Page 1
SMC-050 to SMC-150 Series
0.5 to 1.5 hp Portable Chillers
Operation and Installation Manual
Sterling, Inc./Sterlco
P. O. Box 245018
5200 West Clinton Avenue
Milwaukee, WI 53224-9518
Tel (414) 354-0970
Fax (414) 354-6421
Part No. A0544325 Bulletin No. SC2-615.1
Page 2
Sterling/Sterlco is committed to a continuing program of product improvement.
Specifications, appearance, and dimensions described in this manual
are subject to change without notice.
© Copyright Sterling/Sterlco and Sterling, Inc. 2003
All rights reserved. Effective 7/30/2003
Part No. A0544325 Bulletin No. SC2-615.1
Page 2
SMC Series Chillers
Page 3
Safety Considerations
SMC Series Chillers are designed to provide safe and reliable operation when installed and
operated within design specifications, following national and local safety codes.
To avoid possible personnel 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.
; 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. It is a good
idea to remove the fuses and carry them with you.
; Make sure the chiller is properly GROUNDED before switching power on.
; When welding or brazing in or around this equipment, be 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.
; The refrigeration system can develop refrigerant pressures in excess of 500 psi (3,450 kPa).
DO NOT CUT into the system without first relieving pressure.
; Do not jump or bypass any electrical safety control.
; Do not restore power until all tools, test equipment etc. have been removed and the panels
replaced.
; Only PROPERLY TRAINED personnel familiar with the information within this manual
should work on this equipment.
SMC Series Chillers Page 3
Page 4
Table of Contents
1 General Information ................................................. 7
1-1 Introduction
1-2 Necessary Documents
1-3 Models Covered
1-4 Available Options
1-5 Uncrating Your New Chiller
1-6 In the Event of Shipping Damages
1-7 If the Shipment is Not Complete
1-8 If the Shipment is Incorrect
1-9 Returns
2 Chiller Installation .................................................. 13
2-1 Electrical Connections
2-2 Process Water Connections
2-3 SMC Condenser Air Supply
2-4 Water Reservoir
2-5 Overhead Process Considerations
3 Sequence of Operation.......................................... 17
3-1 Chilled Water Circuit
3-2 Refrigeration Circuit
3-3 High Pressure Cutout
3-4 Low Pressure Cutout
3-5 Remote Start/Stop Interlock
Page 4
SMC Series Chillers
Page 5
Table of Contents
4 Startup Checklists.................................................. 23
4-1 Introduction
4-2 SMC Pre-Startup Checklist
4-3 SMC Startup Checklist
5 Microprocessor Control ........................................ 25
5-1 Introduction
5-2 Setting the Process Water Temperature
5-3 Setting the Alarm Value
6 Optional Graphic Panel ......................................... 27
6-1 Indicator Lights
6-2 Switches
7 Routine Maintenance ............................................. 29
7-1 Lubrication
7-2 Condenser Maintenance
8 Troubleshooting Guide.......................................... 33
SMC Series Chillers Page 5
Page 6
Charts and Figures
1
SMC050A Process Pump Curves 10
2
SMC100A Process Pump Curves 10
3
SMC150A Process Pump Curves 11
4
SMC Series Chiller Specifications 12
5
Ethylene Glycol Curve 15
6
Overhead Piping 16
7
SMC Component Identification 19
8
Piping Schematic — 1 Pump with Reservoir 20
9
10
11
12
13
14
15
16
17
Piping Schematic — 1 Pump without Reservoir 21
Piping Schematic — No Pump, No Reservoir 22
SMC Water Circuit Pressure Drop Table 24
SMC Control 26
Optional Graphic Panel 28
Typical SMC Subpanel 29
Typical SMC Wiring Schematic 30
SMC Wiring Schematic for Chillers with No Pump or Reservoir 31
SMC Spare Parts List 35
Page 6
SMC Series Chillers
Page 7
1 General Information
1-1 Introduction
SMC Series Water Chillers are reliable, accurate, and easy-to-use air cooled chillers designed for
use with water/glycol. Standard range of operation is 30°F (-1°C) to 65°F (18°C). A crankcase
pressure regulating valve option is available for processes requiring a leaving water temperature
of up to 75°F (24°C). SMC models are available in ½ hp (373 W), 1 hp (746 W), and 1½ hp
(1,118 W) models and have an internal six gallon (23 liter) reservoir. All models are self
contained, fully assembled, and shipped ready to use.
A properly installed, operated, and maintained SMC Series Chiller will provide many years of
reliable operation. To get the most satisfaction from your new chiller, read and follow the
instructions in this manual.
1-2 Necessary Documents
The following documents are necessary for the operation, installation and maintenance SMC
Series Chillers. Additional copies are available from Sterlco. Familiarize the appropriate
personnel with these documents:
; This manual.
; The electrical schematic and connection diagram mounted inside the control enclosure.
Typical schematics for general reference are provided in Figures 14 and 15 on Pages 32 and
33.
; The operation and installation manuals for installed accessories and options.
; The Customer Parts List included in the information packet.
1-3 Models Covered
This manual provides operation, installation, and maintenance instructions for SMC Series
Chillers. Model numbers are on the serial tag. Please know the model number, serial number and
operating voltage of your chiller if you need to contact Sterlco.
SMC Series Chiller models are designated by approximate compressor horsepower. A SMC050
chiller has a ½ hp (373 W) compressor, a SMC100 chiller has a 1 hp (746 W) compressor, and a
SMC150 chiller has a 1½ hp (1,118 W) compressor.
SMC Series Chillers Page 7
Page 8
1-4 Available Options
SMC Series Chillers are available with options that tailor the unit to your requirements. Some are
factory installed, some can be retrofitted in the field. Consult your local Sterlco Sales
Representative. Some of these options are:
Special Pumps
Special pump options are available for greater pressure and flow rates. Bronze and stainless steel
wetted surface standard flow pumps ranging from 30 psi (207 kPa) to 60 psi (414 kPa) are
available.
Reservoirs
SMC Series Chillers are available without a reservoir for processes that use their own reservoir.
Power Cord
A 10 foot (3 meter) power cord is available to speed SMC installation.
Casters
Four 2-inch (5 cm) swivel casters add mobility to the SMC unit.
CPR Valve
A crankcase pressure regulating (CPR) valve is available for leaving water temperatures up to
75°F (24°C).
1-5 Uncrating Your New Chiller
SMC Series Chillers are shipped mounted on a skid, enclosed in a plastic wrapper, and open
crated on all four sides and top.
; Pry the crating away from the skid and remove. Use a pry bar to remove the blocks securing
the unit to the skid.
; Lift the unit off the skid with a fork truck. Insert forks between skid and chiller from the side
until they protrude beyond the opposite side of the unit. The forks must be equidistant from
the center line 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 remove the
skid from the unit.
; Lower slowly. The unit will land on its feet or casters and can be moved into position.
Page 8
SMC Series Chillers
Page 9
1-6 In the Event of Shipping Damages
Important!
According to the contract terms and conditions of the Carrier,
the responsibility of the Shipper ends at the time and place of shipment.
The Carrier then assumes full responsibility of the shipment.
; Notify the transportation company’s local agent.
; Hold the damaged goods and packing material for the examining agent’s inspection. Do not
return any goods to Sterlco before the transportation company inspection and authorization.
; File a claim against 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 Sterlco regarding your wish for replacement.
1-7 If the Shipment is Not Complete
Check the packing list. The apparent shortage may be intentional. Back-ordered items are noted
on the packing list. You should have:
; SMC Series Chiller
; Bill of Lading
; Packing List
; Operating and Installation Packet
Re-inspect the container and packing material to see if smaller items have been missed during
unpacking. Determine that the item was not taken from the area before the shipment was checked
in. Notify Sterlco immediately of the shortage.
1-8 If the Shipment is Incorrect
; If the shipment is not what you ordered, contact Sterlco immediately. Include the order
number and item.
; Hold the items until shipping instructions are received.
SMC Series Chillers Page 9
Page 10
1-9 Returns
Do not return any damaged or incorrect items until
you receive shipping instructions from STERLCO.
Important!
Figure 1
SMC050A Process Pump Curves
TOTAL HEAD
MTRS
PSI FEET
49
69 160
37 52 120
24
35 80
12 18 40
U. S. GALLONS
PER MINUTE
LITRES
PER MINUTE
TOTAL HEAD
PSI
MTRS
49
69 160
37 52 120
24
35 80
FEET
BZ050A BZ050B
0.4
1.5
0.8
3.0
1.2
4.5
CURVES REPRESENT PUMP DISCHARGE ADJUSTED FOR INTERNAL BY-PASS
BZ100B
BZ100A
SMC050A - PROCESS PUMPS SELECTIONS
60 HERTZ PUMP CURVE
BZ050C
1.6
6.1
2.0
7.6
2.4
9.1
2.8 3.2
10.6
12.1
Do not extrapolate pump curves.
Figure 2
SMC100A Process Pump Curves
SMC100A- PROCESS PUMPS SELECTIONS
60 HERTZ PUMP CURVE
BZ100C
3.6
13.6 15.1
4.0 4.4
16.7
4.8
18.2
12 18 40
U. S. GALLONS
PER MINUTE
LITRES
PER MINUTE
Page 10
1.6
6.1
2.0
7.6
2.4
9.1
2.8
10.6
3.2
12.1
3.6
13.6 15.1
4.0 4.4
16.7
4.8
18.2
5.65.2 6.0 6.4
19.7 21.2 22.8 24.2
CURVES REPRESENT PUMP DISCHARGE ADJUSTED FOR INTERNAL BY-PASS
Do not extrapolate pump curves.
SMC Series Chillers
Page 11
Figure 3
SMC150A Process Pump Curves
TOTAL HEAD
MTRS
PSI FEET
49
69 160
37 52 120
24
35 80
12 18 40
U. S. GALLONS
PER MINUTE
LITRES
PER MINUTE
SMC150A - PROCESS PUMPS SELECTIONS
60 HERTZ PUMP CURVE
BZ150B
BZ150C
BZ150A
2.42.0
9.17.6
2.8
10.6
3.2
12.1
3.6
13.6 15.1
4.0 4.4
16.7
4.8
18.2
5.2 5.6 6.0 6.4 6.8
19.7 21.2 22.7 24.3 25.8
CURVES REPRESENT PUMP DISCHARGE ADJUSTED FOR INTERNAL BY-PASS
Do not extrapolate pump curves.
SMC Series Chillers Page 11
Page 12
O
No Flow indicator
(for pumpless
units only)
A0537868
NO FLOW
ptional gauge package
Optional gauge package
PUMP
PRESSURE
Mini Chiller
PC Series
Portable Chiller
ON
HIGH
LOW
REFRIGERANT
REFRIGERANT
PUMPONCOMPRESSOR
PRESSURE
PRESSURE
ON
POWER
OFF
Figure 4
SMC Series Chiller Specifications
Power cable entrance,
either side
Side cover
handle
Sight glass
Drain plug
(3/4" NPT)
To Process
(3/4" NPT)
34"
Model
Capacity
@ 65°F
LWT 75°F
Ambient
20"
Front View
Capacity
@ 50°F
LWT 90°F
Ambient
26"
Right Side View
Nominal
Chilled
Water Compressor Pump
18 7/16"
Process
Connection
13 7/16"
Optional Casters
Amp
Draw
230/1/60
From Process
(3/4" NPT)
Dimensions
(inches)
Rear View
Operating
Weight
Shipping
Weight
Number (Btuh) (Btuh) (gpm) (hp) (inches NPT) Running L W H (lbs) (lbs)
1
/
hp,
SMC-050 8,100 4,800 1.2
SMC-100 14,000 9,550 2.4
SMC-150 25,400 16,000 3.6
Model
Capacity
@ 18°C
LWT, 24°C
Ambient
Capacity
@ 10°C
LWT, 32°C
Ambient
Nominal
Chilled
Water Compressor Pump
½
1
1½
3
1.2 gpm @
24 psig
1
/
hp,
3
2.4 gpm @
34 psig
1
/
hp,
3
3.6 gpm @
24 psig
¾
¾
¾
Process
Connection
8A 20 26 34 265 265
10A 20 26 34 325 325
12A 20 26 34 345 345
Amp
Draw
230/1/60
Dimensions
(cm)
Operating
Weight
Shipping
Weight
Number (watts) (watts) (lpm) (watts) (inches NPT) Running L W H (kg) (kg)
224 watts,
SMC-050 2,374 1,407 4.5 373
4.5 lpm
@ 207 kPa
¾
8A 51 66 86 120 120
224 watts,
SMC-100 4,103 2,800 9.0 746
9.0 lpm
@ 234 kPa
¾
10A 51 66 86 147 147
224 watts,
SMC-150 7,444 4,690 13.6 1,118
13.6 lpm
@ 207 kPa
¾
12A 51 66 86 156 156
Page 12
SMC Series Chillers
Page 13
2 Chiller Installation
2-1 Electrical Connections
Check serial tag voltage and amperage requirements and make sure your electrical service
conforms. See Figure 4 on Page 12 for total running amps.
Bring properly sized power leads and ground from a fused disconnect (installed by your
electrician) to the main power terminal in the chiller’s electrical enclosure.
; Electrical connections must comply with all applicable electrical codes.
; The chiller must be grounded in accordance with NEC Article 250.
; Voltage must be within 10% of the chiller’s nameplate rating.
2-2 Process Water Connections
; All external chilled water connections to the process must be of adequate size.
; See Figure 6 on Page 18 for sizing recommendations.
; The largest possible openings and passages should be provided for the flow of chilled water
through platens, dies, molds or other pieces of equipment.
Important!
Keep any pressure drop in external process piping
to an absolute minimum for optimum unit operation.
To Process
Connect the
From Process
Connect the FROM PROCESS chilled water return inlet to the return from the process back into
the chiller for cooling and recirculation.
; Sterlco recommends a strainer on the FROM PROCESS return line.
TO PROCESS chilled water supply outlet to the process being cooled.
SMC Series Chillers Page 13
Page 14
Process Water Bypass
All SMC chillers have an internal bypass device (patent pending). If the process flow becomes
blocked during chiller operation, this component allows water to flow through the chiller. This
protects the chiller from freeze-up, excessive pressures, and pump damage, and allows other
safety features to remain effective.
2-3 SMC Condenser Air Supply
SMC chillers use the surrounding air to cool the condenser.
; Condenser air entering the SMC unit should be at least 65°F (18°C). Operation with air
below 65°F (18°C) can cause the low pressure cutout to shut down the chiller due to the low
refrigerant pressure.
; Install the chiller in an area where there is free passage of air for condensing.
; Provide 18” (46 cm) or more clearance for the chiller’s air intake.
; Make provisions to exhaust the heated air discharged from the chiller.
; Do not put the SMC unit where steam, hot air or fume exhausts will be drawn into the
condenser.
; Air-cooled condensers must be cleaned frequently. Neglect reduces capacity, increases
operating costs, and leads to possible chiller failure. See Chapter 7 on Page 31 for cleaning
instructions.
; Normal condensing pressure with 95°F (35°C) air is approximately 180 psi (1,241 kPa) for
the SMC050A and SMC100A; 275 psi (1,897 kPa) for the SMC150A.
SMC Ambient Temperature Ranges
Ambient temperature range Minimum temperature Maximum temperature
Operation 65°F (18°C) 100°F (38°C)
Storage 40°F (4°C) 120°F (49°C)
2-4 Water Reservoir
During startup and when additional solution is required, see Figure 5 on Page 17 for the
recommended ethylene glycol/water solution. This chart shows the proportions needed to
provide freeze protection to 20°F/°C below the desired process setpoint.
; Add a pre-mixed solution to provide freeze protection to a temperature 20°F/°C below the
normal operating temperature of the chiller.
; Use industrial quality (not automotive) ethylene glycol.
Page 14
SMC Series Chillers
Page 15
; A corrosion inhibitor suitable for the materials in the system should be added to the
Ethyl
d
glycol/water solution.
; If straight water use is desired, contact the Sterlco Engineering Department.
; The six gallon (23 liter) reservoir is not designed to withstand water pressure above 5 psi (34
kPa).
; The fill opening and vent line must be vented to the atmosphere for proper operation.
Figure 5
Ethylene Glycol Curve
ene glycol require
for evaporator freeze protection
30%
Ethylene
glycol
percent
by
volume
20%
10%
0%
0º 30º 40º 50º 60º 70º
Chilled water
operating temperature °F
(set point)
Normal operating range is between 30°F and 70°F
SMC Series Chillers Page 15
Page 16
2-5 Overhead Process Considerations
V
V
If your application has chilled water or process piping above the reservoir fill and vent level,
install a standpipe to a point 1’ (30 cm) above the highest point in the system.
In applications where the process or its piping is 15 feet (4.6 m) or more above the reservoir, you
must take steps to prevent over-pressurization of the reservoir. This condition can occur on
system shutdown when the water in the system drains into the reservoir.
To prevent this, install a check valve in the unit TO PROCESS line and a vacuum breaker at the
high point of the return FROM PROCESS line. See Figure 6 on Page 18 for more information.
Note: The reserve capacity of the reservoir can hold a volume equal to 20 feet (6.1 m) of 1-inch
(2.5 cm) pipe.
Figure 6
Overhead Piping
The reservoir vent & fill line
to be piped 12" above the highest
point of the system. The vent line
must remain open to the atmosphere.
ent
12"
1/4"
Strainer
Add check valve
if system piping
extends 15 feet
above reservoir.
acuum Breaker
Check
Valve
Process Return
Process Supply
Assembly
Cap
1/8"
Hole
6" Min.
Indicates end of STERLCO piping
Page 16
SMC Series Chillers
Page 17
3 Sequence of Operation
Important!
• The SMC unit has a leaving water temperature range of 30°F (-1°C) to 65°F
(18°C). Do not attempt to run the SMC unit outside this temperature range or
damage to the unit may occur.
• When operating the SMC unit between 30°F (-1°C) and 40°F (5°C), you must
use a solution of 75% water and 25% industrial-grade ethylene glycol with a
suitable corrosion inhibitor to protect the SMC unit from freeze-up. See
Figure 5 on Page 17 for more information. Such damage is not covered by
the Sterlco warranty.
3-1 Chilled Water Circuit
Figures 8, 9, and 10
; Process cooling water supply and return connections are made at the pipe stubs at the rear of
the chiller.
; Warm water returns from the process and enters the reservoir tank.
; The process water is pumped through the evaporator where it is cooled.
; The coolant flows to the process and returns to repeat the cycle.
; A chilled water bypass assembly (patent pending) between the supply and return lines
guarantees a constant flow through the evaporator during intermittent low or no-flow
conditions.
; A flow switch in units without pumps will prevent the compressor from running without
adequate flow through the evaporator
3-2 Refrigeration Circuit
Liquid refrigerant from the condenser passes through a filter/dryer which removes moisture
and other contaminants.
The refrigerant then passes through the thermal expansion valve which allows the
refrigerant to expand and cool the inside of the heat exchanger. The refrigerant flows
through the suction line to the compressor.
The refrigerant gives up its heat as it re-condenses to a liquid in the condenser and the cycle
starts over again.
SMC Series Chillers Page 17
Page 18
3-3 High Pressure Cutout
The high pressure cutout is an electro-mechanical safety feature that opens the control circuit if
the system condensing pressure exceeds a safe level. The chiller will automatically restart when
the pressure drops back to an acceptable level.
Model Cuts out if condensing pressure exceeds:
SMC050A 275 psi (1,897 kPa)
SMC100A 275 psi (1,897 kPa)
SMC150A 400 psi (2,759 kPa)
Important!
Call a refrigeration service technician to analyze
the problem if high pressure recurs.
3-4 Low Pressure Cutout
The low pressure cutout is an electro-mechanical safety feature that prevents compressor suction
pressure from dropping below a preset point.
It is factory set to open the control circuit when pressure drops below a safe level. The chiller
will automatically restart when the suction pressure reaches an acceptable level.
Model Cuts out if suction pressure falls below:
SMC050
A
SMC100
A
SMC150
A
15 psi (103 kPa)
15 psi (103 kPa)
35 psi (241 kPa)
3-5 Remote Start/Stop Interlock
A contact is provided to allow interlocking of the SMC Series Chiller with process controls. To
use this feature, remove the jumper between Terminals X1 and 1 on Terminal Block 1. Supply a
switch or dry contact interlock connected in series between these two terminals. See Figures 14
and 15 on Pages 32 and 33 for more information.
Page 18
SMC Series Chillers
Page 19
Figure 7
SMC Component Identification
SMC Series Chillers Page 19
Page 20
Discharge line
Figure 8
Piping Schematic — 1 Pump with Reservoir
Air-cooled condenser
Refrigeration
access valve
High
pressure
control
Compressor
Refrigeration
evacuation valve
Low
pressure
control
Refrigeration
access valve,
compressor-mounted
Suction
Line
Optional
CPR valve
Pump
Refrigeration
evacuation valve
Evaporator
Equalizing line
Power element
Temperature
probe
TC
S
Bypass
Expansion
valve
Optional
pressure
gauge
P
Tank
Relief
valve
Sight
glass
Filter
Vent
Liquid line
Filter
Drier
Fill
Sight
glass
Drain
Legend
Refrigeration lines
Chilled water piping
Condenser water piping
End of unit piping
To
Process
From
Process
Page 20
SMC Series Chillers
Page 21
Discharge line
Figure 9
Piping Schematic — 1 Pump without Reservoir
Air-cooled condenser
Refrigeration
access valve
High
pressure
control
Compressor
Refrigeration
evacuation valve
Low
pressure
control
Refrigeration
access valve,
compressor-mounted
Suction
line
Optional
CPR valve
Pump
Refrigeration
evacuation valve
Evaporator
Equalizing line
Power element
Temperature
probe
TC
S
Bypass
Expansion
valve
Optional
pressure
gauge
P
Relief
valve
Sight
glass
Filter
Liquid line
Filter
drier
Legend
Refrigeration lines
Chilled water piping
Condenser water piping
End of unit piping
To
Process
From
Process
SMC Series Chillers Page 21
Page 22
Figure 10
Piping Schematic — No Pump, No Reservoir
Refrigeration
access valve
High
pressure
control
Compressor
Discharge line
Refrigeration
evacuation valve
Refrigeration
access valve,
compressor-mounted
Suction
Low
pressure
control
line
Optional
CPR valve
Refrigeration
evacuation valve
Evaporator
Equalizing line
Power element
Temperature
Probe
TC
S
Bypass
Expansion
valve
Optional
pressure
P
Relief
valve
gauge
Filter
Sight
glass
Liquid line
Filter
drier
Air-cooled condenser
Legend
Refrigeration lines
Chilled water piping
Condenser water piping
End of unit piping
To
Process
Flow
switch
From
Process
Page 22
SMC Series Chillers
Page 23
4 Startup Checklists
4-1 Introduction
Follow the check lists below for the startup of your new chiller. These lists assume the
installation information elsewhere in this manual has been read and followed. New chillers
should be started up and checked by a qualified refrigeration service technician.
4-2 SMC Pre-Startup Checklist
1. Check the shipping papers against the serial tag to be sure chiller size, type and voltage is
correct for the process that will be controlled.
2. Check the transformer primary voltage connections to be sure they are configured for the
electrical power you are using. The voltage at the main power connection must read
within +/-10% of the voltage listed on the serial tag. Electrical connections must conform
to all applicable codes.
3. The chilled water TO PROCESS and FROM PROCESS connections should be completed.
4. Be sure the reservoir tank and chilled water circuit piping are filled with water.
5. The air-cooled condenser should have an adequate supply of air for proper operation.
6. Connect main power to the chiller and run the chiller just long enough to see if the pump
is generating normal pressure.
7. Check your work and proceed to the SMC Startup Checklist section below.
4-3 SMC Startup Checklist
1. Turn ON the chiller. The SMC chiller should continue to run until the switch is turned
OFF.
2. Put the SMC chiller under a process load.
3. Set the microprocessor control to the desired process temperature setpoint using the
, , and buttons. See Chapter 5 on Page 27 for more information.
4. Check the pump amp draw and pump pressure. The amp draw reading must be within the
running load and service factor amps.
5. Operate the chiller, looking for leaks and listening for unusual noises or vibrations that
could indicate improper operation.
SMC Series Chillers Page 23
Page 24
Figure 11
SMC Water Circuit Pressure Drop Table
Model Gallons per minute
2.0 2.5
SMC050A
SMC100A
SMC150A
2.4 4.0
3.6 7.5
4.8 12.5
2.0 2.5
2.4 2.5
3.6 3.0
4.8 5.0
2.0 2.5
2.4 2.5
3.6 3.0
4.8 3.5
∆P (psig)
Page 24
SMC Series Chillers
Page 25
5 Microprocessor Control
5-1 Introduction
Standard SMC Series chillers use a microprocessor based controller. The controller is a modular,
self-contained unit that can slide from its mounting housing. It is factory set and adjusted; no
field adjustment to the internal controls is necessary.
5-2 Setting the Process Water Temperature
• Press until the SP indicator lights.
• Press
temperature.
Note: SMC leaving water temperature range of operation is 30ºF (-1°C) to 65ºF (18°C).
• Press
or to raise or lower the setpoint to the desired leaving water
to display the current process temperature (SP and AL are off).
5-3 Setting the Alarm Value
• Press until AL lights.
• Press or to raise or lower the alarm value. The factory setting is 10, and
should be correct for most processes. Setting the alarm value to 10 creates an alarm if the
process temperature rises or falls 10ºF/ºC or more from the chiller process setpoint.
• Press
to display the current process temperature (SP and AL are off).
SMC Series Chillers Page 25
Page 26
Figure 12
SMC Control
Lights when the display
shows the alarm value
Lights if Process Temperature
is above the set point
Lights when Process Temp is
within +/- 1% of the full scale
Lights if Process Temperature
is below the set point
Lights when the display
shows the process set point
SP AL AL
OMRON E5CS
Scroll -- Steps Through Process
set point, actual temperature,
and alarm value displays
Compressor On indicator
ONC°
Process temperature is 10°
or more above the set point
Increases the process set point
or alarm value
Lowers the process set point
or alarm value
Page 26
SMC Series Chillers
Page 27
6 Optional Graphic Panel
6-1 Indicator Lights
PUMP ON (green)
This indicator is lit when the pump runs.
COMPRESSOR ON (green)
This indicator is lit when the compressor operates.
HIGH REFRIGERANT PRESSURE (red)
This indicator lights if the condensing pressure exceeds a safe level. The chiller goes to Idle
mode until the high refrigerant pressure cutout resets. The light then goes out and the chiller
automatically restarts. Call a qualified refrigeration service technician for service.
LOW REFRIGERANT PRESSURE (red)
This indicator lights if the refrigerant pressure drops below a safe level. The compressor will stop
and remain off until the pressure reaches a safe level. The light will go out and the chiller will
then resume operation automatically.
LOW WATER FLOW (red), SMC units without pump only
This indicator lights if the flow switch senses chilled water/glycol flow through the evaporator
dropping to an unacceptable level. The compressor will stop until the flow switch senses
adequate flow and restarts the chiller.
6-2 Switches
POWER
This switch energizes the control circuit; it also turns off the chiller.
SMC Series Chillers Page 27
Page 28
Figure 13
Optional Graphic Panel
SMC Series
ON
AL
O RO
E5CS
A0537868
ON
OFF
POWER
PUMP COMPRESSOR
ON
ON
Portable Chiller
LOW
REFRIGERANT
PRESSURE
HIGH
REFRIGERANT
PRESSURE
Page 28
SMC Series Chillers
Page 29
7 Routine Maintenance
7-1 Lubrication
Every three months, grease all fan motors and pump motors that do not have permanently sealed
bearings. Remove grease relief plug (motors only) before adding grease. Failure to do so may
result in dislodging the bearing grease retainer, eventually causing bearing failure.
Compressors are hermetically sealed; no oiling is required.
7-2 Condenser Maintenance
Dirty condenser heat exchange surfaces reduce system capacity.
Brush or vacuum light dirt accumulations. Avoid bending or damaging the fins. Heavy soil
accumulations on the coil require professional steam cleaning; washing from the outside only
makes matters worse.
Terminal
Blocks
Figure 14
Typical SMC Subpanel
Pump
Contactor
Distribution
Block
Condenser
Contactor
Grounding
Lug
Control Voltage
Transformer
SMC Series Chillers Page 29
Page 30
Figure 15
1C
Typical SMC Wiring Schematic
3
1
Earth
ground
Control
power
ON/OFF
1S-1LT
Remote
interlock
by others
Jumper
1L1
1L2
1L1
1L2
1L11L2
230V
1FU1FU
X111
1
115V
1T1T
2C
2
1C
G
G
1S-1LT
1T1
1T2
2T1
2T2
3T1
3T2
2
"Power On"
Pump
starter
1MTR
2MTR
3MTR
Pump
Compressor
Fan
Subpanel
ground
1CNTL
(+)
YEL
Type K Thermocouple
"Low Refrig
Pres"
R
G
1PS 2PS
41615
1
1
1
1
1
6
7
8
Jumper
11
2
3
1
1
(-)
RED
1
9
10
4
5
1
1
3LT
"Hi Refrig
Pres"
G
R
4LT
2LT
G
G
2C
5LT
G
G
Legend
Customer wiring/Customer-supplied components
Optional components
"Pump On"
Condensing unit
contactor
"Compressor On"
Page 30
SMC Series Chillers
Page 31
Figure 16
1C
SMC Wiring Schematic for Chillers with No Pump or Reservoir
3
1
Earth
ground
Control
power
ON/OFF
1S-1LT
1S
Remote
interlock
by others
Jumper
1FU
1FU
X111
"No Flow"
2LT
R
1FLS
1FLS
4 5
230V
115V
1L11L2
1T1T
"Low Refrig
Pres"
3LT
R
1PS1PS 2PS
5 76
1L1
1L2
2
"High Refrig
Pres"
R
4LT
1T1
1T2
2T1
2T2
1S-1LT
G "Power On"
G
1C
5LT
G
G
1MTR
2MTR
2
Condensing unit
contactor
"Compressor On"
2
Compressor
Fan
Subpanel
ground
6273849510
Jumper
1
(+)
YEL
Type K thermocouple
(-)
RED
1CNTL
Legend
Customer wiring/Customer-supplied components
Optional components
SMC Series Chillers Page 31
Page 32
- Notes -
Page 32
SMC Series Chillers
Page 33
8 Troubleshooting Guide
Problem Possible cause Solution
Check main disconnect
No power.
Wrong voltage supplied to
Chiller will not run.
Pump runs, compressor
cycles at short intervals.
The leaving water
temperature is too high.
Pump pressure is low (see
pump curves).
Pump pressure is too high. Restricted water flow.
the chiller.
Defective on/off switch. Replace.
Control circuit fuse blown.
Defective control transformer. Replace.
No process load on the
chiller.
Refrigerant is low. Check the refrigerant charge.
Refrigerant is low. Check the refrigerant charge.
Improper water/glycol
solution.
Check for foreign matter. Clean the system.
fuses, wiring, and power lead
to the unit.
Voltage must be within plus
or minus 10% of the
nameplate rating.
Replace, check the
transformer.
Increase the process load.
Make sure that the coolant
solution is right for the
process — must be 75%
water and 25% glycol.
See Figure 5 on Page 17 for
more information.
Check for partially closed
valves, etc. Be sure all lines
are properly sized.
SMC Series Chillers Page 33
Page 34
Problem Possible cause Solution
Pump runs, compressor will
not.
Unit runs continuously, but
not enough cooling power.
Refrigerant is low. Check the refrigerant charge.
Sight glass should be clear
Pressure switch contacts are
open.
while compressor runs. Call
for service if bubbling or
foaming.
Refrigerant high pressure
cutout switch contacts are
open.
Check for dirty condenser.
Check for condenser air
obstruction.
Defective fan motor. Repair or replace.
Check for high/low voltage.
Compressor internal overload
is open. Allow time to cool
and reset.
Must be within plus or minus
10% of the nameplate rating.
Check for poor compressor
electrical connections.
Broken wire in the
compressor control circuit.
Locate and repair.
Restricted condenser airflow. Clean the condenser.
Unit low on refrigerant. Call Service.
Inefficient compressor. Call Service.
Unit undersized for
application.
Call Sales Representative.
Page 34
SMC Series Chillers
Page 35
Figure 17
SMC Spare Parts List
Part number Description
A0537868 SMC graphic
A0537899 BZ pressure gauge
A0534584 Red neon graphic light *
A0534586 Green neon graphic light *
A0500857 2” swivel casters
A0534269 1/16 DIN digital temperature controller
A0537955 Process water flow switch
A0533873 Thermocouple, 8’
A0539409 150 VA transformer
A0103778 Rubber feet
A0537900 Tank sight glass assembly
A0537908 Handles
A0537915 SMC050A-SMC100A low refrigerant pressure switch
A0543063 SMC150A low refrigerant pressure switch
A0537916 SMC050A-SMC100A high refrigerant pressure switch
A0537917 SMC150A high refrigerant pressure switch
A0501642 SMC050A-SMC100A high refrigerant pressure safety relief valve
A0104093 SMC150A high refrigerant pressure safety relief valve
A0537974 Bronze Y strainer
* Units with the optional SMC graphic panel.
SMC Series Chillers Page 35
Page 36
Service Notes
Page 36
SMC Series Chillers
Page 37
Service Notes
SMC Series Chillers Page 37
Page 38
Parts Department
Call toll-free 7am–6pm CST [800] 783-7835 or call [414] 354-0970
The Sterling/Sterlco Parts Department at Sterling, Inc. is ready to provide the parts to keep your systems up and
running. Sterling/Sterlco replacement parts ensure operation at design specifications. Please have the model and
serial number of your equipment when you call. Consult the Customer Parts List included in your information packet
for replacement part numbers.
Service Department
Call toll-free 8am–5pm CST [800] 783-7835 or call [414] 354-0970
Emergencies after 5pm CST, call [847] 439-5655
Sterling/Sterlco has a qualified service department ready to help. Service contracts are available for most Sterling/
Sterlco products.
Sales Department
Call [414] 354-0970Monday–Friday, 8am–5pm CST
Sterling/Sterlco products are sold by a world-wide network of independent sales representatives. Contact our Sales
Department for the name of the sales representative nearest you.
Sterling
Page 38
Sterling/Sterlco
5200 West Clinton Avenue
Milwaukee, WI 53224-9518
[
414] 354-0970 • Fax [414] 354-6421
SMC Series Chillers
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