ACS GP20 Guide

<<Insert name of product>><< insert part number>> • << 9/11/2018>> 1
GP SERIES PORTABLE CHILLERS
Part Number: 882.12047.00
Revision: 12/2/2021
OPERATION AND INSTRUCTION MANUAL
GP20, GP30, GP40, GP50, GP70, GP90, GP105, GP140, GP175,
GP210

GP Series Portable Chillers 882.12047.00 • 12/2/2021 ii
Write Down Your Serial Numbers Here For Future Reference:
_________________________ _________________________
_________________________ _________________________
_________________________ _________________________
We are commied to product improvement.
Specicaons, appearance, and dimensions described in this manual are subject to change without
noce.
DCN No. ____________
© Copyright 2023
All rights reserved.

GP Series Portable Chillers 882.12047.00 • 12/2/2021 iii
Shipping Info
Unpacking and Inspection
You should inspect your equipment for possible shipping damage.
Thoroughly check the equipment for any damage that might have occurred in transit, such
as broken or loose wiring and components, loose hardware and mounng screws, etc.
In the Event of Shipping Damage
According to the contract terms and condions of the Carrier, the responsibility of the
Shipper ends at the me and place of shipment.
Nofy the transportaon company’s local agent if you discover damage.
Hold the damaged goods and packing material for the examining agent’s inspecon. Do not
return any goods before the transportaon company’s inspecon and authorizaon.
File a claim with the transportaon company. Substanate the claim by referring to the
agent’s report. A cered copy of our invoice is available upon request. The original Bill of
Lading is aached to our original invoice. If the shipment was prepaid, write us for a
receipted transportaon bill.
Advise customer service regarding your wish for assistance and to obtain an RMA (return
material authorizaon) number.
If the Shipment is Not Complete
Check the packing list as back-ordered items are noted on the packing list. You should have:
Machine
Bill of lading
Packing list
Operang and Installaon packet
Electrical schemac and panel layout drawings
Component instrucon manuals
Re-inspect the container and packing material to see if you missed any smaller items during
unpacking.
If the Shipment is Not Correct
If the shipment is not what you ordered, please contact customer service at 262.641.8600.
Have the order number and item number ready. Hold the items unl you receive shipping
instrucons.

GP Series Portable Chillers 882.12047.00 • 12/2/2021 iv
Returns
Do not return any damaged or incorrect items unl you receive shipping instrucons from
the shipping department.
Disclaimer:
All rights reserved. No part of the contents of this manual may be reproduced, copied, or
transmitted in any form or by any means including graphic, electronic, or mechanical methods or
photocopying, recording, or information storage and retrieval systems without the written
permission of the publisher, ACS Group, unless it is for the purchaser’s personal use. The
information in this manual is subject to change without notice and does not represent a
commitment on the part of ACS Group. Manufacturer reserves the right to change specifications,
design without notification or obligation.
ACS Group does not assume any responsibility for any errors that may appear in this manual. In
no event will ACS Group be liable for technical or editorial omissions made herein, nor for
direct, indirect, special, incidental, or consequential damages resulting from the use or defect of
this manual. The information in this document is not intended to cover all possible conditions
and situations that might occur. The end user must exercise caution and common sense when
installing, using, or maintaining ACS Group products. ACS Group products should only be
installed by qualified, experienced technicians. If any questions or problems arise, call ACS
Groups customer service at 800-423-3183. Any change to an ACS Group product made during
the installation, start-up, or at any other time must be submitted in writing to ACS Group for
approval and be approved by ACS Group in writing prior to commission. The product warranty
is voided when any unapproved change is made to an ACS Group product.

GP Series Portable Chillers 882.12047.00 • 12/2/2021 v
Table of Contents
CHAPTER 1: SAFETY ............................................................................................................. 7
1-1 How to Use This Manual............................................................................................7
Safety Symbols Used in this Manual......................................................................... 8
General Safety Regulations .................................................................................................9
1-2 Responsibility ............................................................................................................9
CHAPTER 2: FUNCTIONAL DESCRIPTION ...................................................................... 13
2-1 Models Covered in This Manual...............................................................................13
2-2 General Description.................................................................................................13
Refrigeration Circuit ...........................................................................................15
2-3 Standard Features...................................................................................................16
2-4 Safety Devices and Interlocks..................................................................................18
2-5 Optional Features ....................................................................................................20
CHAPTER 3: INSTALLATION .............................................................................................. 22
3-1 Uncrating .................................................................................................................22
3-2 Electrical Connections .............................................................................................22
3-4 Bypass Valve Considerations...................................................................................23
3-5 Galvanic Corrosion Considerations..........................................................................24
3-6 Water Treatment Considerations..............................................................................24
3-7 Condenser Considerations ......................................................................................24
3-8 Water Reservoir.......................................................................................................36
3-10 Automatic Water Make-Up Option............................................................................38
3-11 Initial Start-Up..........................................................................................................39
3-12 Finishing Setup: Setting Up Passwords ...................................................................42
3-13 Electrical Connection...............................................................................................44
3-14 Unit Information .......................................................................................................45
3-15 Cold Weather Installation.........................................................................................47
CHAPTER 4: OPERATION .................................................................................................... 48
4-1 Panel Buttons, Indicator Lights, and Switches .........................................................48

GP Series Portable Chillers 882.12047.00 • 12/2/2021 vi
Microprocessor Controller ..................................................................................48
4-2 Initial Start-up ..........................................................................................................49
4-3 Status Screens ........................................................................................................51
4-4 Controller Setpoints .................................................................................................54
4-5 Configuration Settings .............................................................................................59
4-8 Optional Communications........................................................................................62
CHAPTER 5: MAINTENANCE ............................................................................................. 63
5-1 Lubrication...............................................................................................................63
5-2 Filter Cleaning .........................................................................................................63
5-3 Maintaining the Condenser ......................................................................................63
5-4 Maintaining the Evaporator ......................................................................................64
5-5 Evaporator Process Piping Y-Strainer......................................................................64
5-6 Preventative Maintenance Service...........................................................................64
CHAPTER 6: TROUBLESHOOTING.................................................................................... 66
6-1 Identifying the Cause of a Problem ..........................................................................66
CHAPTER 7: APPENDIX....................................................................................................... 78
7-1 7-1 Customer Satisfaction Warranty Program .......................................................78
7-3 Pumps, Curves, Flow, and Pressure Considerations ...............................................93
7-4 Technical Assistance .................................................................................................101

GP Series Portable Chillers 882.12047.00 • 11/15/2021 7
Chapter 1: Safety
1-1 How to Use This Manual
Use this manual as a guide and reference for installing, operating, and maintaining
your machine. The purpose is to assist you in applying efficient, proven techniques
that enhance equipment productivity.
This manual covers only light corrective maintenance. No other maintenance should
be undertaken without first contacting a service engineer.
The Functional Description section outlines models covered, standard features, and
safety features. Additional sections within the manual provide instructions for
installation, pre-operational procedures, operation, preventive maintenance, and
corrective maintenance.
The Installation chapter includes required data for receiving, unpacking, inspecting,
and setup of the machine. We can also provide the assistance of a factory-trained
technician to help train your operator(s) for a nominal charge. This section includes
instructions, checks, and adjustments that should be followed before commencing
with operation of the machine. These instructions are intended to supplement
standard shop procedures performed at shift, daily, and weekly intervals.
The Operation chapter includes a description of electrical and mechanical controls, in
addition to information for operating the machine safely and efficiently.
The Maintenance chapter is intended to serve as a source of detailed assembly and
disassembly instructions for those areas of the equipment requiring service.
Preventive maintenance sections are included to ensure that your machine provides
excellent, long service.
The Troubleshooting chapter serves as a guide for identification of most common
problems. Potential problems are listed, along with possible causes and related
solutions.
The Appendix contains technical specifications, drawings, schematics, parts lists, and
available options. A spare parts list with part numbers specific to your machine is
provided with your shipping paperwork package. Refer to this section for a listing of
spare parts for purchase. Have your serial number and model number ready when
ordering.

GP Series Portable Chillers 882.12047.00 • 11/15/2021 8
Safety Symbols Used in this Manual
The following safety alert symbols are used to alert you to potential personal injury
hazards. Obey all safety messages that follow these symbols to avoid possible injury
or death.
DANGER! DANGER indicates an imminently hazardous situaon that, if not avoided,
will result in death or serious injury.
WARNING! WARNING indicates a potenally hazardous situaon or pracce that, if
not avoided, could result in death or serious injury.
Caution! CAUTION indicates a potenally hazardous situaon or pracce that, if not
avoided, may result in minor or moderate injury or in property damage.

GP Series Portable Chillers 882.12047.00 • 11/15/2021 9
General Safety Regulations
These regulaons should be read, understood and periodically reviewed by all personnel
involved in any way with this machine.
Never operate or remove any machine components that are secured by mechanical
fasteners unless the motor is electrically locked out and all moving parts are moonless.
Do not circumvent the safety interlocks.
Extreme care should be taken to see that all bolts are properly ghtened at all mes during
the operaon of the machine.
1-2 Responsibility
These machines are constructed for maximum operator safety when used under standard
operang condions and when recommended instrucons are followed in the maintenance
and operaon of the machine.
All personnel engaged in the use of the machine should become familiar with its operaon
as described in this manual.
Proper operaon of the machine promotes safety for the operator and all workers in its
vicinity.
Become familiar with materials, inspecon, speed limitaons, guard maintenance, and total
user responsibility while using or servicing the equipment.
Each individual must take responsibility for observing the prescribed safety rules as outlined.
All cauon, warning and danger signs must be observed and obeyed. Any actual or potenal
dangerous condions must be reported to your immediate supervisor.

GP Series Portable Chillers 882.12047.00 • 11/15/2021 10
Figure 1: Safety Tags and Warning Labels

GP Series Portable Chillers 882.12047.00 • 11/15/2021 11
Warnings and Precautions
Our machines are designed to provide safe and reliable operaon when installed and
operated within design specicaons, and follow naonal and local safety codes.
To avoid possible personal injury or equipment damage when installing, operang, or
maintaining this machine, use good judgment and follow these safe pracces:
LEARN AND OBEY your company’s safety policy regarding mechanical and electrical
equipment.
MOVING OR LIFTING THE MACHINE: Although our equipment is built and
engineered for great ruggedness in operaon, care must be taken when moving the
machine along the oor or liing it. Damage may occur to sheet metal covers,
electrical cabinets, or small brackets if pressure is applied to them when moving the
machine. When liing the machine, be certain of total machine weight does not
exceed the capability of the liing equipment.
EQUIPMENT LOCATION: Adequate area for roune maintenance should be provided
in order to open the machine for service. Proper service area clearances also should
allow people who are working on the machine to be clearly visible to others, thereby
reducing the potenal safety hazards.
SAFE HOUSEKEEPING: The work area must be kept clean and uncluered during
periods of operaon or maintenance. No hand tools or other metal objects should
be le on or around the machine.
SAFETY GLASSES OR A FACE SHIELD MUST ALWAYS BE WORN
when servicing or operang the machine.
EAR PROTECTION: The Occupaonal Safety and Health Act of 1970 has established
guidelines for Permissible Noise Exposures (OSHA 1910.95) that should be followed.
EVER aempt to operate the machine unless it is fully assembled with all guards and
interlocks in place and funconal.
OBSERVE all danger, warning, cauon and safety labels on the equipment.
Upon compleon of any machine maintenance, be certain ALL SAFETY GUARDS AND
COVERS are securely and properly fastened prior to resuming machine operaon. All
fasteners must be in place and properly ghtened. ANY SHORTCUTS MAY RESULT IN
INJURY TO PERSONNEL OR DAMAGE TO EQUIPMENT.
NEVER wear any loose ng clothes, neckes, or dangling items such as earrings,
belts, or shoestrings. Jewelry, such as wristwatches, bracelets, or rings should NEVER
be worn. Long hair must be ed back or placed in a ght ng hairnet. NEVER lean

GP Series Portable Chillers 882.12047.00 • 11/15/2021 12
against or rest hands or feet on the equipment when it is in operaon or open for
maintenance. NEVER stand on the machine when it is in operaon.
ALWAYS DISCONNECT AND LOCKOUT the main electrical power to the machine
before performing any service.
SAFETY INTERLOCKS MUST NOT BE BYPASSED. The mechanical and electrical safety
interlocks ensure the safety of personnel. They should never be tampered with or
removed for ANY reason. They should be checked frequently by a qualied mechanic
for proper operaon.
NEVER modify the machine conguraon or any individual component without
wrien noce from the factory.
We have long recognized the importance of safety and have designed and manufactured our
equipment with operator safety as a prime consideraon. We expect you, as a user, to abide
by the foregoing recommendaons in order to make operator safety a reality.

GP Series Portable Chillers 882.12047.00 • 11/15/2021 13
Chapter 2: Functional Description
2-1 Models Covered in This Manual
This manual provides operaon, installaon, and maintenance instrucons for air-, water-and
remote air-cooled portable chillers. Model numbers are listed on the serial tag. Make sure you know
the model and serial number of your equipment before contacng the manufacturer for parts or
service.
Our portable chiller models are designated by approximate output in kW of cooling (20, 30, 40, 50,
through 210) and the cooling method used: -A for air-cooled, -W for water-cooled, and –R for
remote-air cooled.
2-2 General Description
Our portable chillers are reliable, accurate, and easy to use process cooling units. They are available
in air-, water-, and remote air-cooled designs in a range of sizes from 20 kW through 210 kW (5
through 60 tons of refrigeraon). All are self-contained, fully portable and shipped ready to use.
(Remote air-cooled chillers require eld installaon by qualied technicians.) In the standard
conguraon the chiller basically consists of a pump, tank, compressor, condenser, evaporator, and a
control plaorm. All of these components, plus the other integral components to maintain the
leaving uid temperature, are described throughout this Chapter as well as Chapters 3 and 4.
Standard range of operaon is 20ºF to 80ºF (-7ºC to 27ºC) for applicaons using a water/glycol mix
and 45ºF to 80ºF (7º to 27ºC) for water only applicaons.
Typical Applications
This series of portable chillers can be used in any applicaon that needs a constant source of cool
process water. Typical applicaons include, but are not limited to, the following:
•Injecon molding
•Blow molding
•Extrusion
•Thermoforming
•Machine tool
•Metal plang
•Thermal spray
•Aer-coolers (air compressors, dryers, etc.)
•Laser
•Prinng (oset, gravure, digita)
System Limitations
These packaged chillers should be chosen using the following criteria:
Process heat load – Choose the size of the chiller so that rated capacity is no greater than 10% more
than the process heat load.

GP Series Portable Chillers 882.12047.00 • 11/15/2021 14
Process Fluid Temperature – The standard range for the leaving uid temperature for this series of
packaged chillers is 20°F to 80°F (-6.7°C to 26.7°C). When the process requires uid temperatures
below 45°F (27.2°C) it is imperave that the process uid is a mix of an industrial grade ethylene or
propylene glycol and water to the proper percentage (by volume) to protect the system. See
Chapter 3 for a further discussion regarding the use of glycol within the system for these
applicaons.
ACS Group does not warrant the freeze up of the evaporator under any
circumstances.
Chilled Water Circuit
Cooling water “To Process” and “From Process” connecons are
made at the female NPT couplings provided outside the unit.
Warm coolant (water and glycol mixture) returns from
the process and goes into the reservoir tank.
The coolant is then pumped through the evaporator
where it is cooled.
The coolant ows to the process and returns to repeat
the cycle.
A process water bypass valve located between the supply line
and reservoir tank (single pump models only) allows minimal
ow through the unit during the intermient uctuang ow
condions. It is not intended to provide connuous full bypass
ow.
This minimal ow allows the ow switch to make when the process ow is stopped. If the ow
switch is not made the controller shuts down the compressor to prevent freezing up the evaporator.

GP Series Portable Chillers 882.12047.00 • 11/15/2021 15
Refrigeration Circuit
Air-, water-, and remote air-cooled refrigerant condensing dier only in the way the compressed gas
is condensed to a liquid. Shown below is a water-cooled version.
The refrigerant is compressed in the compressor and ows
through the discharge line as a gas to the condenser.
There it gives up its heat as it condenses to a liquid in the
condenser.
Liquid refrigerant from the condenser heat exchanger owing in
the liquid line passes through a shut-o valve into a lter/dryer that
removes moisture and other contaminants. Aer the lter/dryer the
refrigerant passes through a solenoid valve to prevent liquid
migraon when the compressor is o. A refrigerant sight glass is
provided to view the ow of liquid refrigerant, and to view if the
system is free of moisture. The refrigerant then passes through the
thermal expansion valve, which allows the refrigerant to expand (boil
o) and cool (remove the heat from) the uid inside of the
evaporator.
From the evaporator the refrigerant gas ows through the
sucon line back into the compressor.
A modulang electronic hot gas bypass valve is used to control cooling capacity during intermient
or paral load condions. This feature contributes substanally to chiller longevity by eliminang
excessive cycling of the compressor and providing close temperature control.
System Control
Pung this all together, the controller maintains the desired leaving uid temperature using mulple
inputs to determine if, when and for how long the compressor(s) are on, and if, when, the percent
open and for how long the modeling hot gas bypass valve is on.
Once the unit’s power is enabled and the controller is turned on (see Chapter 4 for more details on
the operaon of the controller) it veries there is sucient uid level in the tank (if present). If
there is not enough uid in the tank the controller will warn the user, or ll the tank with water from
a connected source if equipped with the oponal automac water makeup valve. See Chapter 3 for
more informaon regarding the inial setup and startup of the unit.
Once the tank level is sased and the start buon is pressed, the process pump turns on and
provides ow to the process. The controller veries the ow through the electronic ow switch. If
the ow is not established within 10 seconds the controller will alarm and disable the refrigeraon
circuit. Upon ow vericaon the controller uses the leaving uid temperature and the setpoint
temperature to determine the operaon of the compressor(s). When the leaving uid temperature
is greater than the setpoint plus the “compressor on

GP Series Portable Chillers 882.12047.00 • 11/15/2021 16
dierenal” value the controller will enable the compressor; if equipped with two compressors the
controller will enable the one with the least amount of hours. The second compressor will be
enabled if the leaving uid temperature remains above the setpoint plus the “compressor on
dierenal” value for more than 60 seconds.
The hot gas valve is designed to trim the load of one compressor and will modulate in order to meet
the desired leaving uid setpoint via a PID algorithm. Aer the compressor starts, the hot gas valve
is allowed to modulate. The compressor will shut o if the leaving uid temperature drops below
the “compressor o dierenal” and the hot gas valve is at 100% for the “compressor o delay”
me. The hot gas will reset to 0% when the compressor is o. There is a “compressor ancyle” mer
that will delay the me between compressor starts to prevent short cycling of the compressor. This
is a start to start mer set at 5 minutes. For example, if the compressor has been running for 5
minutes and shuts o, then the compressor can start immediately if the demand is there. If it has
only been running for 2 minutes, then it would not be able to start again for 3 minutes.
For a unit with two compressors, the second compressor or lag compressor starts when the lead
compressor is on, the hot gas is at 0%, and the leaving uid temperature is above the setpoint plus
the “compressor on dierenal”. There is also an adjustable “lag compressor on delay” mer.
Before starng either compressor, the compressor with the least amount of runme hours is
considered the lead compressor and the rst to start. When both compressors are running, the
compressor with the most hours is considered the lead compressor and is the rst to stop. The lead
compressor will shut o if the leaving uid temperature drops below the “compressor o
dierenal” and the hot gas valve is at 100% for the “lead compressor o delay” me. The
compressor an-cycle mers are acve with the two compressor units.
There will be two PID controls running simultaneously for determining the posion of the hot gas
valve. One PID output will be based on leaving uid temperature and the other based on a
minimum saturated sucon temperature for freeze protecon. The hot gas valve posion will be
determined by which output is greater. If it is controlling to the saturated sucon temperature to
prevent freezing, a warning will display on the screen that the hot gas is in this mode. Once the
control goes back to setpoint control, the warning will disappear. The saturated sucon temperature
is calculated from the sucon pressure and the type of refrigerant.
The discharge pressure is controlled using an analog output signal to drive a fan for air-cooled units
or a water regulang valve for water-cooled units. The output signal is determined from a PID
algorithm using a discharge pressure transducer as the process variable. The VFD or water
regulang valve is controlled from the analog output to an adjustable discharge pressure setpoint.
The analog output starts at the inial “discharge pressure start” % for a given me delay (discharge
pressure hold). Aer the me delay, it will control to the discharge pressure setpoint via the PID
control. There is also a seng to control the discharge pressure to the most ecient value.
2-3 Standard Features
Mechanical Features
Compressor – Hermec scroll compressors.
Evaporator – Stainless steel copper brazed plate evaporators.

GP Series Portable Chillers 882.12047.00 • 11/15/2021 17
Air-Cooled Condenser – Micro Channel with washable lters, packaged units only. Variable speed
fan control standard for all remote air cooled condensers and GPAC70 through 210. Oponal on
GPAC20 through 50.
Water-Cooled Condenser – Tube-in-tube condensers (GPWC20 – GPWC50), Shell-and-tube
condensers (GPWC70 – GPWC210). All come with electronic cooling water regulang valves.
Remote Air-Cooled Condenser– Micro Channel with low ambient control down to
–20ºF (-29ºC) via variable-speed fan(s).
Variable Speed Fan – GPAC20-50. Reduces the speed of the fan based on refrigerant pressure and
system load, allowing the chiller to operate in ambient temperatures below 75ºF (24ºC). This opon
will also reduce fan noise in lower ambient temperatures and low loads.
Reservoir – GP20 and GP30 models use a 20 gallon (75 liter) polyethylene tank, GP40 and GP50
models use a 40 gallon (150 liter) polyethylene tank, GP70 thru GP105 models use a 70 gallon (265
liter) polyethylene tank, GP140 thru GP210 models use a 140 gallon (530 liter) polyethylene tank.
304SS is available as an opon for all sizes. (Tank size is approximate).
Piping – Non-ferrous chilled water piping
Pump – ODP motors (TEFC Oponal)—horizontally mounted stamped stainless steel construcon.
Other Mechanical Features
Low process water thermal ow switch
NEMA-rated fan motor(s) on air-cooled models
Galvanized structural steel frame, polyester powder coat painted cabinetry
Internal process water bypass valve for system protecon only
Fully insulated refrigeraon and process water piping
20 mesh Y strainer on process water piping into the evaporator
Tank level indicaon via operator interface
Pump pressure indicaon via operator interface
Electrical Features
Fully accessible NEMA 4/12-style electrical control enclosure
Single-point power and ground connecon
Non-fused disconnect switch, lockable
Branch circuit protecon
208-230/3/60, 460/3/60, 575/3/60 volt; 400/3/50 volt
Refrigeration Features
HFC-410a refrigerant
Electronic modulang hot gas bypass capacity control
High refrigerant pressure cutout switch (manual reset)

GP Series Portable Chillers 882.12047.00 • 11/15/2021 18
Sucon and discharge pressure transducers.
High refrigerant pressure spring actuated relief valve
Mulple refrigeraon access ports
Liquid line shut-o ball valves
Filter-dryer
Sight glass
Externally equalized thermal expansion valve
Liquid line solenoid
Compressor crankcase heater
Controller Features
O-the-shelf microprocessor-based PID controller with To Process, From Process and Set Point
readout
Time delay for proof of water ow/pressure (models w/pump only)
Low refrigerant pressure me delay for low ambient start-up on remote air-cooled and air-
cooled chillers with the variable-speed fan opon.
8 line x 22 character display with status, alarm, and service screens
Display has magnec back and can be mounted anywhere.
Other Features
One year labor warranty and one year compressor warranty
Two year parts warranty
Three year limited controller warranty
2-4 Safety Devices and Interlocks
Protect the system from freezing with inhibited industrial grade glycol 20ºF below the
leaving water temperature set point. Condensaon may form inside the pump tank
and dilute the mixture, therefore the freezing point should be veried periodically. See
Figure 6 on page 18 for the correct mixture.
Crankcase Heater
All of the chillers are equipped with a compressor crankcase heater. It is wired through the control
transformer that operates connuously whenever power is applied to the chiller, and the
compressors are o.
Energize the crankcase heater for at least 24 hours before inial startup to drive
dissolved refrigerant from the compressor oil. Failure to do so will damage the
compressor. If unit is mounted outdoors, power to the unit (and the main power
switch) must remain on 24 hours per day, 7 days per week to prevent liquid migraon
to the compressor.

GP Series Portable Chillers 882.12047.00 • 11/15/2021 19
High Pressure Cutout
This electro-mechanical cutout device opens the compressor control circuit if the refrigeraon
system compressor discharge pressure exceeds 575 psig.
The high-pressure cutout is a manual reset device typically mounted on the compressor
discharge line inside the mechanical cabinet. Call a refrigeraon service technician to
analyze the problem and reset the control.
Typical GPAC-20
Low Pressure Cutout (no switch but done through the transducer)
There are two pressure transducers in the refrigeraon piping – one on the sucon line before the
compressor and one on the discharge line aer the compressor. Within the program there are four
sengs that warn and fault based on these two pressure transducers. The low sucon pressure
warning and fault are calculated based on the Freeze Point value entered into the controller. The
low discharge warning is set for 200 psig (1,379 kPa), and the compressor will fault at 180 psig (1,241
kPa). To prevent nuisance tripping there are delays built in to the program.
Call a refrigeraon service technician to analyze the problem to prevent recurring low
pressure faults.
Note:
High pressure cutout

GP Series Portable Chillers 882.12047.00 • 11/15/2021 20
Flow Switch
Remote Start/Stop Interlock
An addional contact is provided to allow the remote starng or stopping of the chiller. To use this
feature install a switch or dry contact interlock connected in series between terminals 4 and 23.
Refer to the electrical schemac supplied in the control enclosure. Once the wiring is complete the
controller will need to be recongured in the supervisor sengs.
2-5 Optional Features
Opons marked with “*” indicate opons that can be factory installed or retroed in the eld.
Automac Water Make-Up*. Not available on chillers less reservoir tank. This opon includes an
electric water solenoid valve, and the necessary internal piping to connect the chiller to a make-up
water source. The controller uses the standard tank level pressure transducer to determine when to
ll the tank. See Appendix for typical piping diagrams.
Customer piping must provide backow protecon and venng of tank to atmosphere
to prevent over-pressurizaon of the reservoir tank (not needed for open tank). See
Secon 7-7 for ow schemacs.
Process Water Side-stream Filter*. Not available on chillers less pump and reservoir tank. This
opon includes a 50 micron lter, ow indicator, ball valve for throling water ow, and the
necessary piping to provide constant ltering of the process water at about one gallon per minute (1
gpm/3.8lpm).
General Fault Indicator Audible/Visual Alarm*. This opon includes a 100 dB audible alarm horn/
visual alarm strobe and silence buon with provisions for customer wiring indicaon interlock. The
alarm signals anyme that a fault is recognized during the operaon of the chiller.
Communicaons Opons*. This opon provides the capability for the unit’s controller to
communicate with an external device using a variety of serial communicaon protocols. Currently
the unit can communicate over RS-485 Modbus RTU, BACNet, LONWorks, Ethernet Modbus.
High Pressure Fans. Provides either 0.3” WC (75 Pa) or 1.0”WC (250 Pa) of external stac pressure
on fan discharge. High-pressure fans are necessary and must be included in chiller installaons
where exing air exhausts through ductwork.
The 0.3” WC (75 Pa) stac fan can be retroed without sheet metal modicaon, but will require
changing out fan housing, fan blades, fan motors and electrical components.