" menu of the keypad, place the

unit into the automatic Cool Mode.

10. Start the system by moving pumpdown switch Q1 to the

"Auto" position.

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.

Do not turn the unit off using the "Override Stop" switch,

without first 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.

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 satisfied, 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.

Water flow to the unit must not be interrupted before the

compressors pump down to avoid freeze-up in the evaporator.

Interruption will cause equipment damage.

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.

IOM 1242-8 • PATHFINDER