G&D GD-20H User manual

1.800.555.0973
[e-mail]
GDCHILLERS.COM/INSTALLATION-VIDEOS
CHILLER INSTALLATION
GUIDE & USER MANUAL
-GD-20H & GD-27H CHILLERS -

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2
GD-20H & GD-27H CHILLER MANUAL
©2021 G&D CHILLERS, INC.
ALL RIGHTS RESERVED

INSTALLATION GUIDE •USER MANUAL GD-20H & GD-27H MODELS
3
G&D CHILLERS, INC. •GD-20-27H-MS_CRL-r2021A
CONTENTS
CONTACT INFORMATION & AFTERHOURS SUPPORT ......................................................... 4
INSTALLATION VIDEO LINKS................................................................................................ 4
PACKAGE CHILLER DESCRIPTION ........................................................................................ 5
INSTALLATION REQUIREMENTS.......................................................................................... 6
PIPING RECOMMENDATIONS ............................................................................................. 7
CONTROLLER AND NAVIGATION ........................................................................................ 9
C.PCO CAREL MINI ALARMS ............................................................................................. 10
START-UP INSTRUCTIONS ................................................................................................. 12
WARRANTY START-UP CHECKLIST..................................................................................... 13
SEQUENCE OF OPERATION ............................................................................................... 14
MAINTENANCE..................................................................................................................14
TROUBLESHOOTING...........................................................................................................15
PROPYLENE GLYCOL CHART............................................................................................... 18
WARRANTY STATEMENT................................................................................................... 19

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4
CONTACT INFORMATION & AFTERHOURS SUPPORT
CONTACT INFORMATION
G&D Chillers, Inc.
760 Bailey Hill Rd.
Eugene, Oregon 97402
1.800.555.0973
[email protected]
Office Hours: 8 AM – 5 PM PST
AFTERHOURS TECHNICAL SUPPORT
G&D Chillers offers 24/7 technical support. For emergency assistance after normal business hours, call the main office
at 1.800.555.0973. The voicemail recording will provide contact information for the emergency on-call service
technician.
INSTALLATION VIDEO LINKS
Visit the following pages for installation video walk-throughs and FAQs:
gdchillers.com/installation-videos/
gdchillers.com/installation-videos/how-to-install-a-chiller
gdchillers.com/faq
NOTICE: CHILLER WARRANTY REQUIRES ACTIVATION
To activate the chiller parts and labor limited warranty, complete the
Warranty Start-Up Checklist and return to G&D Chillers within 30 days.

INSTALLATION GUIDE •USER MANUAL
5
PACKAGE CHILLER DESCRIPTION
CONDENSER
AIR COOLED – Standard configuration. Copper tube
aluminum fin condenser coil or micro-channel
condenser coil. Direct drive propeller type fans with
DDP motors and built-in overload protection. Design
test pressure 150 PSIG low side, 300 high side.
LIQUID COOLED – Optional configuration. Brazed
plate counterflow condenser with water regulation
valve. Shell and tube condensers available for custom
units.
EVAPORATOR
Brazed plate counterflow heat exchanger fed by
electronic expansion valve.
COMPRESSOR
Hermetically-sealed Maneurop compressor with oil
level sight glass, rotalock service valves, and
crankcase heater.
CIRCULATION PUMP
End suction centrifugal pump with impeller trimmed
for 35% propylene glycol mixture. Base mounted.
Pump fitted with union, check valve, and supply and
return shut off valves for service. Variable frequency
drives available upon request.
RESERVOIR TANK
Constructed of molded, seamless high-density cross-
linked polyethylene or stainless steel. Insulated with
½” closed cell foam. Glycol level indicator. Auxiliary
ports standard on most units.
SUPPLY & RETURN PIPING
Constructed of type M copper. Ball valves or flanges
provided for field connection of supply and return
piping. Liquid-filled pressure gauge for setting
discharge pressure.
DYNAMIC FLUID BYPASS VALVE
Allows for balancing of discharge pressure. Over
pressure design allows circuiting back to tank without
damage to system or pump. Copper and bronze
construction.
REFRIGERANT PIPING
Type L ACR copper. Liquid line-filter drier, sight
glass/moisture indicator, solenoid valve and
electronic expansion valve with equalizer. Suction line
fully insulated and designed for proper oil return with
minimum friction loss. Discharge line formed of ACR
tubing reformed radius fittings. All piping leak tested
and evacuated. Ships with full operating charge of
refrigerant, refer to data plate for refrigerant type
and charge per circuit.
FRAME & HOUSING
Fully powder coated steel frame. Durable powder
coated aluminum housing rated for outdoor use.
Louvered access panels for easy service and
maintenance.
POWER & CONTROLS
A single-point electrical connection is provided for
terminating the chiller power wiring. All power
starting controls and safety/operating controls are
mounted in a weatherproof steel NEMA 3R enclosure.
Features include:
•Programmable logic controller (PLC)
•On / pump down / off door switch
•Compressor contactor and circuit breaker
•Pump contactor and circuit breaker
•Pressure-based mechanical safeties
•Flow switch interlock
•Freeze protection interlock
•High temperature alarm
•Low ambient control
•Compressor anti short cycle timer
•Fan cycling switches (air cooled units)
•Water regulating valve (water cooled units)
FACTORY TESTING
All chillers are run tested at the factory and verified
to be in perfect working order prior to shipment.
G&D CHILLERS, INC. •GD-20-27H-MS_CRL-r2021A
GD-20H & GD-27H MODELS

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6
INSTALLATION REQUIREMENTS
LOCATION
Air cooled units must sit outside on a
solid level surface. A concrete pad is
recommended. Location should be free
of grass and other debris that could plug
condenser fins.
Ensure minimum clearance* between
condenser intake side and any buildings,
walls, etc.
No walls or obstructions in front of the
unit: Louvered access side must be open
to free air.
Liquid cooled chillers may be installed on
a concrete pad indoors or outdoors. A
properly sized pump and liquid cooling
system for the chiller condenser must be
supplied by the end user. Contact G&D
Chillers for additional information and
assistance with sizing.
ELECTRICAL
1. Supply unit with the proper voltage and protect against power spikes.
Use only copper wire. Size wire and according to any/all applicable
local and national codes. Refer to chart to the right for proper torque
values. Refer to spec sticker on control panel for all electrical ratings.
2. Field-installed service disconnect required
3. Unit must be properly grounded at the provided grounding lug.
If multiple ground wires are used, all wires must be twisted together
prior to tightening ground lug.
4. Use only hubs or fittings that maintain thesame environmental ratings
as the enclosure.
5. When turning unit off for an extended length of time, leave power
energized. (This will leave the crankcase heater on and keep the
crankcase warm for the next start up.)
TORQUE CHART
Gauge
lbf-in
1000-500
550
500-4
500
350-6
375
250-6
375
4/0-6
275
2/0-14
120
#2-#3
50
#4-#6
45
#8
40
#10-#14
35
DO
NOT
BLOCK
WARNING: OBEY ALL APPLICABLE LOCAL AND NATIONAL ELECTRIC CODES WHEN INSTALLING THIS EQUIPMENT
*AIR INTAKE SIDE MINIMUM
CLEARANCE REQUIREMENTS
30" GD-20H, GD-27H

INSTALLATION GUIDE USER MANUAL
7
PIPING RECOMMENDATIONS
Insulate supply and return piping
dŚĞdrawing on the next page shows ĨĞĂƚƵƌĞƐƚŚĂƚƐŚŽƵůĚďĞŝŶĐůƵĚĞĚŝŶƚŚĞƉŝƉŝŶŐƐLJƐƚĞŵ Supplemental details
and additional recommendations are listed here:
xdrue union or flangedǀĂůǀĞƐĨŽƌƐĞƌǀŝĐĞĂďŝůŝƚLJ
z-ƐƚƌĂŝŶĞƌ;ϮϬŵĞƐŚͿon chiller return line
xStandard ball valve on purge line
xAdditional ball valve upstream ofY-strainer for servicing
xŚĞĐŬǀĂůǀĞŽŶĐŚŝůůĞƌƐƵƉƉůLJůŝŶĞ
xdǁŽŽƉƚŝŽŶƐĨŽƌƌĞƚƵƌŶůŝŶĞ
;ϭͿ /ŶǀĞƌƚĞĚƚƌĂƉǁŝƚŚĂŝƌǀĞŶƚǀĂůǀĞĂŶĚǀĂĐƵƵŵďƌĞĂŬĞƌŽƌ
;ϮͿ ůĞĐƚƌŽŶŝĐĂĐƚƵĂƚĞĚǀĂůǀĞǁŝƌĞĚƚŽƉƌŽĐĞƐƐƉƵŵƉƐƚĂƌƚĞƌ
ŝŶĐŚŝůůĞƌĞůĞĐƚƌŝĐĂůĞŶĐůŽƐƵƌĞ
xUse closed-cell foam insulation
xInstall protective cladding
DĂƚĞƌŝĂůƐ^ĐŚĞĚƵůĞϴϬWsŽƌ^typical for cold glycol/water systems
xVerify operating temperatures
xHigh temp systems may require copperor stainless steel piping
/ŶƐƚĂůůŝƐŽůĂƚŝŽŶďĂůůǀĂůǀĞƐĞdžƚĞƌŶĂůůLJĂƚĐŚŝůůĞƌƐƵƉƉůLJĂŶĚƌĞƚƵƌŶƉŽƌƚƐ
'ůLJĐŽůďĂĐŬĨůŽǁƉƌĞǀĞŶƚŝŽŶŵĞĂƐƵƌĞƐ
xůŽƐĞďĂůůǀĂůǀĞŽŶƐƵƉƉůLJůŝŶĞ;ĞdžƚĞƌŶĂůƚŽĐŚŝůůĞƌͿ
xLoosen packingŶƵƚŽŶďLJƉĂƐƐǀĂůǀĞ
xdƵrn handwheelƚŽĐŚĂŶŐĞƉƌĞƐƐƵƌĞ
xDŽŶŝƚŽƌƵƐŝŶŐƉƌĞƐƐƵƌĞŐĂƵŐĞŝŶĐŚŝůůĞƌ
xRetighten packing nut oncepressure is set
EKd/Do not open supply ball valve until gauge showspressure within
tank jacket rating. If your process pump is equipped with a VFD,
set the control pressure set point to 100 psi then adjust the
bypass valve to a pressure that is lower than the maximum
rated pressure of your process loop. After adjustment is
complete, reset the control pressure setpoint to your desired
operating pressure.
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ƐƵƉƉůLJƉƌĞƐƐƵƌĞŝƐĨĂĐƚŽƌLJƐĞƚĂƚϮϬW^/
dŽĂĚũƵƐƚƚŚĞƉƌĞƐƐƵƌĞƐĞƚƚŝŶŐƵƐŝŶŐƚŚĞďLJƉĂƐƐǀĂůǀĞ
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GD-20H & GD-27H MODELS
G&D CHILLERS, INC. •GD-20-27H-MS_CRL-r2021A
Size strainer one pipe size larger than mainline piping size
x

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I
CONTROLLER AND NAVIGATION
:ENTER
:DOWN
:ALARM
:PROGRAM
:ESCAPE
:SET
:INFO
:POWER
Set Screens:
1. Glycol set point: Ensure you see SET in the display screen.
a. You can change options from SET, INFO and POWER by using the UP and DOWN
buttons.
b. Press ENTER to navigate tothe glycol temperature set screen.
c. Press ENTER again to navigate to the numerical readout. Use UP and DOWN buttons to
adjust todesired setpoint.
2. Pump pressure set point: Ensure you see SET in the display screen.
a. Press DOWN until you see pump pressure set point.
b. Press ENTER button tonavigate to numerical readout and adjust with UP and DOWN to
set pump pressure. Please note that pressure setpoints are often preset.
Info screens:
1. Ensure you see INFO in the bottom right portion of the display screen.
2. Press ENTER to navigate to the first of nine information screens.
3. Use DOWN to scroll through the information screens.
Alarms:
1. Press ALARM.
2. Navigate with UP and DOWN to see current alarms.
a. To clear the alarms, press UP or DOWN through alarm screen until you see a prompt
saying “press Alarm button for 3 seconds.”
:UP

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Carel Alarms
CODE
DESCRIPTION
RESET
ACTION
DELAY
AL004
Unit – User inlet water temperature probe
A
Switch the unit off
10s
AL005
Unit – User outlet water temperature probe
A
Switch the unit off
10s
AL008
Unit – User pump 1 overload
M
None
No
AL009
Unit – User pump 2 overload
M
None
No
AL018
Unit – User 1 pump maintenance
A
None
Parameter
A00
AL019
Unit – User 2 pump maintenance
A
None
Parameter
A02
AL022
Unit – High chilled water temperature
A
None
Parameter
A021/A022
AL100
Circuit 1 – Alarm discharge probe pressure
A
Stop circuit 1
10s
AL101
Circuit 1 – Alarm suction probe pressure
A
Stop circuit 1
10s
AL102
Circuit 1 – Alarm discharge probe temperature
A
Stop circuit 1
10s
AL103
Circuit 1 – Alarm suction probe temperature
A
Stop circuit 1
10s
AL105
Circuit 1 Envelope – High compression ratio
A
Stop circuit 1
Parameter
Cb17
AL106
Circuit 1 Envelope – High discharge pressure
M
Stop circuit 1
Parameter
Cb17
AL108
Circuit 1 Envelope – High suction pressure
A
Stop circuit 1
Parameter
Cb17
AL109
Circuit 1 Envelope – Low compression ratio
A
Stop circuit 1
Parameter
Cb17
AL110
Circuit 1 Envelope – Low differential pressure
A
Stop circuit 1
Parameter
Cb18
AL111
Circuit 1 Envelope – Low discharge pressure
A
Stop circuit 1
Parameter
Cb17
AL112
Circuit 1 Envelope – Low suction pressure
A
Stop circuit 1
Parameter
Cb17
AL113
Circuit 1 Envelope – High discharge temperature
A
Stop circuit 1
Parameter
Cb17
AL123
Circuit 1 EVD – Offline
A
Stop circuit 1
No
AL165
Circuit 1 – Alarm freeze evaporation
temperature
M
Stop circuit 1
Parameter
A041
AL166
Circuit 1 – Compressor 1 maintenance
A
None
Parameter
Ca00
AL167
Circuit 1 – Compressor 2 maintenance
A
None
Parameter
Ca02
AL173
Circuit 1 – High pressure alarm by pressure
switch
M
Stop circuit 1
No
AL174
Circuit 1 – Low pressure alarm by pressure
switch
R
Stop circuit 1
Parameter
Ca19/Ca20
AL175
Circuit 1 – Overload compressor 1
M
Stop compr.1 Circ.1
No

INSTALLATION GUIDE • USER MANUAL
AL176
Circuit 1 – Overload compressor 2
M
Stop compr.2 Circ.1
No
AL178
Circuit 1 – Pump-Down end for maximum time
A
Stop circuit 1
Parameter
B035
AL200
Circuit 2 – Alarm discharge probe pressure
A
Stop circuit 2
10s
AL201
Circuit 2 – Alarm suction probe pressure
A
Stop circuit 2
10s
AL202
Circuit 2 – Alarm discharge probe temperature
A
Stop circuit 2
10s
AL203
Circuit 2 – Alarm suction probe temperature
A
Stop circuit 2
10s
AL205
Circuit 2 Envelope – High compression ratio
A
Stop circuit 2
Parameter
Cb17
AL206
Circuit 2 Envelope – High discharge pressure
M
Stop circuit 2
Parameter
Cb17
AL208
Circuit 2 Envelope – High suction pressure
A
Stop circuit 2
Parameter
Cb17
AL209
Circuit 2 Envelope – Low compression ratio
A
Stop circuit 2
Parameter
Cb17
AL210
Circuit 2 Envelope – Low differential pressure
A
Stop circuit 2
Parameter
Cb18
AL211
Circuit 2 Envelope – Low discharge pressure
A
Stop circuit 2
Parameter
Cb17
AL212
Circuit 2 Envelope – Low suction pressure
A
Stop circuit 2
Parameter
Cb17
AL213
Circuit 2 Envelope – High discharge temperature
A
Stop circuit 2
Parameter
Cb17
AL223
Circuit 2 EVD – Offline
A
Stop circuit 2
No
AL265
Circuit 2 – Alarm freeze evaporation
temperature
M
Stop circuit 2
Parameter
A041
AL266
Circuit 2 – Compressor 1 maintenance
A
None
Parameter
Ca00
AL267
Circuit 2 – Compressor 2 maintenance
A
None
Parameter
Ca02
AL273
Circuit 2 – High pressure alarm by pressure
switch
M
Stop circuit 2
No
AL274
Circuit 2 – Low pressure alarm by pressure
switch
R
Stop circuit 2
Parameter
Ca19/Ca20
AL275
Circuit 2 – Overload compressor 1
M
Stop compr.1 Circ.2
No
AL276
Circuit 2 – Overload compressor 2
M
Stop compr.2 Circ.2
No
AL278
Circuit 2 – Pump-Down end for maximum time
A
Stop circuit 2
Parameter
B035
Reset:
A: automatic reset
M: manual reset
R: Automatic reset with retries
GD-20H & GD-27H MODELS

9EasyStepstoStart‐upYourNewG&DChiller
Pleaseviewinstallvideosonlineatwww.gdchillers.com/installation‐videos
ChillerModels20H,27H,20H‐MS,&27H‐MS
1. Chillermustbepositionedwithat least 30 inches of clearance on air intake side(oppositelouveredaccess
panels)and open to free air on exhaust side(louveredpanelside)with no obstructions.Adequate clearance
for airflow must be provided for the chiller to operate reliably. Refer to the figure CHILLER CLEARANCE
REQUIREMENTS for more details.
2. InstallY‐strainer(required)orpurgevalveonreturnlineatchiller.
3. WiththedoorswitchesintheOFFposition,ensureallbreakersareintheONposition.Thechillermustthenbe
suppliedwithpowerforatleast4hours.Verifythereisavisibleoillevelincompressorsightglassesbefore
proceeding.
4. Flushallpipinglines:
a. Ensurechillerstart/stopdoorswitchremainsintheOFFposition.
b. TurncontrolpowerdoorswitchON,thenprocesspumpdoorswitchONandverifycorrectpump
rotation.Proceedwithflushingthesystem.Oncealldebrishasbeenflushedfromthesystem,remove
asmuchwaterfromsystemaspossible.
5. Fillreservoir/loopwith35%propyleneglycol.Temporarilyclosethesupplyvalve.Confirmglycolpressure
shows20PSIusingboththeCarelcontrollerandthemanualpressuregaugelocatedontheprocesspump
dischargeline.
6. Openthesupplyvalve,andcirculateglycolthroughtheentireloopforatleast30minutes.Re‐verifyglycol
mixtureusingarefractometer.TheglycolmixtureMUSTbe35to40%.Correctasneededbeforeproceeding.
Re‐verifyoillevelincompressorsightglassesbeforeproceeding.Donotproceedunlessthereisavisibleoil
levelinthecompressorsightglass.
7. Openallservicevalvesinchillermarkedwithtags.Topreventirreversibledamage,bottomvalveon
compressormustbecrackedbackin½to1fullturnafterbeingfullyopened.Contactusformoredetailsas
needed:800‐555‐0973.
8. Turnchillerstart/stopdoorswitchtotheRUNposition.Compressorsshouldstarttorun.Fanstofollowshortly.
9. AdjustingsetpointsonCarelcontroller:Presstheup/downarrowsuntilSETdisplaysinbottomrightcorner.
Pressenterandchangethetemperaturetodesiredsetpoint.IfprocesspumpisequippedwithVFD,pressure
settingsfortheVFDcanbeadjustedhereaswell.
PLEASEVISITGDCHILLERS.COMTOVIEWOURINSTALLATIONVIDEOS&FAQS
*G&DChillerswelcomesanyandallquestionsorconcerns.Wecanbereachedat800‐555‐0973or541‐345‐3903
GD‐9ES_20‐27H‐MS_CRL‐r2021b

INSTALLATION GUIDE •USER MANUAL SINGLE & DUAL STAGE MODELS
9
G&D CHILLERS, INC. •GD-MNL_SD_CM-R2021A
WARRANTY START-UP CHECKLIST
G&D CHILLERS, INC.
13
Jobsite:
Tech Company:
Chiller Model:
Technician:
Chiller Serial #:
Start-Up Date:
FOLLOWING START-UP OF CHILLER, PLEASE SEND A COPY OF COMPELTED FORM TO G&D TECH SUPPORT
CLEARANCE AROUND
CHILLER
(Include picture if necessary)
FRONT:
BACK:
LEFT:
RIGHT:
GLYCOL MIXTURE (35%)
GLYCOL LEVEL
(Reservoir % Full)
PHASE/VOLTAGE
VOLTAGE TO GROUND
(Note: High Leg to L2)
L1:
L2:
L3:
PUMP ROTATION
GLYCOL PRESSURE
COMPRESSOR A
COMPRESSOR B
COMPRESSOR C
COMPRESSOR D
CRANK CASE HEATER
ENGERGIZED 4 HOURS
COMPRESSOR OIL
LEVEL
MOTOR AMPS:
L1:
L1:
L1:
L1:
L2:
L2:
L2:
L2:
L3:
L3:
L3:
L3:
SUPERHEAT (°F)
SUBCOOLING (°F)
SUCTION PRESSURE @
30 °F GLYCOL TEMP.
DISCHARGE PRESSURE
@ 30°F GLYCOL TEMP.
PUMP #1
PUMP #2
PUMP #3
PUMP #4
MOTOR AMPS:
L1:
L1:
L1:
L1:
L2:
L2:
L2:
L2:
L3:
L3:
L3:
L3:
FAN MOTOR #1
FAN MOTOR #2
FAN MOTOR #3
FAN MOTOR #4
MOTOR AMPS:
L1:
L1:
L1:
L1:
L2:
L2:
L2:
L2:
L3:
L3:
L3:
L3:
FAN MOTOR #5
FAN MOTOR #6
FAN MOTOR #7
FAN MOTOR #8
MOTOR AMPS:
L1:
L1:
L1:
L1:
L2:
L2:
L2:
L2:
L3:
L3:
L3:
L3:
AMBIENT TEMP @
STARTUP

I
14
SEQUENCE OF OPERATION
1. Chiller supply and return ball valves should
always be open during normal operation.
2. Fluid bypass valve is factory set at 20 PSI valve
design to allow minimum flow across heat
exchanger when process is not calling for cooling.
3. Pump circulates at all times when panel door
switch is in the Run position.
4. Compressor control circuit is energized when
pump is running.
5. If pump fails or flow fails compressor control
circuit will de-energize.
6. Programmable logic controller (PLC) energizes
Electronic Expansion Valve (EEV) based on
leaving fluid temperature.
7. The controller will energize the compressor
starter while monitoring system pressures and
flow.
8. If all parameters remain in a safe range, the
compressor will continue torununtil the
thermostatic logic detects that it is no longer
needed.
9. The EEV will close, the compressor will pump
down and stop.
10. Door switch will pump down compressor then
turn off pump if switch is shut off during
compressor run cycle.
11. Line voltage power should be left on to main
terminal block atall times to keep crank case
heater energized during extended off cycles.
MAINTENANCE
Please contact G&D Technical Support if you have any questions or concerns regarding the performance, operation,
or maintenance of your chiller: 800-555-0973
•Refer to the separate G&D Chillers Preventive Maintenance Checklist for a complete list of maintenance tasks.
•Contract a licensed refrigeration technician to evaluate the chiller refrigeration circuit(s) regularly. These
checkups should occur annually at a minimum. Every 3-6 months is recommended.
The following tasks can be performed without the need for specialized equipment or training:
•Check glycol level and glycol/water ratio monthly. Use glycol refractometer to confirm 35% glycol mixture.
•Check compressor oil in sight glass at bottom of compressor monthly. Inspect for any oil leaks.
•Verify pump function quarterly. Confirm glycol supply pressure. Listen for abnormal sounds from the pump.
•Verify thermostat function quarterly. Check displayed temperature against a thermometer measurement.
•Condenser should be cleaned at least every 6 months for proper operation and efficiency. Use a garden hose
and spray at an angle downward. If in a dirty environment, cleaning may be needed more often.
•Lubricate fan motors every 12 months.
•See warning below. With the service disconnect in the OFF position (no power to the chiller), inspect control
panel contacts on compressor and pump contactors. Contact an electrician if replacements are needed.
WARNING: DO NOT ATTEMPT TO SERVICE ELECTRICAL COMPONENTS OR MAKE ADJUSTMENTS IN ELECTRICAL
PANEL WITHOUT PROPER TRAINING AND IMPLEMENTATION OF LOCKOUT/TAG-OUT SAFETY PROCEDURES

INSTALLATION GUIDE •USER MANUAL
15
TROUBLESHOOTING
COMPLAINT
SYMPTOMS
CAUSE
SOLUTION
1 System short of
capacity
Lower than expected suction
and discharge pressures
Low refrigerant charge
Check for leaks, repair, and
recharge. See item 5
Higher than expected
head pressure
Dirty condenser
Clean. See item 2
Lower than normal suction
pressure
Incorrect superheat -
too high
Adjust superheat
2 Head pressure
too high
Tripping high pressure switch, or
compressor trips on internal
overload
Dirty condenser
Clean condenser
Condenser air short
circuiting or location
too hot
Remove obstructions,
causes for air short circuiting
Defective condenser fan
motor or blade
Replace
Air or non-condensable
gases in the system
Purge the system
Refrigerant over charge
Remove excess refrigerant
3 Head pressure
too low
Sight glass with bubbles
Refrigerant leak or system
undercharged
Check for leaks, repair
and recharge
Plugged filter drier
Replace filter drier
Insufficient subcooling
Check condenser subcooling
circuit
4 Suction pressure
too high
Glycol temperature will not
reach set point
Excessive load on the
system
Check load and improve
conditions
Incorrect superheat
TEV stuck open due to
ice or defect
Check, repair, or re-
place TEV
Incorrect superheat setting
of the expansion valve
Adjust superheat
5 Suction pressure
too low
Sight glass with bubbles
See item 3
See item 3
Warm suction line, signs of
frost on the TEV and low
system capacity
Plugged TEV or strainer
Clean TEV and strainer
Compressor cycling due to
low pressure cutout
See item 12
See item 12
6 Noisy
compressor
Oil level below midpoint of the
compressor sight glass during
operation
Lack of oil
Avoid compressor short
cycling or run compressor
enough to return oil to
crankcase, correct low load
conditions. Add oil.
Noticeable knock in
compressor
Worn or scored bearings
Replace the compressor
Frosted suction line and
compressor shell
Liquid flood back
Check superheat and TEV
operation
GD-20H & GD-27H MODELS
G&D CHILLERS, INC. •GD-20-27H-MS_CRL-r2021A

I
16
TROUBLESHOOTING
COMPLAINT
SYMPTOMS
CAUSE
SOLUTION
7 Compressor does
not pump
Minimal difference in pressure
between high side and low side
of system, when compressor
motor has power
Broken suction valves
Change compressor
Broken discharge line
Change compressor
Internal pressure safety
valve stuck open
Check item 13 and change
compressor if
necessary
8 Compressor will
not start
Blown fuse or open disconnect
Short circuit or other
electrical failure
Check electrical circuit
and wiring
Tripped or damaged overload
Overheating or overcurrent
Wait 2-3 hours for overload
to reset and check
refrigerant charge or power
quality to the compressor
Open pressure switch
Loss of refrigerant
charge
Check for leaks, repair
and recharge
Loose wires
Vibration, bad crimping or
under-torque
Check terminals at
compressor, contactor and
wiring in general
Motor seized
Low oil level or phase
reversal
Check oil level. Restart 3-ph
compressor by switching
2 phases; replace if it does not
restart
9 Compressor starts
but start relay does
not drop out
High running current,
overload trips
Incorrect wiring of start
components
Check wiring
Incorrect or defective
start relay
Confirm operation, model
and make
Incorrect or defective start
capacitor
Confirm integrity and
specs, check if fitted with
discharge resistance
Incorrect or defective
run capacitor
Confirm integrity and
specs
Low voltage
Fix undervoltage protection
10 Compressor
runs but cuts
out on
overload
Internal overload tripping
MUST WAIT 2-3 HOURS TO
CHECK IF IT WILL RESET
Excessive head pressure
due to dirty condenser
or lack of condenser air
or water flow
See item 2 above
Low voltage or unbalanced
Fix undervoltage protection
Faulty electrical connections
causing single phasing or
high current surges
Remake the connections
Sticking start relay on
single phase machines
leaving start cap on circuit
Replace relay and ensure start
cap is fitted with a discharge
resistance

INSTALLATION GUIDE •USER MANUAL
17
TROUBLESHOOTING
COMPLAINT
SYMPTOMS
CAUSE
SOLUTION
11 Compressor starts
but cycles on
overload
Internal overload tripping
MUST WAIT 2-3 HOURS TO
CHECK IF IT WILL RESET
Loss of charge causing
insufficient motor cooling
Check for leaks, repair, and
recharge
Voltage is low or
unbalanced if 3-ph
1-ph fix undervoltage
protection, 3-ph correct
phase imbalance
Defective or wrong run
cap
Check and replace
Defective overload
Check current and re-
place compressor if
necessary
12 Compressor
runs but
cycles on…
…overload
See items 10 and 11
See items 10 and 11
…thermostat
Thermostat differential
set too close
Check and widen differential
…high pressure switch
See item 2
See item 2
---low pressure switch
See items 3 and 5 See items 3 and 5
Leaking liquid line solenoid
valve (LLSV)
Replace LLSV
Leaking compressor
valves
Replace compressor
Undercharged system
Check for leaks and
recharge
13 Internal
pressure
safety valve
(IPRV) opens
Refrigerant trapped in
compressor
Discharge service valve
closed
Open discharge service
valve
Discharge pressure exceeds high
pressure setting
High pressure switch
malfunction
Reset or replace high
pressure switch, see item 2
14 Will not start,
trips on
overload
Start relay damaged or
burned out
Too low or too high line
voltage
Correct and replace relay
Incorrect wiring
Replace relay and rewire per
compressor wiring diagram
Excessive cycling See item 11
GD-20H & GD-27H MODELS
G&D CHILLERS, INC. •GD-20-27H-MS_CRL-r2021A

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INSTALLATION GUIDE •USER MANUAL
19
WARRANTY STATEMENT
TWO-YEAR LIMITED WARRANTY ON PARTS, ONE-YEAR LIMITED WARRANTY ON LABOR
G&D CHILLERS, INC. provides a limited warranty to the original purchaser of new products against defects in
materials and workmanship for a period of one (1) year of normal commercial usage. For the subsequent period of
one (1) year of normal commercial usage immediately following the first, this warranty is extended to cover parts
only. This warranty is not transferable. If a product covered by this warranty is determined to be defective within
the applicable warranty periods, G&D CHILLERS, INC. will, unless otherwise required by applicable law, either repair
or exchange the product at its sole option and discretion.
EXCHANGE
Should G&D CHILLERS, INC. elect to exchange a product due to a covered defect during the warranty period, the
replacement unit may, at G&D CHILLERS, INC.’s sole option and discretion, be new or one which has been recertified,
reconditioned, refurbished or otherwise remanufactured from new or used parts and is functionally equivalent to
the original product.
REPAIR: PARTS AND LABOR
There will be no charge for parts or labor to repair a product for a covered defect during the applicable warranty
periods. Replacement parts may, at G&D CHILLERS, INC.’s sole option and discretion, be new, used, reconditioned,
refurbished or otherwise remanufactured or recertified as functionally equivalent replacement parts.
REMAINING WARRANTY
Repaired or exchanged products are warranted for the remaining portion of the product’s original warranty or for
ninety (90) days from warranty service or exchange, whichever is longer. Any upgrade to the original product will be
covered only for the duration of the original warranty period.
EXCLUSIONS
This warranty does not cover, for example: abuse, accident, acts of God, consumable parts such as batteries,
cosmetic damage (e.g. scratches, dents, cracks), damage caused by use with non-G&D CHILLERS, INC. products (e.g.
accessories, housing, parts, etc.), damages from shipping, improper installation or operation, improper voltage
supply or power surges, lack of reasonable use, misuse, modifications or alterations, normal wear and tear or aging,
as well as installation and set-up issues or any tampering or repairs attempted by anyone other than by a G&D
CHILLERS, INC. authorized repair technician. This limited warranty does not cover products sold “AS IS”, “FACTORY
RECERTIFIED”, or by a non-authorized reseller.
ASSIGNMENT OF WARRANTIES
G&D CHILLERS, INC. assigns to product purchasers any and all warranties of manufacturers and suppliers of
component parts that are assignable, but G&D CHILLERS, INC. makes no representations as to the effectiveness or
extent of such warranties and assumes no liability or responsibility for any third-party manufacturer or supplier’s
products or component parts that are sold by G&D CHILLERS, INC.
DISCLAIMER OF WARRANTY
THERE ARE NO EXPRESS WARRANTIES OTHER THAN THOSE LISTED OR DESCRIBED ABOVE. EXCEPT AS SPECIFIED IN
THIS WARRANTY SECTION, ALL EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS, AND WARRANTIES
INCLUDING, WITHOUT LIMITATION, ANY IMPLIED WARRANTY OR CONDITION OF MERCHANTABILITY, FITNESS FOR
A PARTICULAR PURPOSE, OR ARISING FROM A COURSE OF DEALING, LAW, USAGE, OR TRADE PRACTICE, ARE HEREBY
EXCLUDED TO THE EXTENT ALLOWED BY APPLICABLE LAW AND ARE EXPRESSLY DISCLAIMED BY G&D CHILLERS, INC.
**TO ACTIVATE WARRANTY, FILL OUT STARTUP CHECKLIST AND RETURN WITHIN 30 DAYS**
GD-20H & GD-27H MODELS
G&D CHILLERS, INC. •GD-20-27H-MS_CRL-r2021A

I
20
TO THE EXTENT THAT ANY OF THE SAME CANNOT BE EXCLUDED, SUCH IMPLIED CONDITION, REPRESENTATION
AND/OR WARRANTY IS LIMITED IN DURATION TO THE EXPRESS WARRANTY PERIOD REFERRED TO IN THE "LIMITED
WARRANTY" SECTION ABOVE. BECAUSE SOME STATES OR JURISDICTIONS DO NOT ALLOW LIMITATIONS ON HOW
LONG AN IMPLIED WARRANTY LASTS, THE ABOVE LIMITATION MAY NOT APPLY IN SUCH STATES. THIS WARRANTY
GIVES THE CUSTOMER SPECIFIC LEGAL RIGHTS, AND THE CUSTOMER MAY ALSO HAVE OTHER RIGHTS WHICH VARY
FROM JURISDICTION TO JURISDICTION.
DISCLAIMER OF LIABILITY
G&D CHILLERS, INC.'S TOTAL LIABILITY FOR ANY AND ALL LOSSES AND DAMAGES RESULTING FROM ANY CAUSE
WHATSOEVER INCLUDING G&D CHILLERS, INC.’S NEGLIGENCE, ALLEGED DAMAGE, OR DEFECTIVE GOODS, WHETHER
SUCH DEFECTS ARE DISCOVERABLE OR LATENT, SHALL IN NO EVENT EXCEED THE PURCHASE PRICE OF THE PRODUCT.
G&D CHILLERS, INC. SHALL NOT BE RESPONSIBLE FOR LOSS OF USE, WORK STOPPAGE, FAILURE OF OTHER
EQUIPMENT TO WHICH THE PRODUCT IS CONNECTED, COMMERCIAL LOSS, LOST REVENUE OR LOST PROFITS, LOSS
OF GOODWILL, LOSS OF REPUTATION, OR OTHER INCIDENTAL OR CONSEQUENTIAL DAMAGES. NO ORAL OR
WRITTEN REPRESENTATIONS MADE BY G&D CHILLERS, INC. SHALL CREATE ANY ADDITIONAL WARANTY
OBLIGATIONS, INCREASE THE SCOPE, OR OTHERWISE MODIFY IN ANY MANNER THE TERMS OF THIS LIMITED
WARRANTY. TO THE EXTENT PERMITTED BY APPLICABLE LAW, G&D CHILLERS, INC. DOES NOT WARRANT THAT THE
OPERATION OF ANY PRODUCTS COVERED UNDER THIS LIMITED WARRANTY WILL MEET YOUR REQUIREMENTS, OR
THIRD PARTY SERVICES, BE UNINTERRUPTED, ERROR-FREE, OR THAT DEFECTS IN THE PRODUCTS WILL BE
CORRECTED. SOME STATES DO NOT ALLOW THE EXCLUSION OF INCIDENTAL OR CONSEQUENTIAL DAMAGES, SO THE
ABOVE LIMITATIONS OR EXCLUSIONS MAY NOT APPLY TO YOU. THIS WARRANTY GIVES YOU SPECIFIC LEGAL RIGHTS,
AND YOU MAY ALSO HAVE OTHER RIGHTS, WHICH VARY FROM STATE TO STATE. THIS LIMITED WARRANTY IS
SUBJECT TO CHANGE WITHOUT NOTICE. CHECK www.gdchillers.com FOR THE MOST CURRENT VERSION OF THIS
WARRANTY.
SEVERABILITY
In the event that any term or provision contained in this limited warranty is found to be invalid, illegal or
unenforceable by a court of competent jurisdiction, then such provision shall be deemed modified to the
extent necessary to make such provision enforceable by such court, taking into account the intent of the
parties. The invalidity in whole or in part of any portion of this limited warranty shall not impair or affect
the validity or enforceability of the remaining provisions of this limited warranty.
HOW TO OBTAIN WARRANTY SERVICE (PRE-AUTHORIZATION REQUIRED)
To obtain warranty service, contact G&D CHILLERS, INC.:
1. Email: [email protected]
2. Phone: [phone] from 9:00AM to 5:00PM Monday through Friday Pacific Time.
3. By mail: G&D Chillers, Inc.
760 Bailey Hill Rd
Eugene, OR 97402