AIRTAK C-25 through C-8000 Manual

107 W. Main Street
Worthington, PA 16262
Phone: [phone] Fax: [phone]
http://www.airtak.com
INSTALLATION, OPERATION AND MAINTENANCE
Instructions for
Refrigerated Water Chillers
Models C-25 through C-8000

2
CONTENTS
A. INTRODUCTION
B. RECEIVING
C. LOCATION
D. FOUNDATION
E. PIPING
F. ELECTRICAL
G. CHILLED FLUID CIRCUIT -1. Fluid to Refrigerant Heat Exchanger.
H. REFRIGERANT CIRCUIT
1. Refrigerant Compressor
2. Air Cooled Condenser and Condenser Fan Cycling
control (Low Ambient)
3. Fluid to Refrigerant Heat Exchanger (Evaporator)
4. Expansion Valves
5. Hot Gas Bypass Valve (C-100 and Larger)
6. Low Pressure Switch
7. High Pressure Switch
8. Crankcase Heater
9. Automatic Water Regulating Valve
10. Oil Sightglass
11. Low Oil Pressure Switch
12. Refrigerant Liquid Line Filter Dryer
13. Water Pressure Switch
14. Desuperheating Valve (C-750 and Larger)
15. High Temperature Control
16. Start Timer
17. Pump Down System
18. Freeze Control
I. START-UP
J. DESIGN CONDITIONS
K. SHUTDOWN
L. MAINTENANCE-1. Refrigeration Condenser
2. Condenser Fans
M. TROUBLESHOOTING GUIDE 9/99

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A. INTRODUCTION
AIR/TAK Refrigerated Fluid Chillers are of the high-efficiency type, designed to effectively remove heat
from process cooling fluids by means of a refrigeration process. The process fluid temperature is
reduced to the temperature required by your machinery.
AIR/TAK chillers are completely automatic in all respects. As with all AIR/TAK products, minimal
maintenance is required. It is our recommendation that this manual be followed for any maintenance that
might be required. Any, and all, service should be performed by a qualified refrigeration technician, who
is trained in the service of refrigerated water chillers.
B. RECEIVING
Upon receiving your chiller:
1. Inspect the shipping carton for any apparent damage.
2. After removing the crate, inspect the unit for any hidden damage.
3. Report any damage immediately to the carrier and notify your supplier.
C. LOCATION
Selecting the proper location:
Air-cooled chillers must have cool room air made available to prevent a heat build-up in the area where
the chiller is installed. An exhaust system is recommended to avoid recirculation of hot air from the
condenser.
Room temperature at the selected location should not exceed 100°F (35°C), 60 HZ: or 77°F (25°C), 50
HZ, and should not be lower than 50°F (10°C). High room temperatures can effect the efficiency of the
chiller. Every 10°F increase in ambient temperature above 95°F (35°C) will result in a 6% decrease in air
cooled chiller performance, resulting in higher outlet temperatures and increased operating costs.
To assure an unrestricted flow of cool air through the refrigeration condenser, a minimum distance from
the cabinet to the nearest wall of twenty-four inches must be maintained.
All outside installations must have weather protection. Minimum protection should include a shed roof.
Air-cooled units must be protected against the wind.
Outside ambient temperature must not exceed 100°F (38°C) nor be lower than 50°F (10°C) where a
standard unit is to be located. If ambients below 50°F (10°C) are anticipated, the chiller should be
equipped with an optional ultra-low ambient package.

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D. FOUNDATION
All chillers are completely free-standing units. Any reasonably level floor that has sufficient strength will
serve as a foundation.
E. PIPING
When piping the main fluid lines to the chiller, the use of flexible connections are recommended to avoid
piping stress and vibration.
All water-cooled chillers are factory piped for cooling tower water. All water-cooled chillers are supplied
with a factory mounted automatic water regulating valve which is designed to maintain the proper
working refrigerant head pressure under all chiller load conditions. No adjustment will be necessary.
(Full water pressure and flow should be supplied to the water line inlet). Refer to Section L for water
cooled water requirements.
F. ELECTRICAL
Chiller nameplate must be checked to verify voltage, phase and cycle. Three phase hermetic
refrigeration compressors are designed to operate in either direction of rotation. To change fan rotation,
switch any two power leads in the terminal box located at the rear of the chiller.
FOR MODELS C-750 AND LARGER, FAN ROTATION MUST BE CHECKED TO ASSURE PROPER
AIR FLOW. AIR MUST ENTER IN THROUGH THE FINNED CONDENSER COIL AND EXIT OVER
THE fAN MOTOR.
The chiller is completely wired at the factory. A terminal box or plug at the rear of the chiller is provided
for the main power connection. WATER PUMP(S) MUST BE CHECKED FOR PROPER ROTATION.
Power connections can be made through the pre-drilled hole on the bottom of the terminal box. Connect
the power leads to the terminal block which is conveniently located within the box. Always be sure
adequate power is available to maintain efficient operation of your chiller.
Models C-100 and larger, are equipped with crankcase heaters as standard. The crankcase heaters are
pre-wired at the factory to be energized at all times. (See Start-Up). Your chiller is equipped with a
pumpdown system. The chiller may begin to run immediately after being energized for a short period of
time which is normal.
A properly sized fused main disconnect switch (supplied by the installer) must be located near the chiller.
Check the wiring diagram supplied with the chiller for the recommended fuse size. The use of fusetron
time-delay fuses will permit smaller fuse sizes and, in some instances, a smaller fused disconnect
switch may be used.
The chiller wiring must be independent of the chilled water heat load so as not to cycle along with the
machinery.

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G. CHILLED WATER CIRCUIT
1. Chilled Water-to-Refrigerant Heat Exchanger (Evaporator):
This exchanger is of the brazed plate stainless steel design. The evaporator is engineered with
maximum efficiency in mind.
2. Water pump: The water pump must be checked for proper direction of operation. Set GPM by amps
compared to pump curve. The discharge ball valve must also be adjusted to regulate the proper
gallon per minute flow to the evaporator as stated on the data label found on the back panel of the
chiller. Failure to do so may result in a lack of water pressure to the equipment being cooled or a
lack of water temperature drop through the evaporator. THE PUMP SHOULD NEVER BE RUN
WITHOUT FLUID TO IT.
3. Air vents: Air vents are required at high points in the system to allow the bleeding of air while filling
the system. These vents are to be supplied and installed by the contractor. A water fill port must be
added to the suction line by the contractor. To fill the system, open all air vents and begin filling with
fluid. When a steady stream of fluid comes from the vents with no air, close the vents. To fill the
expansion tank to the proper level, loosen the small nut at the bottom of the airtrol and allow air to
escape until fluid comes out. Tighten the nut. Circulate the fluid by turning on the pump. Repeat
bleeding of air vents until all air has been removed.
4. Water Tank: On an open system the plastic water tank provided allows for easy filling of the chilled
water circuit. Fill the tank by removing the cap at the top of the chiller. Turn the chiller on activating
the pump to fill piping. Being aware of the water level in the tank, add if it should run low. You
should maintain half capacity in the tank to guarantee a full column of liquid to the pump suction.
H. REFRIGERANT CIRCUIT
1. Refrigerant Compressor:
The refrigerant compressor used is an industrial type, full hermetic or semi-hermetic. These
Compressors can be either single phase or three phase, depending on the application. The
compressors used are designed for high temperature applications which allows an evaporation
temperature range of 20°F (-7°C) to 50°F(10°C.).
Each compressor motor is fully protected by either an internal or external overload which are of the
automatic reset type. All compressors used are suction gas-cooled and have a wide working range.
The connected electrical load can vary with the compressor load, ambient temperature or cooling water
temperature.
2. Air Cooled Condenser and Condenser Fan Cycling Control (Low Ambient):
All air cooled condensers used in the AIR/TAK chillers are industrial plate fin type coils, designed for
maximum ambient conditions. Each condenser has a sub-cooling system which permits the condensed
refrigerant to be sub-cooled below the normal condensing temperature to within 10°F of the ambient
temperature. The condensers are forced convection types and fan motor(s) are controlled by pressure
switch(s) (low ambient control). This pressure switch is activated by the condenser head pressure. This
pressure will vary with the ambient temperature and evaporator load. As the pressure increases to a
factory set cut-in pressure, the fan switch is activated and the fan motor starts. The fan removes the
heat within the condenser and lowers head pressure to the factory set cut-out point. With the fan switch
controlling the upper and lower pressure limits, the chiller can operate through a wide range of ambient
and load conditions. When the ambient is high and the chiller is operating at full load, the condenser
pressure and temperature will stabilize and the fan(s) will run continuously.

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3. Evaporator: Water-to-Refrigerant Heat Exchanger:
The evaporator is constructed of high quality copper tubing. Cold liquid refrigerant is efficiently fed by a
venturi type distributor to each circuit. The circuiting within the evaporator is designed to insure
adequate refrigerant velocity to eliminate the problem of oil return to the crankcase.
4. Expansion Valves:
There are two types of expansion valves used.
a) The first type is the automatic type which is used on all AIR/TAK chillers up to, and including, the
Model C-75. The Automatic Expansion Valve (AEV) is a pressure sensitive valve which
responds to change in evaporator pressure. As the evaporator pressure begins to change in
response to load changes, the automatic valve senses this and adjusts the flow of refrigerant to
maintain a constant pressure within the evaporator.
b) The second type is the Thermostatic Expansion Valve (TXV) used on Model C-100 and larger.
This valve is controlled primarily by temperature. The temperature that is sensed by the (TXV)
thermal bulb is the superheat temperature of the refrigerant at the outlet of the evaporator. This
is the temperature increase of the refrigerant above the saturation temperature corresponding to
the existing evaporator pressures.
5. Hot Gas Bypass Valve C-100 and Larger:
The hot gas bypass valve or capacity regulator permits medium to larger type refrigerated chillers to
operate through the range from zero load to 100% load while maintaining evaporator and suction line
pressure and temperature.
6. Low Pressure Switch:
The low pressure switch is a safety device that protects the refrigeration compressor from low suction
pressure resulting from a loss of refrigerant charge.
7. High Pressure Switch:
The high pressure switch is a safety device that limits the discharge pressure from the refrigerant
compressor. If the discharge pressure exceeds the factory set point, the high pressure switch opens the
electrical circuit to the compressor and the system is shut down.
High discharge pressures may result from conditions such as: plugged or dirty condensers, high ambient
temperature, high fluid inlet temperatures, high fluid flow rates, non-condensables (air or water inside the
refrigeration system) or fan motor failures.
8. Crankcase Heater:
The crankcase heater is a low wattage heater that is connected to or immersed in the refrigerant
compressor crankcase. The wattage of this heater is normally 50 to 65 watts. This heater is not
controlled by the operational switch of the chiller, but is factory wired directly to the incoming power. The
purpose of the crankcase heater is to prevent liquid refrigerant migration back to the crankcase while the
compressor is not in operation. This migration of the liquid refrigerant occurs when the compressor
crankcase is at a lower vapor pressure than the evaporator and other system components. The
crankcase heater must raise the temperature of the crankcase and oil to a temperature higher than the
evaporator and all of the interconnecting piping. To accomplish this, the crankcase heater must be
energized twenty-four hours before the chiller is started. This is accomplished by turning the chiller
operational switch to "OFF" and switching on the main power. The chiller is then allowed to warm up for
twenty-four hours after which time the operational switch may be turned to the "ON" position.

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9. Automatic Water Regulating Valve:
This control is found only in chillers equipped with water cooled condensers. The purpose of the valve is
to control the flow of water through the condenser at a rate that is factory set to maintain a constant
condensing pressure.
10. Oil Sightglass:
The oil sightglass is found on the side of the crankcase on accessible semi-hermetic compressors to
provide a visual means of checking the oil level. The oil must be checked only while the compressor is in
operation. During compressor operation the oil sight glass should be approximately 1/2 full.
11. Low Oil Pressure Switch:
This switch is found on semi-hermetic compressors. The oil pressure switch is a pressure differential
switch which senses the pressure difference between the compressor crankcase pressure and the outlet
pressure of the oil pump. The oil pressure must bemaintained above the crankcase pressure to insure
proper lubrication (minimum pressure of 9 psi).
If an adequate oil pressure over compressor crankcase pressure is not maintained, the low oil pressure
switch will open and shutdown the refrigerant compressor. This switch is a manual reset switch. Before
resetting, the unit must be thoroughly checked to determine the cause of the failure. A built in time delay
of 120 seconds is provided to permit the refrigeration compressor to start and establish a satisfactory oil
pressure.
12. Refrigerant Liquid Line Filter-Dryer:
A liquid line filter-dryer is used on all AIR/TAK refrigerated chillers. The purpose of the filter-dryer is to
eliminate the possibility of moisture, or other foreign particles, from moving throughout the system.
These particles, such as carbon, can cause early compressor failure. The filter-dryer also has a high
quality desiccant which is capable of removing moisture to a very low point and can also remove a
reasonable quantity of acid.
13. Water Pressure Switch:
This control is used only on chillers equipped with water cooled condensers. The purpose of this
switch is to assure that adequate water pressure is available to the refrigerant condenser.
14. Desuperheating Valve:
This valve is used on larger capacity chillers. Due to the larger refrigerant charges associated with
these models, the addition of the desuperheating valve is necessary. The valve's purpose is to
provide liquid refrigerant to desuperheat hot discharge gas used to establish suction gas pressure.
15. High Temperature Control:
This control is used to protect the compressor from excessive return gas temperature. During the
start-up phase, the high temperature light may be lit until the refrigeration system reaches its normal
running temperatures and pressures. (See Start-up; Section I).
During normal operation on Models C-25 through C-1000 this control will activate the high temperature
light when return gas temperatures become excessive. Immediate action is required by the customer to
turn off the chiller. On models C-1200 and above, this control will activate the high temperature light and
will also open the electrical circuit on the compressor and shutdown the chiller. The chiller will not restart
without the customer turning the selector switch to "OFF" and then back to "ON". Customer evaluation
should be undertaken to determine the cause of the high temperature condition.
After start-up, the high temperature light condition may result from: plugged or dirty condensers, high

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ambients, high inlet fluid temperatures or high fluid flow rates.
16. Start Timer:
Standard on C-1200 and larger chillers. This timing device is used in conjunction with the High
Temperature Control in item 16. During start-up, this device will temporarily energize the compressors
electrical circuit. The start timer is factory set to allow adequate time for the refrigeration system to reach
normal suction gas temperatures. If normal suction gas temperatures do not occur within the factory set
time, the compressor will shut down. (See item 16 above.)
17. Pump Down System:
Standard on all chillers above C-150, liquid line and hot gas line solenoid valves are wired to open
when the power on switch is turned on, and to close when the switch is off. When in the off position, the
chiller will pump most of the refrigerant charge into the receiver until the low pressure switch de-
energizes the compressor.
18. Freeze Control:
Standard on all chillers. When the water temperature leaving the evaporator nears freezing, this
switch de-energizes the compressor while allowing the water pump ( if provided ) to continue to run.
I. START-UP
After the installation of your chiller at a suitable location, the following checks should be made:
a) The R-22 refrigerant analyzer gauge should be indicating the chiller shut down pressure of 125-
175 PSIG (70-110 PSIG for 134A). If analyzer pressure is above or below normal shut down
pressure, do not start the chiller. Pressures may vary with ambient temperature.
b) The operational switch must be in the "OFF" position.
c) The main electrical disconnect is energized.
d) The amber power on light is "ON".
e) (Water cooled units only). Open water supply valve.
Units that DO NOT require a crankcase heater (Models C-25 through C-75 can be started immediately
after step E (above) by turning the on off switch on. The red High Temperature Light may remain on for a
short time after the unit is started and the R-22 Refrigerant Analyzer Pressure will drop to its normal
range to indicate 58-76 PSIG (28 –35 PSIG for 134A). When the red High Temperature Light goes out,
the chiller is ready to assume full load operation.
MODELS C-100 AND LARGER ARE EQUIPPED WITH CRANKCASE HEATERS AS STANDARD. THE
CRANKCASE HEATERS MUST BE ENERGIZED TWENTY-FOUR HOURS BEFORE INITIAL START-
UP OR AFTER ANY PROLONGED SHUT DOWN. After the 24hour period, the chiller may be started.
The Refrigerant Analyzer pressure will drop and bring itself to the normal running pressure, 58-76 PSIG
(28 –35 PSIG for 134A). When the red High Temperature light goes out, the chiller is ready to assume
full load operation.
Chillers having dual condenser fans will have one (1) fan which may start when the operational switch is
turned on. The cycling of the fan(s) is controlled by the low ambient control which is factory preset to
maintain the proper head pressure within the refrigerant system.

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J. DESIGN CONDITIONS
Each chiller is shipped complete and ready for installation. Every chiller is tested and preset at the
factory for optimum service at the design conditions. The following are the standard design conditions
for a refrigerated chiller operating at 60 HZ:
K. SHUT-DOWN
All chillers may be shut down by simply turning the operational switch to "OFF." Models C-100, and
larger, require the main power disconnect to remain on unless service or maintenance work is to be
performed. Models C-200-Aand larger have one fan motor wired to run to lower head pressures after
shut-down.
L. MAINTENANCE
A properly installed AIR/TAK refrigerated chiller requires very little in the way of maintenance to provide
years of trouble-free service. A very simple routine maintenance program is all that is required. This
program will consist of two check points:
1. Refrigeration Condenser:
a) Inspect the refrigeration condenser for lint and dirt.
b) The refrigeration condenser should be checked for lint or dirt monthly in a clean
environment and more often in a dirty environment. If the condenser is found to be
dirty, it must be cleaned with low pressure dry air.
c) Check refrigerant lines for oily connections and vibration in lines. Check wiring for loose
and broken wire ties. (See Troubleshooting Guide).
2. Condenser Fans:
a) Inspect condenser fans; i.e., bent or broken blades, and for free rotation.
b) Check condenser fan(s), brackets and on motor shaft for tightness.
3. Gauges:
a) Check gaugesfor proper readings.
4. Circulating Pump:
a) Check for leaks.
b) Grease motor if fitting is supplied.
95
°°
F(35
°°
C)Ambient Temperature
(Room Temperature)

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M. TROUBLESHOOTING GUIDE
SYMPTOM PROBABLE CAUSE REMDY
Chiller not running. (Power
on light off, high temperature
light off, analyzer gauge
normal.)
a. Disconnect open.
b. Fuse blown.
c. Wiring, improper or broken.
d. Control transformer defective.
a. Close disconnect.
b. Replace fuse.
c. Check wiring diagram or repair.
d. Replace.
Chiller not running. (Power
on light on, high temperature
light on, analyzer gauge
normal)
a. Overload tripped.
b. High pressure switch open (if
supplied).
c. Low water pressure switch
(water cooled).
d. Low oil pressure switch (if
supplied).
e. High suction gas temperature.
a. Allow to cool & reset. Check for
overload.
b. Reset and check for cause.
c. Increase water pressure.
d. Reset and check oil level.
e. Check for high ambient or over-
loaded condition.
Chiller running. (Power on
light on, analyzer gauge
high)
a. High inlet water temperature.
b. High ambient temperature.
c. Dirty or plugged condenser coil.
d. Defective water regulator
(water-cooled)
e. Defective fan control.
f. Defective fan motor.
g. Defective refrigerant
compressor valves.
h. Suction pressure too high.
a. Check heatload.
b. Cool ambient or relocate unit.
c. Clean condenser coil. Blow
with compressed air.
d. Repair or replace.
e. Replace.
f. Replace.
g. Repair or replace compressor.
h. Adjust hot gas bypass valve.
Chiller running (Power on
light on, high temperature
light on, analyzer gauge
pressure low)
a. Leak in refrigerant circuitry.
b. Suction pressure too low.
a. Locate and repair.
b. Adjust hot gas bypass valve.
Check refrigerant charge.

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M. TROUBLESHOOTING GUIDE CONTINUED
SYMPTOM PROBABLE CAUSE REMDY
Chiller running. (Power on
light on, high temperature
light off, analyzer gauge
pressure low)
a. Defective hot gas bypass valve.
b. Defective fan control (low
ambient control).
c. Low ambient termperature.
d. Low refrigerant charge.
a. Replace.
b. Replace.
c. Heat ambient or relocate unit.
d. Repair leak and add refrigerant.
Chiller not running. (Power
on light on, high temperature
light on, analyzer gauge
pressure low)
a. Low pressure switch open.
b. Service valves closed.
c. High suction gas temperature.
a. Check for leak and repair.
b. Open valves.
c. Check for leak.
IMPORTANT: Consult factory before making adjustments on any controls noted in the Trouble-
shooting Guide. The adjustments note must be made by an authorized refrigeration
repair serviceman and are listed as a guide for service personnel. The adjustments
should not be made by unauthorized personnel since all controls are preset at the
factory.

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AIR/TAK WARRANTY POLICY
AIR/TAK products are warranted to be free from defects in materials and workmanship for a period of one year from
date of shipment or up to one year from verified date of installment not to exceed 15 months. Date of installation will
be verified upon receipt of the completed Warranty Registration Card. All Air/Tak refrigerated dryers will additionally
be warranted on parts only (excluding fan motors and drain valves) for a period of two years from the date of shipment.
Also, deliquescent and regenerative air dryer pressure vessels and refrigerated air dryer heat exchangers have a 5-year
prorated warranty.
All damaged pressure vessels and heat exchangers returned to AIR/TAK for warranty consideration must be returned
freight prepaid. Warranty will be determined after factory inspection. Failure to return a damaged heat exchanger or
pressure vessel will result in warranty denial.
Repairs, adjustments, parts, etc. are limited to actual labor cost provided that such defects are promptly reported and
approved following AIR/TAK's warranty procedures. In no event shall the cost of repairs exceed the actual cost of
materials and labor.
AIR/TAK or its representatives reserve the right to decide which warranty items are authorized. AIR/TAK shall not be
liable for incidental or consequential damages which may result from a breach of the warranty described above.
For more information on warranty policies and procedures, contact your authorized AIR/TAK Distributor.
AIR/TAK's line of quality compressed air system products includes:
COMPRESSED AIR SYSTEM FILTERS * AIR-COOLED AFTERCOOLERS
REFRIGERATED AIR DRYERS * CAD COMBINATION AFTERCOOLER DRYER SYSTEMS
RAD-PAK REFRIGERATED AIR DRYER/FILTER PACKAGES * HEATLESS REGENERATIVE AIR DRYERS
HLD-PAK HEATLESS REGENERATIVE AIR DRYER/FILTER PACKAGES
BLOWER PURGE REGENERATIVE AIR DRYERS * EXTERNALLY HEATED REGENERATIVE AIR DRYERS
AIR CHILLERS * FLUID CHILLERS
For an authorized distributor near you, contact Air/Tak at: Air/Tak Inc. 107 West Main Street, Worthington, PA 16262
Phone: [phone] Fax: [phone]
URL: http://www.airtak.com
e-mail: [email protected]