We are committed to a continuing program of product improvement.
Specifications, appearance, and dimensions described in this manual are subject to change without notice.
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 mounting screws, etc.
In the Event of Shipping Damage
According to the contract terms and conditions of the Carrier, the responsibility of the
Shipper ends at the time and place of shipment.
Notify the transportation company’s local agent if you discover damage
Hold the damaged goods and packing material for the examining agent’s inspection. Do not
return any goods before the transportation company’s inspection and authorization.
File a claim with the transportation company. Substantiate the claim by referring to the
agent’s report. A certified copy of our invoice is available upon request. The original Bill of
Lading is attached to our original invoice. If the shipment was prepaid, write us for a
receipted transportation bill.
Advise customer service regarding your wish for assistance and to obtain an RMA (return
material authorization) number.
If the Shipment is Not Complete
Check the packing list as back-ordered items are noted on the packing list. In addition to the
equipment itself, you should have:
Bill of lading
Packing list
Operating and Installation packet
Electrical schematic and panel layout drawings
Component instruction manuals (if applicable)
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, contact the parts and service department
immediately at (262) 641-8610. Have the order number and item number available.
Hold the items until you receive shipping instructions.
Returns
Do not return any damaged or incorrect items until you receive shipping instructions from the
shipping department.
Use this manual as a guide and reference for installing, operating, and maintaining your
equipment. 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 optional
features. Additional sections within the manual provide instructions for installation, preoperational procedures, operation, preventive maintenance, and corrective maintenance.
The Installation chapter includes required data for receiving, unpacking, inspecting, and setup
of the equipment. 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 equipment.
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 equipment 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 equipment 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, and parts lists. 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.
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 indicates an imminently hazardous situation which, if not avoided, will result in
death or serious injury.
WARNING indicates a potentially hazardous situation or practice which, if not avoided,
could result in death or serious injury.
CAUTION indicates a potentially hazardous situation or practice which, if not avoided,
may result in minor or moderate injury or in property damage.
GP Series Portable Chillers Chapter 1: Safety 5 of 90
1-2 Warnings and Precautions
Our equipment is designed to provide safe and reliable operation when installed and operated
within design specifications, following national and local safety codes.
To avoid possible personal injury or equipment damage when installing, operating, or
maintaining this equipment, use good judgment and follow these safe practices:
Follow all SAFETY CODES.
Wear SAFETY GLASSES and WORK GLOVES.
Disconnect and/or lock out power before servicing or maintaining the equipment.
Use care when LOADING, UNLOADING, RIGGING, or MOVING this
equipment.
Operate this equipment within design specifications.
OPEN, TAG, and LOCK ALL DISCONNECTS before working on equipment.
You should remove the fuses and carry them with you.
Make sure the equipment and components are properly GROUNDED before you
switch on power.
When welding or brazing in or around this equipment, make sure
VENTILATION is ADEQUATE. PROTECT adjacent materials from flame or
sparks by shielding with sheet metal. An approved FIRE EXTINGUISHER
should be close at hand and ready for use if needed.
Refrigeration systems can develop refrigerant pressures in excess of 500 psi
(3,447.5 kPa/ 34.47 bars). DO NOT CUT INTO THE REFRIGERATION SYSTEM. This must be performed by a qualified service technician only.
Do not restore power until you remove all tools, test equipment, etc., and the
equipment and related components are fully reassembled.
Only PROPERLY TRAINED personnel familiar with the information in this
manual should work on this equipment.
We have long recognized the importance of safety and have designed and manufactured our
equipment with operator safety as a prime consideration. We expect you, as a user, to abide
by the foregoing recommendations in order to make operator safety a reality.
1-3 Responsibility
These machines are constructed for maximum operator safety when used under standard
operating conditions and when recommended instructions are followed in the maintenance
and operation of the machine.
All personnel engaged in the use of the machine should become familiar with its operation as
described in this manual.
Proper operation of the machine promotes safety for the operator and all workers in its
vicinity.
Each individual must take responsibility for observing the prescribed safety rules as outlined.
All warning and danger signs must be observed and obeyed. All actual or potential danger
areas must be reported to your immediate supervisor.
GP Series Portable Chillers Chapter 1: Safety 6 of 90
Chapter 2: Functional Description
2-1 Models Covered in This Manual
This manual provides operation, installation, and maintenance instructions 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 contacting 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 refrigeration). All are self-contained, fully portable and
shipped ready to use. (Remote air-cooled chillers require field installation by qualified
technicians.) In the standard configuration the chiller basically consists of a pump, tank,
compressor, condenser, evaporator, and a control platform. All of these components, plus the
other integral components to maintain the leaving fluid temperature, are described throughout
this Chapter as well as Chapters 3 and 4.
Standard range of operation is 20ºF to 80ºF (-7ºC to 27ºC) for applications using a
water/glycol mix and 45ºF to 80ºF (7º to 27ºC) for water only applications.
Typical Applications
This series of portable chillers can be used in any application that needs a constant source of
cool process water. Typical applications include, but are not limited to, the following:
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 Chapter 2: Functional Description 7 of 90
Process Fluid Temperature – The standard range for the leaving fluid temperature for this
series of packaged chillers is 20°F to 80°F (-6.7°C to 26.7°C). When the process requires
fluid temperatures below 45°F (27.2°C) it is imperative that the process fluid 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 applications.
WARNING! - ACS Group does not warrant the freeze up of the evaporator
under any circumstances.
Chilled Water Circuit
Cooling water “To Process” and “From Process”
connections 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 flows 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 flow through the unit during the intermittent
fluctuating flow conditions. It is not intended to provide
continuous full bypass flow.
This minimal flow allows the flow switch to make when
the process flow is stopped. If the flow switch is not made the controller shuts down the
compressor to prevent freezing up the evaporator.
GP Series Portable Chillers Chapter 2: Functional Description 8 of 90
Refrigeration Circuit
Air-, water-, and remote air-cooled refrigerant condensing differ 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
flows 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 flowing in the liquid line passes through
a shut-off valve into a filter/dryer that removes
moisture and other contaminants. After the
filter/dryer the refrigerant passes through a solenoid
valve to prevent liquid migration when the
compressor is off. A refrigerant sight glass is
provided to view the flow 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 off) and cool (remove the heat from)
the fluid inside of the evaporator.
From the evaporator the refrigerant gas flows
through the suction line back into the compressor.
A modulating electronic hot gas bypass valve is used to control cooling capacity during
intermittent or partial load conditions. This feature contributes substantially to chiller
longevity by eliminating excessive cycling of the compressor and providing close
temperature control.
System Control
Putting this all together, the controller maintains the desired leaving fluid temperature using
multiple 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 operation of the controller) it verifies there is sufficient fluid level in the tank (if
present). If there is not enough fluid in the tank the controller will warn the user, or fill the
tank with water from a connected source if equipped with the optional automatic water
makeup valve. See Chapter 3 for more information regarding the initial setup and startup of
the unit.
Once the tank level is satisfied and the start button is pressed, the process pump turns on and
provides flow to the process. The controller verifies the flow through the electronic flow
switch. If the flow is not established within 10 seconds the controller will alarm and disable
the refrigeration circuit. Upon flow verification the controller uses the leaving fluid
temperature and the setpoint temperature to determine the operation of the compressor(s).
When the leaving fluid temperature is greater than the setpoint plus the “compressor on
GP Series Portable Chillers Chapter 2: Functional Description 9 of 90
differential” 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 fluid temperature remains above the setpoint plus
the “compressor on differential” 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 fluid setpoint via a PID algorithm. After the compressor starts,
the hot gas valve is allowed to modulate. The compressor will shut off if the leaving fluid
temperature drops below the “compressor off differential” and the hot gas valve is at 100%
for the “compressor off delay” time. The hot gas will reset to 0% when the compressor is off.
There is a “compressor anticyle” timer that will delay the time between compressor starts to
prevent short cycling of the compressor. This is a start to start timer set at 5 minutes. For
example, if the compressor has been running for 5 minutes and shuts off, 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 fluid temperature is above the
setpoint plus the “compressor on differential”. There is also an adjustable “lag compressor on
delay” timer. Before starting either compressor, the compressor with the least amount of
runtime hours is considered the lead compressor and the first to start. When both
compressors are running, the compressor with the most hours is considered the lead
compressor and is the first to stop. The lead compressor will shut off if the leaving fluid
temperature drops below the “compressor off differential” and the hot gas valve is at 100%
for the “lead compressor off delay” time. The compressor anti-cycle timers are active with
the two compressor units.
There will be two PID controls running simultaneously for determining the position of the hot
gas valve. One PID output will be based on leaving fluid temperature and the other based on
a minimum saturated suction temperature for freeze protection. The hot gas valve position
will be determined by which output is greater. If it is controlling to the saturated suction
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 suction temperature is calculated from the suction pressure and the type of
refrigerant.
The discharge pressure is controlled using an analog output signal to drive a fan for aircooled units or a water regulating 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 regulating valve is controlled from the analog output to an
adjustable discharge pressure setpoint. The analog output starts at the initial “discharge
pressure start” % for a given time delay (discharge pressure hold). After the time delay, it
will control to the discharge pressure setpoint via the PID control. There is also a setting to
control the discharge pressure to the most efficient value.
GP Series Portable Chillers Chapter 2: Functional Description 10 of 90
Air-Cooled Condenser – Aluminum fin/ tube with washable filters, packaged units only.
Variable speed fan control standard for all remote air cooled condensers and GPAC70
through 210. Optional on GPAC20 through 50.
Water-Cooled Condenser – Tube-in-tube condensers (GPWC20 – GPWC50), Shell-andtube condensers (GPWC70 – GPWC210). All come with electronic cooling water regulating
valves.
Remote Air-Cooled Condenser– Aluminum fin/tube with low ambient control down to
–20ºF (-29ºC) via variable-speed fan(s).
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 option for all sizes.
Internal process water bypass valve for system protection only
Fully insulated refrigeration and process water piping
20 mesh Y strainer on process water piping into the evaporator
Tank level indication via operator interface
Pump pressure indication via operator interface
Electrical Features
Fully accessible NEMA 4/12-style electrical control enclosure
Single-point power and ground connection
Non-fused disconnect switch, lockable
Branch circuit protection
208-230/3/60, 460/3/60, 575/3/60 volt; 400/3/50 volt
Refrigeration Features
HFC-410a refrigerant
Electronic modulating hot gas bypass capacity control
High refrigerant pressure cutout switch (manual reset)
Suction and discharge pressure transducers.
High refrigerant pressure spring actuated relief valve
GP Series Portable Chillers Chapter 2: Functional Description 11 of 90
Multiple refrigeration access ports
Liquid line shut-off ball valves
Filter-dryer
Sight glass
Externally equalized thermal expansion valve
Liquid line solenoid
Compressor crankcase heater
Controller Features
Off-the-shelf microprocessor-based PID controller with To Process, From Process and
Set Point readout
Time delay for proof of water flow/pressure (models w/pump only)
Low refrigerant pressure time delay for low ambient start-up on remote air-cooled and
air-cooled chillers with the variable-speed fan option.
8 line x 22 character display with status, alarm, and service screens
Display has magnetic 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
Caution! Protect the system from freezing with inhibited industrial grade glycol 20ºF
below the leaving water temperature set point. Condensation may form inside
the pump tank and dilute the mixture, therefore the freezing point should be
verified 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 continuously whenever power is applied to the chiller, and
the compressors are off.
Caution! Energize the crankcase heater for at least 24 hours before initial 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 migration to the compressor.
GP Series Portable Chillers Chapter 2: Functional Description 12 of 90
High Pressure Cutout
High pressure cutout
This electro-mechanical cutout device opens the compressor control circuit if the refrigeration
system compressor discharge pressure exceeds 575 psig.
Note: The high-pressure cutout is a manual reset device typically mounted on the
compressor discharge line inside the mechanical cabinet. Call a refrigeration
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 refrigeration piping – one on the suction line before
the compressor and one on the discharge line after the compressor. Within the program there
are four settings that warn and fault based on these two pressure transducers. The low suction
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.
Note: Call a refrigeration service technician to analyze the problem to prevent
recurring low pressure faults.
GP Series Portable Chillers Chapter 2: Functional Description 13 of 90
Flow Switch
The thermal dispersion flow switch cutout device, mounted in the process piping, shuts down
the chiller if it senses that the water/glycol flow rate through the evaporator has dropped
below an acceptable level. The flow switch opens the control circuit and shuts down the
pump and the chiller.
Remote Start/Stop Interlock
An additional contact is provided to allow the remote starting 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 schematic supplied in the control enclosure. Once the wiring
is complete the controller will need to be reconfigured in the supervisor settings.
2-5 Optional Features
Options marked with “*” indicate options that can be factory installed or retrofitted in the
field.
Automatic Water Make-Up*. Not available on chillers less reservoir tank. This option
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 fill the tank. See Appendix for typical piping diagrams.
Caution! Customer piping must provide backflow protection and venting of tank to
atmosphere to prevent over-pressurization of the reservoir tank (not needed for
open tank). See Section 7-7 for flow schematics.
Process Water Side-stream Filter*. Not available on chillers less pump and reservoir tank.
This option includes a 50 micron filter, flow indicator, ball valve for throttling water flow,
and the necessary piping to provide constant filtering of the process water at about one gallon
per minute (1 gpm/3.8lpm).
General Fault Indicator Audible/Visual Alarm*. This option includes a 100 dB audible
alarm horn/ visual alarm strobe and silence button with provisions for customer wiring
indication interlock. The alarm signals anytime that a fault is recognized during the operation
of the chiller.
Communications Options*. This option provides the capability for the unit’s controller to
communicate with an external device using a variety of serial communication 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 static
pressure on fan discharge. High-pressure fans are necessary and must be included in chiller
installations where exiting air exhausts through ductwork.
The 0.3” WC (75 Pa) static fan can be retrofitted without sheet metal modification, but will
require changing out fan housing, fan blades, fan motors and electrical components.
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 option will also reduce fan noise in lower ambient temperatures and low loads.
GP Series Portable Chillers Chapter 2: Functional Description 14 of 90
Stainless Steel Reservoir. Manufactured from 304 stainless steel.
Voltage
Construction
HP (kW)
Full Load Amps
2 (1.5)
4.0
3 (2.2)
4.2
5 (3.7)
8.2
7.5 (5.6)
10.3
10 (7.5)
12.0
15 (11)
20.0
Mounting Features.
Mounting rails with feet – GP20-GP105 indoor units. Standard on GP140-GP210 and all
outdoor packaged units.
Optional Operating Voltages. 208-230/3/60, 460/3/60, 575/3/60, and 400/3/50 volt
available
UL/cUL Labeled Electrical Subpanel. This option provides for the subpanel to be listed
with Underwriters Laboratory, with UL-related benefits and features. Sub-panels marked by
the UL/cUL sticker are accepted within Canada.
Optional Pumps. Pump options are available for greater pressure and flow rates. A
recirculation pump is required whenever process water flow is less than 1.2 gpm per ton or
greater than 4.8 gpm per ton. See Figure 1 below for optional pump amperages.
Figure 1: Optional Pump Amperages
460/3/60 SS 1 (0.8) 1.7
1.5 (1.1) 2.3
GP Series Portable Chillers Chapter 2: Functional Description 15 of 90
30 (22) 32.0
Chapter 3: Installation
Important!
3-1 Uncrating
All models are shipped mounted on a skid, enclosed in a plastic wrapper, and open-crated on
all four sides and top.
1. Pry the crating away from the skid.
2. Use a pry bar to remove the blocks securing the unit to the skid.
3. Lift unit from sides, inserting forklift under the base. The forks must be equidistant
from the centerline of the unit and the unit must be balanced on the forks. Lift slowly
and only high enough to clear the skid. Use a pry bar if necessary to carefully remove
the skid from the unit.
4. Lower slowly. The unit should land on its casters or rails and can then be moved into
position.
5. Retain the crating material for reshipping the chiller in case hidden shipping damage
is found.
3-2 Electrical Connections
Supply electricity of the voltage, phase, and cycle listed on the serial tag. Total running amps
are also found in the specification tables on pages in the Appendix.
Bring properly sized power leads and ground from a fused disconnect (installed by your
electrician) to the unit. Use dual-element fuses in the disconnect switch, sized according to
the National Electrical Code recommendations. Make sure all electrical connections are tight.
Refer to your local electrical requirements for proper feeder conductor and
supply disconnecting sizing. For instance, in the United States refer to
National Electric Code (NEC) Article 430-24 through 430-26, Table
Note: For all chillers manufactured with Variable Frequency Drives the
voltage may vary up to 10% from the converter nominal voltage.
However, the phase-to-phase input voltage imbalance must not
exceed 3%. If the input voltage does have an imbalance from phase
to phase greater than 3% then a line reactor must be installed to
prevent faults within the VFD.
For remote condenser units, the maximum recommended motor
cable length between the VFD and the motor without output chokes
is 30 m (100 ft). With output chokes the motor cable length may be
extended to 65 m (195 ft).
310.15(B)(2)(a)
GP Series Portable Chillers Chapter 3: Installation 16 of 90
3-3 Process Water Connections
All of our portable chillers have two chilled water connections. The chilled water supply,
labeled “To Process” is the outlet for the chilled water leading to the process being cooled.
The chilled water return, labeled “From Process” is the inlet leading from the process back
into the chiller to be cooled and re-circulated.
Figure 2: Typical GP20-50 Air Cooled Process Piping Connections
All external chilled water connections should be run full size to the process. Flow and
pressure information is available in the Appendix. The largest possible openings and
passages should be provided for the flow of chilled water through platens, dies, molds, or
other pieces of equipment. Flow control valves are not supplied, but should be added to the
system to adjust flow and pressure to the process and to isolate the chiller from the process if
necessary.
Note: Be sure to reduce external pressure drop as much as possible by generously
sizing piping and tooling water passageways.
3-4 Bypass Valve Considerations
Our portable chillers have an internal manual bypass valve. If the flow is stopped to the
process while the chiller is running, the factory-set bypass valve allows a small amount of
water to flow through the chiller. This action allows the chiller to keep functioning while the
flow is stopped to process. The bypass valve is not intended to provide continuous full
bypass flow.
Caution! Do not attempt to adjust or otherwise tamper with the internal bypass. Your
warranty will be voided.
GP Series Portable Chillers Chapter 3: Installation 17 of 90
3-5 Galvanic Corrosion Considerations
The materials used in the water circuit piping of these chillers are non-ferrous and react
electro-chemically with ferrous metallic materials. Some water has dissolved minerals that
greatly accelerate the reaction between dissimilar metals.
PVC or non-ferrous piping is recommended to reduce galvanic action. If iron piping must be
used, use dielectric unions at the chiller, and water treatment is required.
Note:The use of galvanized piping is discouraged because the rough inside surface
promotes debris to stick and eventually block the flow of the process fluid..
3-6 Water Treatment Considerations
Water treatment is an integral part of the system. In some locations, water may cause large
deposits of scale, erosion, algae, and/or corrosion.
Note:The use of poor quality water may result in inefficient operation, heat
exchanger damage, and pump seal damage. Consult a qualified water
treatment specialist to determine what type of treatment is needed.
3-7 Condenser Considerations
Water-Cooled Chiller Condensers
Water-cooled portable chillers can use city water or tower water as a cooling medium. Make
sure that all external piping and connections supplying and discharging water to and from the
condenser are full size.
You will make two connections to the water-cooled condenser:
Condenser Water In. The condenser water supply is labeled “Condenser Water In.” It is the
inlet for city or tower water. For the GPWC20-50, this connection is located near the bottom
of the chiller. For all other sizes this connection is located near the top of the chiller.
Make sure that water is supplied at a maximum temperature of 85ºF (29ºC) and a minimum
pressure of 25 psi.
Caution! The electronic water-regulating valves pressure setpoint is set at the factory.
Only a qualified refrigeration technician should adjust the pressure setting.
Please contact our service group at 800-423-3183 to schedule an appointment.
Normal HFC-410a refrigerant condensing pressure is 342 psi (2,360 kPa), with 85ºF (27ºC)
water at 25 psi entering condenser water pressure
Condenser Water Out. Condenser water return is labeled “Condenser Water Out.” It is the
outlet for water after it has passed through the condenser. For the GPWC20-50, this
connection is located near the bottom of the chiller. For all other sizes this connection is
located near the top of the chiller.
It is connected to the tower water return line or to a sewer or other approved discharge
receiver. A water-regulating valve is a standard feature in the condenser water out line.
GP Series Portable Chillers Chapter 3: Installation 18 of 90
Figure 3: Typical GP20-50 Water Cooled Condenser Connections
Air-Cooled Chiller Condensers
Air-cooled chillers use the surrounding air to cool the condenser. Install the chiller in an area
where there is free passage of air for condensing and provisions for removal of heated air
from the area. Do not locate air-cooled chillers in locations where steam, hot air, or fume
exhausts can be drawn into the chiller.
Caution! Clean air-cooled condensers and filters frequently. Failure to do so results in
reduced capacity, increased operating costs, and possible failure of the
equipment. Cleaning instructions can be found in the Maintenance chapter of
this manual
Normal maximum refrigerant condensing pressure with 95ºF (35ºC) air entering the
condenser is 420 psi (2896 kPa).
Condensing Air Temperature. Our air-cooled portable chillers are designed to operate at a
minimum condenser entering air temperature of approximately 75ºF (24ºC). Operation of the
equipment at a lower condenser entering air temperature can cause the chiller to malfunction.
For entering air temperatures below 75ºF (24°C), an optional fan motor speed control is
available. We recommend maintaining a minimum 75ºF (24°C) ambient temperature.
Note: For all chillers manufactured with Variable Frequency Drives the
voltage may vary up to 10% from the converter nominal voltage.
However, the phase-to-phase input voltage imbalance must not
exceed 3%. If the input voltage does have an imbalance from phase
to phase greater than 3% then a line reactor must be installed to
prevent faults within the VFD.
For remote condenser units, the maximum recommended motor
cable length between the VFD and the motor without output chokes
is 30 m (100 ft). With output chokes the motor cable length may be
extended to 65 m (195 ft).
GP Series Portable Chillers Chapter 3: Installation 19 of 90
Remote Air-Cooled Chiller Condensers
Remote air-cooled portable chillers are shipped with nitrogen holding charge and a full
charge of oil (excluding the amount needed for field piping). The remote air condenser is
shipped with a dry nitrogen charge. Verify that the holding charge has not been lost prior to
installation. If there is no pressure, leak test the unit and repair before installing the
interconnecting refrigerant piping. Read this entire section before installation.
Note: Piping should be hard/drawn type “L” or type “K” refrigerant grade copper
tubing only. Proper sizing and installation has a significant effect on system
performance, reliability, and safety.
Warning! The copper tubing and fittings used must have a minimum burst
pressure of 1,950 psi.
Interconnecting Refrigerant Piping. The chiller and condenser refrigerant lines are
terminated with a cap and brazed closed. Use a tube cutter to remove caps.
Caution! Do not use a saw to remove the end caps because this will allow copper chips to
contaminate the system.
A certified refrigeration contractor needs only to install the interconnecting refrigerant piping
between the chiller and the outdoor air-cooled condenser. This piping must be properly sized,
type “L” or type “K” refrigerant grade tubing, high temperature brazed. Install a customer
supplied 650 psi approved refrigerant relief valve in the discharge line at the condenser,
following all applicable codes.
Flow dry nitrogen through the system when brazing copper joints to prevent carbon/scale
formation; which causes contamination. Isolate the refrigerant lines from the building,
preventing transfer of line vibration to the structure. Do not secure the lines rigidly.
Leak check and evacuate the system down to 400 microns. A decay of 50 microns after one
hour is acceptable.
Warning! To prevent injury or death due to explosion and/or inhalation of hydrogen-
fluoride gas, purge system thoroughly while brazing refrigerant piping
connections. Use a pressure regulator in the line between the unit and the
high-pressure nitrogen cylinder to avoid over-pressurization and possible
explosion.
System Configuration. The system can be configured in any of the arrangements shown on
page 75 of the Appendix. The configuration and distance between the chiller and the
condenser affects pipe size, refrigerant charge, oil return, and oil charge. Therefore there are
limitations that must be adhered to for reliable and optimal operation.
Leaving water temperature affects discharge line size. Be sure to inform the installing
contractor of the leaving water temperature range in which the chiller will be operating
The total distance between the chiller and condenser must not exceed 200 feet or 300
equivalent pipe feet
Discharge line risers cannot exceed an elevation difference greater than 100 feet
without a 2% efficiency decrease.
Refer to page 75 of the Appendix for the location of traps.
Refrigeration lines must not be crossed, i.e., chiller liquid lines are to be piped to
condenser liquid lines.
GP Series Portable Chillers Chapter 3: Installation 20 of 90
Sizing Refrigerant Lines. To determine field installed liquid and discharge line sizes, first
OD (inches)
Valve
Radius EL
Radius EL
3/4
25
6.5
4.5
1-1/8
29
2.7
1.9
Length (Ft)
Liquid Line Size (OD")
Length (Ft)
Liquid Line Size (OD")
Horizontal
Downflow
1-5 Ft
6-10 Ft
11-15 Ft
Horizontal
Downflow
1-5 Ft
6-10 Ft
11-15 Ft
establish the equivalent length of pipe for each line, valve, and elbow. Chiller capacity and
leaving water temperature range is also required. See Figure 4 on page 21 for lengths of
refrigerant valves and fittings.
Liquid Line Sizing. The liquid line should be sized as small as possible while maintaining
acceptable pressure drop to minimize the refrigerant charge. Liquid line risers must not
exceed 15 feet from the base of the air-cooled condenser. Horizontal runs do not require a
pitch. Insulation is not required unless the line is installed in a high ambient area, i.e., boiler
room or on a roof. Install a liquid line-charging valve to facilitate refrigerant charging. See
Figure 5 on page 21 for sizing information. See Figure 7 on page 25 for charge determination.
Discharge Line Sizing. Discharge line sizing is based on the velocity required for sufficient
oil return back to the compressor. See Figure 4: Equivalent Length in Feet for Valves and
Fittingson page 24 for discharge line sizing.
Note: For horizontal runs, the discharge line should be pitched downward, in the
direction of flow, at a rate of 1/2” for every 10 feet. This will allow oil to flow
towards the condenser.
Figure 4: Equivalent Length in Feet for Valves and Fittings
GP Series Portable Chillers Chapter 3: Installation 24 of 90
Refrigerant Charge Determination. The approximate amount of refrigerant charge required
OD (inches)
LBS of R-410a
LBS of R-410a
1/2
0.6
6.0
3/4
1.5
14.4
1-1/8
3.7
34.1
1-3/8
5.6
52.0
2-1/8
13.7
128.0
by the system varies based on the total length of the refrigerant lines and the size of the
chiller. Referring to Figure 7, determine the amount of charge based on the model of the
chiller and the amount of charge based on discharge and liquid line sizes and lengths. Add
these three numbers together to find the final operating charge. The final operating charge
must be verified by running the system and checking the liquid line sight glass.
Figure 7: Refrigerant Charge Determination
Condenser and Chiller Charge (LBS of R-410a)
Chiller
Model
60 50 40 30 20 10 0 -10 -20
GPRC-20
GPRC-30
GPRC--40
GPRC-50
GPRC-70
GPRC-90
GPRC-105
GPRC-140
GPRC-175
GPRC-210
9 9 10 11 12 13 13 13 14
10 10 12 14 15 16 16 17 17
13 13 15 17 19 20 21 21 22
18 19 22 25 27 29 30 31 32
25 25 25 26 31 34 36 38 40
30 30 30 32 37 41 44 47 49
51 51 51 52 52 58 63 67 71
51 51 51 51 51 51 55 55 65
70 70 70 70 70 70 76 76 88
80 80 80 80 80 80 80 88 94
Line Size
Discharge Line
Minimum Design Ambient - °F
Liquid Line
3/8 0.3 3.2
5/8 1.0 9.6
7/8 2.1 20.0
1-5/8 7.9 73.6
2-5/8 21.2 197.4
Note: The amounts listed above are based on 100 feet of pipe. Actual amounts will be in
direct proportion to the actual length of the piping.
Oil Charge Determination. The remote air-cooled portable chillers are factory charged with
the amount of oil required without field-installed piping. Additional oil required is dependent
on the amount of additional refrigerant added.
Calculate the amount of additional oil required by using the following formula:
Pints of oil (Copeland Ultra 22cc) = lbs of R-410a added for field installed piping / 100.
GP Series Portable Chillers Chapter 3: Installation 25 of 90
Figure 8: Remote Condenser Configurations
GP Series Portable Chillers Chapter 3: Installation 26 of 90
Figure 9: Double Riser Detail
3-8 Checking Motor Direction
All of our portable chillers have their motor rotations properly phased at the factory. If
compressors, pumps, or fans are running in reverse rotation, disconnect and lock out the
power source and reverse any two power leads into the chiller disconnect switch.
Caution! Do not switch leads at the motors, motor starters, or contactors.
Three-Phase Compressors
Scroll compressors are directionally-dependent and compress in one rotational direction.
Reversing rotation direction results in an elevated sound level and a substantially-reduced
current draw.
Caution! Do not allow the compressor to run backwards for any length of time. Doing
so will result in compressor damage..
Water Pumps
Correct pump rotation is indicated by a positive pressure of 20 to 40 psi shown on the home
screen of the display. Pump rotation should be clockwise when viewed from the motor end.
For chillers with optional pumps, check the appropriate pump curve in the Appendix.
Caution! Do not run pump dry. Doing so will result in seal damage.
Condenser Fan
Air should be drawn through the condenser and discharged vertically from the chiller.
GP Series Portable Chillers Chapter 3: Installation 27 of 90
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