Conair VL Series, VLA-7.5, VLA-10, VLA-15, VLA-20 User Manual
...
Installation
Maintenance
Operation
Troubleshooting
Portable Chillers
VL Series Air-Cooled and Water-Cooled
with Capacities from 2 to 40 tons
The Conair Group, Inc.
One Conair Drive
Pittsburgh, PA 15202
Phone: (412) 312-6000
Fax: (412)-312-6227
UGH021/0301
It’s a good idea to record the model and serial number(s) of
your equipment and the date you received it in the User
Guide. Our service department uses this information, along
with the manual number, to provide help for the specific
equipment you installed.
Please keep this User Guide and all manuals, engineering
prints and parts lists together for documentation of your
equipment.
Date:
Manual Number: UGH021/0301
Serial number(s):
Model number(s):
DISCLAIMER: The Conair Group, Inc., shall not be liable for errors
contained in this User Guide or for incidental, consequential damages in connection with the furnishing, performance or use of this
information. Conair makes no warranty of any kind with regard to
this information, including, but not limited to the implied warranties
of merchantability and fitness for a particular purpose.
Please record your
equipment’s model and
serial number(s) and
the date you received it
in the spaces provided.
Copyright 2001 All rights reserved
THE CONAIR GROUP, INC.
UGH021/0301 VL Series Portable Chillers, 2 to 40 Tons
Page: 3
TABLE OF CONTENTS
1.0 GENERAL 5
1.1 Introduction 6
1.2 Unit location for air cooled models 6
1.3 Unit location for water cooled models 6
1.4 Efficiency 6
1.5 Safety 7
1.6 Clean air act 7
1.7 Miscellaneous 7
Chiller features identified 8
2.0 INSTALLATION 9
2.1 General 10
2.2 To and From process connections 10
2.3 Water supply connection 11
2.4 Air cooled condenser 11
2.4 Water cooled condenser 13
2.5 Electrical connection 13
3.0 OPERATIONS 17
3.1 General 18
3.2 Start up/operations procedure 18
3.3 Instrument operation 23
3.4 Shut down procedure 26
4.0 TROUBLESHOOTING 27
4.1 Sensors 28
4.2 Process pump 28
4.3 Compressor 28
4.4 Blower/fan 28
4.5 Low flow 28
4.6 High Pressure 29
4.7 Low pressure 29
4.8 Freezestat 29
4.9 Oil pressure 30
4.10 Crankcase heater 30
4.11 Electronics 30
5.0 MAINTENANCE 31
5.1 Warranty service procedure 32
5.2 Periodic preventative maintenance 32
5.3 Special maintenance 33
5.4 Solenoid valve service 34
5.5 Pump seal service 36
5.6 Checking the refrigerant charge 39
5.7 Proper cleaning procedure for brazed plate evaporators 40
6.0 COMPONENTS 43
6.1 Water system 44
6.2 Refrigeration system 44
Page: 4
7.0 RELATED DRAWINGS 47
7.1 VLA-5/7.5/10 mechanical schematic 48
7.2 VLA-15/20/25/30 mechanical schematic 49
7.3 VLA-5 physical 50
7.4 VLA-7.5/10 physical 51
7.5 VLA-15/20/25/30 physical 52
7.6 Duct schematic for air cooled chillers 53
7.7 VLA-5/ 7.5/ 10 electrical 54
7.8 VLA-15/ 20/ 25/ 30 electrical 55
7.9 VLW-5/7.5/10 ton mechanical schematic 56
7.10 VLW-15/20/25/30 ton mechanical schematic 57
7.11 VLW-5/7.5/10 physical 58
7.12 VLW-15/20/25/30 ton physical 59
7.13 VLW-5/ 7.5/ 10 ton electrical 60
7.14 VLW-15/ 20/ 25/ 30 ton electrical 61
8.0 APPENDIX 63
8.1 Specifications 64
8.2 Operations below 48°F 66
8.3 Water quality control 68
8.4 Inhibited propylene glycol 68
8.5 Maintaining proper water flow 70
8.6 Low flow bypass circuits 71
8.7 Overhead piping kit 72
8.8 Chiller capacity and derate chart 73
8.9 Pressure-temperature chart for R-22 refrigerant 74
8.10 Engineering formulas 75
8.11 Spare parts list- water-cooled models 76
8.12 Spare parts list- air-cooled models 77
A-1 Service Information 79
A-2 Warranty information 80
UGH021/0301 VL Series Portable Chillers, 2 to 40 Tons
UGH021/0301 VL Series Portable Chillers, 2 to 40 Tons
Page: 5
1.0 GENERAL
1.1 INTRODUCTION
1.2 UNIT LOCATION FOR AIR COOLED MODELS
1.3 UNIT LOCATION FOR WATER COOLED MODELS
1.4 EFFICIENCY
1.5 SAFETY
1.6 CLEAN AIR ACT
1.7 MISCELLANEOUS
Page: 6
VL Series Portable Chillers, 2 to 40 Tons UGH021/0301
1.1 INTRODUCTION
A. This manual covers most ‘VL’ series portable chiller models. Most
‘VL’ series portable chillers are basically identical with exception of
the type of condenser (air cooled or water cooled).
B. All instructions in this manual apply to most ‘VL’ series portable
chiller models regardless of the type of condenser or
instrumentation. Specific instructions relating only to air cooled
condensers, water cooled condenser, or instrumentation are
identified and should be noted by the operator.
C. When calling for assistance from the Conair Service Department, it
is important to know the model and serial number of the particular
unit. The model number encodes critical unit information which is
helpful in any attempt to troubleshoot operating difficulties. The
serial number allows the service team to locate manufacturing and
testing records which can have additional information relating to a
particular unit.
1.2 UNIT LOCATION FOR AIR COOLED MODELS
A. The ‘VL’ air cooled portable chiller is designed for indoor use only.
For most efficient operation, locate the chiller in a clean, dry and
well ventilated environment.
B. The ‘VL’ air cooled portable chiller has an air cooled refrigerant
condenser. For air cooled condensers, a motor driven fan (on
models from 2 to 10 tons) or a centrifugal blower (on models from
15 to 30 tons) generates air flow through the condenser to remove
heat from the refrigerant system. The air cooled condenser on the
‘VL’ portable chiller will discharge a maximum of 15,000 BTU’s per
hour per ton of cooling.
C. The ‘VL’ air cooled portable chiller must have a minimum entering
air temperature of 60°F and a maximum entering air temperature of
95°F for efficient operation.
D. The ‘VL’ air cooled portable chiller must have a minimum of two
feet clearance at the air intake and six feet at the vertical exhaust air
discharge.
1.3 UNIT LOCATION FOR WATER COOLED MODELS
A. The ‘VL’ water cooled portable chiller is designed for indoor use
only. For most efficient operation, locate the chiller in a clean, dry
and well ventilated environment.
1.4 EFFICIENCY
A. Long term efficiency of operation is largely determined by proper
maintenance of the mechanical parts of the unit and the water
UGH021/0301 VL Series Portable Chillers, 2 to 40 Tons
Page: 7
quality. Conair recommends filtering where required to prevent
solids from plugging critical parts (pumps, heaters, seals for
example). Conair highly recommends the services of a competent
water treatment specialist be obtained and his recommendations
followed. Conair accepts no responsibility for inefficient operation,
or damage caused by foreign materials or failure to use adequate
water treatment.
1.5 SAFETY
A. It is important to become thoroughly familiar with this manual and
the operating characteristics of the Conair ‘VL’ series portable
chiller.
B. It is the owner’s responsibility to assure proper operator training,
installation, operation, and maintenance of the Conair ‘VL’ series
portable chiller.
C. Observe all warning and safety placards applied to the chiller.
Failure to observe all warnings can result in serious injury or death
to the operator and severe mechanical damage to the unit.
1.6 CLEAN AIR ACT
A. The ‘VL’ series portable chiller contains HVLC-22
(chlorodifloromethane). This is a class 2 substance.
B. Effective July 1, 1992, it is unlawful for any person in the course of
maintaining, servicing, repairing, or disposing of refrigeration
equipment to knowingly vent or otherwise dispose of any class 2
substance used as a refrigerant in the manner which permits such
substance to enter the atmosphere.
C. De minimis releases associated with good faith attempts to
recapture, reclaim or recycle such substance shall not be subject to
the prohibition set forth in the preceding paragraph.
1.7 MISCELLANEOUS
A. The ‘VL’ series portable chiller is designed to circulate temperature
stabilized fluid through the process resulting in process temperature
control.
B. The ability of the ‘VL’ series portable chiller to maintain process
temperature control is significantly affected by the method of
installation as outline in section 2 of this manual.
C. If the operator has any questions concerning the location and
operation of the ‘VL’ series portable chiller, contact the Conair
Service Department at 800-458-1960 or 814-437-6861.
Page: 8
VL Series Portable Chillers, 2 to 40 Tons UGH021/0301
To Process
Connection
From Process
Connection
Hot Gas
Bypass
Valve
VLA-10
pictured
Compressor
Expansion
Valve
Liquid Line
Solenoid
Refrigerant
Sight Glass
Insulated
Fiberglass
Reservoir
Centrifugal
Pump
Electrical
Cabinet
Galvanized
Steel Frame
Fan Motor
Air Cooled
Condenser
Fiberglass Fan Shroud
Caster
Filter-Drier
To Process
Connection
From Process
Connection
VLW-10
pictured
Condenser Supply
Condenser
Condenser Return
Condenser
Expansion
Valve
Liquid Line
Solenoid
&
Hot Gas
Bypass Valve
&
Filter-Drier
(not visible in
photograph)
Refrigerant
Sight Glass
Insulated
Fiberglass
Reservoir
Centrifugal
Pump
Electrical
Cabinet
Galvanized
Steel Frame
Caster
Compressor
Condenser
UGH021/0301 VL Series Portable Chillers, 2 to 40 Tons
Page: 9
2.0 INSTALLATION
2.1 GENERAL
2.2 TO AND FROM PROCESS CONNECTIONS
2.3 WATER SUPPLY CONNECTION
2.4 AIR COOLED CONDENSER
2.5 WATER COOLED CONDENSER CONNECTION
2.6 ELECTRICAL CONNECTION
Page: 10
VL Series Portable Chillers, 2 to 40 Tons UGH021/0301
2.1 GENERAL
A. All process piping materials (such as hose, rigid piping, valves or
filters) used in process water piping circuitry must be rated for
100°F minimum temperature and 100 PSI minimum pressure.
B. All such materials must have the equivalent or larger diameter of
the particular process connection that length of process water
piping is connected to.
2.2 TO AND FROM PROCESS CONNECTIONS
(see figures 2.2A & 2.2B)
A. Connect the ‘TO PROCESS’ to the ‘water in’ manifold on the mold
or process.
B. Connect the ‘FROM PROCESS’ port to the ‘water out’ port on the
process manifold.
C. Process water piping circuitry should be designed to avoid an
excessive use of elbows and/or lengths of pipe or hose. If hose is
the material of choice, avoid tight twists or curls and excessive
lengths.
D. Valves and filters may be installed in the process water piping
circuitry to facilitate service and maintenance provided that such
devices maintain the full inside diameter of the process connection.
If installed, all such devices must be open and clean during unit
operation.
To process connection:
connect to “water in” on process manifold
From process connection:
connect to “water out” on process manifold
Condenser water in
connection:
connect to tower or city water supply
Condenser water out
connection:
connect to tower or city water return
Water supply connection:
(not shown on this unit)
connect to plant’s city water source
Figure 2.2A
Typical process connections
for water cooled chiller
UGH021/0301 VL Series Portable Chillers, 2 to 40 Tons
Page: 11
To process connection:
connect to “water in” on process manifold
From process connection:
connect to “water out” on process manifold
Water supply connection:
(not shown on this unit)
connect to city water source
Figure 2.2B
Typical process connections
for air cooled chiller
2.3 WATER SUPPLY CONNECTION
A. The automatic water supply make-up system continually monitors
the reservoir tank and fills it when needed. Connect as follows:
1. Connect the chiller’s ‘WATER SUPPLY’ port to the plant’s
city water source.
2. Minimum water supply pressure requirement is identified
on the equipment data plate. This is normally 20 psi.
3. Be certain to use a water supply line equipped with a back
flow prevention device to prevent contamination of potable
water.
2.4 AIR COOLED CONDENSER
A. Air cooled condensers require ambient air temperatures between
60°F and 95°F for efficient operation. Operating above above 95°F
may result in elevated condensing pressures and eventual shutdown on the high pressure safety switch. In such cases, a water
assist unit may be necessary for operations. Air temperatures below
60°F may result in below normal condensing pressures and poor
condensing. In such cases, a low-ambient damper assembly is
required. Check with the Conair service department for more
information on operating with ambients air temperatures above
95°F or below 60°F.
Page: 12
VL Series Portable Chillers, 2 to 40 Tons UGH021/0301
B. Air flow is generated by the motor
driven fans (figure 2.4A) or
centrifugal blowers (figure 2.4B). Air
flow is from the outside of the
chiller, through the condenser and
exhausted through the top of the
unit. On centrifugal blowers models,
exhaust air can be ducted outside of
the plant’s interior environment.
Special duct work is required and a
HVAC contractor should be
consulted for sizing and material
specifications. Exhaust air can not be
ducted on motor driven fan models.
C. A free air space of at least two (2)
feet is required at the condenser
intake and six (6) feet at the
condenser discharge to allow for
proper air flow.
D. At full load, the chiller will discharge
approximately 15,000 BTU’s per
hour per ton of cooling.
E. On blower units, air discharge
duct work should be sized by
a qualified HVAC engineer.
Sizing shall be according to
rated VLM at the static
pressure of .90 inches of
water. See figure 2.4C at right.
F. On blower units, a damper
control assembly is required in
low ambient
temperature areas or
when outdoor air
make-up is used. The
assembly works in
conjunction with
refrigerant head
pressure to regulate
air flow to maintain
proper refrigerant
head pressure when
condenser intake air
temperature will be
less than 60°F. See
figure 2.4D to the
right.
Figure 2.4C
Figure 2.4D
Figure 2.4A
Typical fan assembly
Figure 2.4B
Typical blower assembly
MODEL CFM
VLA-15 15,000
VLA-20 20,000
VLA-25 25,000
VLA-30 30,000
CFM RATINGS
Damper assembly
1/4" copper line connection
Angle valve and cap
Punch hole
in top panel
1/4" Copper line
Liquid receiver
(located inside
chiller on base)
UGH021/0301 VL Series Portable Chillers, 2 to 40 Tons
Page: 13
2.5 WATER COOLED CONDENSER CONNECTION
A. Connect the ‘CONDENSER WATER
IN’ port to the plant’s city water
supply or tower system supply.
1. Required consumption from
a city water source is 1.5
gpm at 65°F per ton of
rated capacity.
2. Required consumption for a
tower water source is 3 gpm
at 85°F per ton of rated
capacity.
B. Connect the chiller’s ‘CONDENSER
WATER OUT’ port to the plant’s
drain or tower system return.
1. Note: if dumping to the
plant’s open drain, drainage
shall be done according to
local codes.
C. The pressure differential requirement
between the condenser “water in”
and the condenser “water out” lines
must be 30 psi for adequate efficiency.
D. The installation of a strainer in the condenser “water in” line is
recommended. This removes solids from the water supply and
serves to protect the water saver (regulator) valve.
E. An optional water saver (regulator) valve may be installed in the
condenser “water in” line. During winter months, or cold seasons,
the valve will throttle the water flow through the condenser. The
amount of flow is based on the refrigerant head pressure and the
regulator will modulate the valve’s orifice to maintain a head
pressure of 210 psig for best efficiency.
2.6 ELECTRICAL CONNECTION
A. NEMA 1 MODELS
1. Electrical power supply requirements for Nema 1 units are
identified on the equipment data plate. Determine the
plant’s voltage supply is the same as the unit’s voltage
requirements. WARNING: Do not connect the unit to a
voltage supply not equal to the unit’s voltage
requirements as specified on the unit’s data plate. Use
of incorrect voltage will void the unit’s warranty and
Figure 2.5A
Condenser connections 30 ton unit - optional regulator
valve shown
Figure 2.5B
Condenser connections 10 ton unit- optional regulator
valve shown
Page: 14
VL Series Portable Chillers, 2 to 40 Tons UGH021/0301
cause a significant hazard that may result in serious
personal injury and unit damage.
2. A customer supplied, four conductor cable is required for
connection to a customer supplied fused disconnecting
means. The fused disconnecting means shall be sized and
installed according to the unit’s power supply requirements
and local electrical codes. See figure 2.5A (next page) for
details on water cooled power cable routing.
3. Connect the four conductor power cable to power entry
terminal block on the unit’s electrical panel. Then connect
the power cable to the fused disconnect switch.
B. NEMA 12 MODELS
1. NEMA 12 units are constructed with a dust tight electrical
enclosure and branch circuit fusing. Electrical power supply
requirements are identified on the equipment data plate.
Determine the plant’s voltage supply is the same as the
unit’s voltage requirements. WARNING: Do not connect
the unit to a voltage supply source not equal to the
unit’s voltage requirements as specified on the unit’s
data plate. Use of incorrect voltage will void the unit’s
warranty and cause a significant hazard that may result
in serious personal injury and unit damage.
2. Appropriate conduit and fittings should be selected which
will maintain the integrity of the cabinet.
3. Supply a power conductor sized according to the unit’s
power supply requirements. Connect the power conductor
to the unit’s power supply entry terminal block or the fused
disconnect switch. Some Nema 12 models may be supplied
with an optional disconnect switch. The owner supplied
fused disconnecting means shall be sized and installed
according to the unit’s power supply requirements and
local electrical codes.
C. CONTROL CIRCUIT WIRING
1. The unit’s supplied control circuit is 110 volt, 1 phase, 60
cycle. The control circuit is supplied by the factory installed
transformer. An inline control circuit fuse is provided.
D. GENERAL
1. Make certain all ground connections to the unit are
properly affixed.
2. Make certain power conductor, disconnecting means, and
fusing are properly sized according to the unit’s power
supply requirements.
UGH021/0301 VL Series Portable Chillers, 2 to 40 Tons
Page: 15
3. Make certain all electrical connections are tightly affixed.
Any loose wiring connections must be tighten before
engaging the power supply.
4. Make certain no moisture or standing water is present
inside the electrical cabinet (figure 2.5B).
Refrigerant High
Pressurestat
Refrigerant Low
Pressurestat
Fuse Block
Transformer
Power Entry
Freezestat
Cabinet Door
Figure 2.6B Typical electrical cabinet detail.
Motor Starter
Overload Relay
Compressor Starter
Figure 2.6A
5 THRU 10 TON MODELS
ELECTRICAL CABINET
MICROPROCESSOR
CONTROLLER
5 THRU 10 TON MODELS
WATER COOLED
WATER COOLED
ROUTE POWER CORD
OUT OPEN BACK OF UNIT
TO DISCONNECT
ELECTRICAL CABINET
MICROPROCESSOR
CONTROLLER
WATER COOLED
WATER COOLED
15 THRU 30 TON MODELS
15 THRU 30 TON MODELS
TO DISCONNECT
ROUTE POWER CORD
OUT OPEN BACK OF UNIT
VL Series Portable Chillers, 2 to 40 Tons UGH021/0301
Page: 16
THIS PAGE INTENTIONALLY BLANK
UGH021/0301 VL Series Portable Chillers, 2 to 40 Tons
Page: 17
3.0 OPERATIONS
3.1 GENERAL
3.2 START UP/OPERATIONS PROCEDURE
3.3 INSTRUMENT/OPERATION
3.4 SHUT DOWN PROCEDURE
Page: 18
VL Series Portable Chillers, 2 to 40 Tons UGH021/0301
3.1 GENERAL
A. Failure to follow the factory required operations procedure may
adversely affect the unit’s ability to adequately control process
temperature and may create a hazardous operating condition
which may result in serious operator injury and/or unit damage.
B. IMPORTANT: each chiller is equipped with a crankcase heater on
the compressor. While the compressor is idle, the crankcase heater
prevents freon vapor from migrating to and condensing in the
compressor crankcase. If freon is allowed to condense in the
crankcase, it can be drawn into the cylinders upon start up. This
can cause catastrophic damage to the connecting rods, pistons,
and valve plates. To avoid this, BEFORE THE UNIT IS STARTED,
THE POWER SUPPLY SHOULD BE APPLIED TO THE UNIT FOR AT
LEAST 12 HOURS, OR UNTIL THE BOTTOM OF THE
COMPRESSOR IS WARM TO THE TOUCH. If the power has been
disconnected more than two hours, the power should be applied
for six hours before restarting. Power should be applied to the unit
continuously, except for service purposes. The crankcase heater
should be checked for proper operation on a regular basis.
C. The OPERATIONS segment of this manual is divided into the
following sections:
3.2 Start up/operations - follow this segment to start the unit
after the initial install to the process system or to restart the
unit after reinstallation to the same or different process
system. This section includes information on system fill,
electric motor phasing (pump rotation) and process flow
adjustments.
3.3 Instrument - follow this segment to start up and operate
the instrument. This section includes information on
setpoint selection and adjustment, and feature
explanations.
3.4 Shut down procedure - follow this segment to shut down
the unit. This segment includes information on system shut
down, electrical power supply precautions, and
disconnection from system.
3.2 START UP/OPERATION PROCEDURE
A. SYSTEM FILL
1. The VL series portable chiller has an internal reservoir which
must be filled and maintained for proper operation. All VL
series chillers have a level switch mounted at the proper
water level in the reservoir.
UGH021/0301 VL Series Portable Chillers, 2 to 40 Tons
Page: 19
2. Conair recommends the addition of 20% inhibited
propylene glycol to the process fluid. This should help
prevent the process fluid from freezing and internal
components from rusting. A biocide must be added to the
water to prevent organism growth in the chilled water
system. See water treatment section in section 8 of this
manual for more information.
3. FOR AUTOMATIC FILL (IF
EQUIPPED): engage the
water supply to unit. The
level switch will activate the
make-up solenoid (figure
3.2A), which will open and
the water supply will fill the
reservoir tank. During
operations, with the water
supply source “on”, the unit
will automatically maintain
the correct reservoir level.
4. MANUAL FILL: disconnect the electrical power supply and
remove all necessary cover panels to access the reservoir
tank. Add fluid directly to the reservoir tank. When the
pump is first started, as process lines are filled and air is
purged, additional fluid may be required to restore the
reservoir to the correct level.
B. ELECTRIC MOTOR PHASING (PUMP ROTATION)
1. The operator must determine the unit is phased correctly.
This is done by visually inspecting the rotation of the pump
motor shaft and is outlined below. Incorrect phasing results
in poor operation and eventual damage to the unit.
a. Supply electrical power to the unit by engaging the
unit’s disconnect switch. Once the correct voltage
is supplied to the unit, the POWER light on the
unit’s instrument display will illuminate.
b. Remove the necessary covers panel to access the
pump motor. Note that electrical power is
engaged at this point and caution must be
observed while the electrical supply is engaged
and cover panels are removed.
c. Locate the electric motor (figure 3.2B) The operator
must identify the motor shaft inside the electric
motor housing. The motor shaft can be seen
through the vent slots in the motor housing or by
removing the shaft cover (figure 3.2C).
Figure 3.2ATypical make-up solenoid valve
Page: 20
VL Series Portable Chillers, 2 to 40 Tons UGH021/0301
d. Toggle the CHILLER
ON switch. This will
quickly cycle the
electrical motor
“on” and then “off”.
e. Observe the motor
shaft. When the
CHILLER ON switch
is turned “on”, the
motor shaft will
rotate. When the
CHILLER ON switch
is turned “off”, the
motor shaft will
slowly “coast” to a
stop. As the shaft
slows to a stop, the
operator must
identify its rotation.
Correct rotation
(correct phase) is
“clockwise”, when
viewed from the
rear of the motor.
Incorrect rotation is “counterclockwise” (incorrect phase) when viewed from the
rear of the motor. If the shaft does not rotate when
the PUMP switch is toggled, the operator must
identify the cause as outlined in this manual’s
troubleshooting and repair section.
f. If the motor shaft is phased correctly (shaft turns in
a clockwise direction), continue with step C. If the
motor shaft is NOT phased correctly (shaft turns in
a counter-clockwise direction), continue the
procedure with step 2.
2. If the motor shaft is NOT phased correctly, the operator
must:
a. Disengage the electrical power supply to the unit at
the disconnect switch. Follow proper lockout
procedures before proceeding. Verify the POWER
light on the instrument display is off.
b. With the electrical power supply is disengaged,
reverse any two power leads of the power cord at
the disconnect terminals.
c. Note: reversing any two power leads of the power
cord will correctly phase an incorrectly phased
Figure 3.2C
Motor shaft
Vent slots
Figure 3.2B
Electric motor
Pump
UGH021/0301 VL Series Portable Chillers, 2 to 40 Tons
Page: 21
power supply. The operator must reverse the
power leads at the disconnect switch only and
NOT at the power entry terminals on the unit’s
electrical panel. The unit’s internal electrical
system wiring is phased correctly at the factory and
must not be altered in the field.
d. Visually inspect the rotation of the motor as
outlined step 1 to determine the unit is phased
correctly.
C. PROCESS FLOW ADJUSTMENTS
1. The operator must determine and set proper water flow
rate for the most efficient and trouble free operation.
a. Water flow rate through the process is determined
by the pressure losses in the process loop.
Generally, higher flow rates result in turbulent flow
achieving maximum temperature control and lower
maintenance. Since the evaporator in most liquid
chillers is flow sensitive, the efficiency of operation
is directly related to the flow of liquid.
b. Maximum chiller efficiency is obtained at
approximately 2.4 gpm per ton of rated capacity.
Low liquid flow can reduce efficiency and in some
cases allow ice to form in the evaporator which can
damage the evaporator. Excessive flow will trip the
motor overload protection circuit.
2. Activate the CHILLER ON rocker switch on the display to
activate the process pump. Wait a few moments to allow air
to be purge from system. Two items the operator must look
for are low or excessive flow conditions.
3. LOW FLOW... to allow operation under a low flow
condition, it is necessary to install a flow bypass system in
the process circuitry. This will allow a portion of the flow to
bypass the process and return directly to the chiller. This
keeps the total flow above the cutoff point. Figure 3.2D
illustrates a typical bypass loop.
Figure 3.2D Typical low flow by-pass loop
21 GPM 5 GPM
BYPASS
CHILLER PROCESS
THROTTLING
VALVE 16 GPM
5 GPM21 GPM
Page: 22
VL Series Portable Chillers, 2 to 40 Tons UGH021/0301
4. EXCESSIVE FLOW... excessive
flow can overload the
process pump motor and
cause eventual failure. This is
a result of the process loop’s
ability to flow water at a
great rate than can be
provided by the process
pump. This eventually
results in tripping the
thermal motor overload
relay (overload relays open)
and the unit will shut down.
a. If an excessive flow situation is encountered and
the motor overload circuit has tripped, the operator
must manually reset the overload relay (figure 3.2E)
before operations can continue. This is done by
opening the electrical panel cover, identifying the
reset lever on the overload relay, and pushing the
reset lever “in” until the overloads are reset
(evidenced by a “clicking” sound as the overloads
reset).
5. To overcome an excessive flow condition, the operator
should set the process flow rate according to the motor
amperage:
a. Remove electrical cover panel. Note that the
electrical power is engaged at this point and
caution must be observed while the cabinet
panel is open.
b. Identify the motor
starter block. This
block consists of
the motor starter
contactor and the
overload relay.
c. Place an amp
meter on a single
power lead
emanating from
the overload relay.
d. Locate the electric pump motor. Identify
the motor name plate on the motor housing (figure
3.2F). The full load amp rating for the motor is
listed on the name plate.
e. Engage the electrical power supply and start the
motor by switching ‘on’ the CHILLER ON rocker
switch.
Figure 3.2E
Reset level on overload relay
Motor name plate
Figure 3.2F
UGH021/0301 VL Series Portable Chillers, 2 to 40 Tons
Page: 23
f. The amp meter will display the motor amps.
Compare the actual motor amps as displayed on
the amp meter to the full load amp rating as listed
on the motor name plate.
g. If the amp draw is excessive (higher than the listed
name plate amp rating), a throttling valve must be
installed in the “from process” circuit line. The
preferred throttling valve is a ball valve.
h. With the throttling valve installed, fully close the
valve and then engage the pump. Slowly open the
throttling valve and monitor the motor amps as
displayed on the amp meter until the actual motor
amps equals the listed full load amp rating of the
motor.
3.3 INSTRUMENT OPERATION
A. INSTRUMENT START-UP
1. When the correct electrical power and adequate water
supply pressure are supplied to the unit, it is possible to
start the unit for temperature control duty.
2. When the electrical power supply is engaged to the unit,
the instrument (figure 3.3A) will momentarily illuminate all
indicating lights and digits on the display head. After a
short delay, the instrument will display the software version
number. At this time, the operator can verify that all lights
and digits are functioning properly. If the operator
VL Chiller Control
Power
Pump
Compressor
Hot Gas Bypass
Temperature
To Process
Setpoint
On
Off
Page: 24
VL Series Portable Chillers, 2 to 40 Tons UGH021/0301
determines an indicating light or digit does not illuminate,
the instrument must be removed and sent to the factory for
repair. When power is supplied to the unit, the POWER
light will illuminated.
3. Toggle ‘on’ the CHILLER ON rocker switch to activate the
chiller. The operator can stop process operations
(refrigerant and coolant circuits) by switching ‘off’ the
CHILLER ON switch.
4. To select the operating setpoint, use the SELECT key to
index through the TO PROCESS and SET POINT
temperature functions until the SET POINT light is
illuminated.
5. When the SET POINT light is illuminated, the setpoint
temperature is shown in the temperature display window.
Use the UP and DOWN ARROW keys to change the
setpoint temperature.
6. PRECAUTIONS: the instrument is programmed from the
factory with a setpoint range of 48° to 70°F. To operate
below 48°F, the addition of inhibited propylene glycol and
modification of the safety control settings are required.
Diligent monitoring of the water/glycol solution is
mandatory to prevent freezing of the evaporator. Freezing
may cause the evaporator to rupture allowing water and
freon to mix which will cause major damage to the
refrigeration system. Operating above 70°F requires the
addition of a refrigerant crankcase pressure regulating (CPR)
valve. The CPR valve is necessary to prevent overloading of
the compressor which can cause premature failure. Contact
your local refrigeration contractor or the factory for further
information. The operating range of the instrument may be
changed to 20°F - 90°F by adjustment of the CPU DIP
switch. Refer to the technical section of this manual for
more information. The instrument is set up from the factory
to give an alarm light and a 115 volt alarm output if the
temperature to process deviates more than 10° from the
setpoint.
7. After selecting the setpoint temperature, the operator may
leave the display in the SET POINT state. The display will
automatically return to the TO PROCESS temperature state
after twenty seconds of inactivity.
8. The operator can stop operations by switching ‘off’ the
CHILLER ON rocker switch. This will disengage the
refrigerant and coolant circuits.
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