SterlingTEK A0551797 User Manual
$30.
00
Operation and Installation Manual
SSC Series
Central Chilling Stations
Important! Read Carefully Before Attempting to Install or Operate Equipment
Part No. A0551797 Revision: NEW Bulletin No. SC3-630
Write down your unit serial number(s) ________________ ________________
here for future reference ________________ ________________
________________ ________________
________________ ________________
Sterling 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 2006
All rights reserved. Effective 8/16/2006
Part No. A0551797 Revision NEW Bulletin No. SC3-630
Page 2 of 86 SSC Series Central Chilling Stations
Safety Considerations
Sterling central chilling stations 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:
þ Only PROPERLY TRAINED personnel familiar with the
information within this manual should work on this equipment.
þ Follow all local SAFETY CODES.
þ Wear SAFETY GLASSES and WORK GLOVES.
þ Disconnect and/or lock out power before servicing or
maintaining the chiller.
þ Use care when LOADING, UNLOADING, RIGGING, or
MOVING this equipment.
þ Operate this equipment within design specifications.
þ OPEN, TAG, and LOCK ALL DISCONNECTS before
working on equipment. Sterling recommends following OSHA
Lock-Out/Tag-Out Standard 29 CFR 1910.147.
þ Make sure the unit is properly GROUNDED before switching
power on.
þ 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.
þ Do not jump or bypass any electrical safety control.
þ Do not restore power until all tools, test equipment, etc. and
chiller and related equipment have been removed.
SSC Series Central Chilling Stations Page 3 of 86
Table of Contents
1 General Information.................................................7
1-1 Introduction......................................................................................7
1-2 Necessary Documents ....................................................................7
1-3 Models Covered..............................................................................8
1-4 Standard Features...........................................................................8
1-5 Available Options.............................................................................9
2 Shipping Information.............................................15
2-1 Unpacking and Inspection.............................................................15
2-2 In the Event of Shipping Damages................................................15
2-3 If the Shipment is Not Complete....................................................16
2-4 If the Shipment is Not Correct .......................................................16
2-5 Returns..........................................................................................16
2-6 Uncrating Your New Chiller...........................................................17
3 Installation..............................................................19
3-1 Installation Location Considerations..............................................19
3-2 Making Electrical Connections ......................................................19
3-3 Piping Considerations....................................................................21
3-4 Making Process Water Connections..............................................21
3-5 Making Tank Piping Connections..................................................22
3-6 Water Connection Sizing Considerations......................................23
3-7 Galvanic Corrosion Considerations...............................................23
3-8 Water Treatment Considerations...................................................23
3-9 Making Water-Cooled Condenser Connections ............................23
3-10 Installing the Remote Air-Cooled Condenser ................................24
3-11 Checking Motor Direction..............................................................25
4 Sequence Of Operation.........................................26
4-1 Staging..........................................................................................27
4-2 Alarms...........................................................................................27
4-3 Lead-Lag Compressors.................................................................27
4-4 Lead-Lag Pumps...........................................................................27
4-5 Chilled Water Circuit......................................................................28
4-6 Refrigeration Circuit.......................................................................28
4-7 Freezestat Control.........................................................................28
4-8 High Pressure Cutout....................................................................30
4-9 Low Pressure Cutout.....................................................................30
4-10 Flow Switch...................................................................................30
4-11 Control Nipple................................................................................31
4-12 Control Probe................................................................................31
4-13 Chilled Water Manifold ..................................................................31
4-14 Condenser Water Manifold............................................................31
Page 4 of 86 SSC Series Central Chilling Stations
Table of Contents
5 Startup Checklists .................................................33
5-1 Introduction....................................................................................33
5-2 Water-Cooled SSC Series Startup Checklist.................................33
5-3 Water-Cooled SSC Series Startup ................................................35
5-4 Remote Air-Cooled SSC Series Startup Checklist ........................35
5-5 Remote Air-Cooled SSC Series Startup........................................37
5-6 Determining Flow Rate..................................................................38
5-7 Shutdown ......................................................................................38
6 Graphic Panel Devices..........................................41
6-1 Indicator Lights and Control Switches (MMI).................................41
7 Using the Standard Touchscreen Interface.........43
7-1 Touchscreen Interface Introduction (MMI).....................................43
7-2 Using the SSC Series Standard Touchscreen Interface................44
7-3 Getting Started on the SSC Series Standard Touchscreen Interface45
7-4 Viewing and Operating Chiller Compressors.................................46
7-5 Viewing and Operating Chiller Pumps...........................................50
7-6 Viewing Active Alarms and Handling Alarm Conditions.................53
7-7 Viewing and Setting System Temperatures...................................55
8 Using the Advanced Touchscreen Interface....... 57
8-1 Touchscreen Interface Introduction (MMI).....................................57
8-2 Using the SSC Series Advanced Touchscreen Interface ..............58
8-3 Getting Started on the SSC Series Advanced Touchscreen
Interface..............................................................................59
8-4 Viewing and Operating Chiller Compressors.................................60
8-5 Viewing and Operating Chiller Pumps...........................................64
8-6 Viewing Active Alarms and Handling Alarm Conditions.................68
8-7 Viewing and Setting System Temperatures...................................71
9 Routine Maintenance.............................................73
9-1 Lubrication.....................................................................................73
9-2 Condenser Maintenance ...............................................................73
9-3 Evaporator Maintenance ...............................................................74
9-4 Pump Motor Seal...........................................................................74
9-5 Makeup Valve................................................................................74
9-6 Recommended Pump Tank Spare Parts.......................................74
9-7 Preventive Maintenance Service...................................................75
10 Troubleshooting .................................................... 77
I Index .......................................................................81
SSC Series Central Chilling Stations Page 5 of 86
Charts and Figures
1
Typical Two-Circuit 60-100 Ton Water Cooled Chiller 11
2
Typical Two-Circuit 60-100 Ton Remote Air Cooled Chiller 13
3
Freezing Protection Curve 29
4
SSC Series Standard Control Panel 39
5
SSC Series Advanced Control Panel 39
6
SSC Series Standard Control Panel 44
7
SSC Series Advanced Control Panel 58
8
Main Menu Screen (Advanced Control Panel) 59
9
10
11
12
13
14
15
16
17
Chiller Status Screen (Advanced Control Panel) 61
Chiller Configuration Screen (Advanced Control Panel) 62
Compressor Run Time Display Screen (Advanced Control Panel) 64
Pump Status Screen 65
Pump Enables Screen 66
Pump Run Time Display Screen 68
Alarm Condition Screen 69
System Status Screen 71
Temperature Input Display Screen 72
Page 6 of 86 SSC Series Central Chilling Stations
1 General Information
1-1 Introduction
Sterling SSC Series central water chilling stations are available in
water-cooled and remote air-cooled designs. They differ only in
the condensing media used. The SSC Series units are configured
with two independent circuits using multiple compressors for each
circuit. This manual lists information for these units.
SSC Series chilling stations may be configured with stainless steel
pump tanks for use as reservoirs for chilled water processes. These
dual-well models hold hot and cold water before and after it is
pumped through the chiller. Tanks have recirculation pump(s) to
send return water to the chiller and process pump(s) to pump
cooled water directly to process. Standby pumps may be utilized to
distribute pump service or to allow uninterrupted chiller operation
during pump maintenance.
Properly installed, operated, and maintained SSC Series chilling
stations 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 of Sterling SSC Series central
chillers. Additional copies are available from Sterling.
Familiarize the appropriate personnel with these documents:
þ This manual.
þ The schematic and connection diagram in the control
enclosure.
þ Operation and installation manuals for accessories and options
selected by the customer.
þ The Customer Parts List included in the information packet.
SSC Series Central Chilling Stations Page 7 of 86
1-3 Models Covered
This manual provides operation, installation, and maintenance
instructions for the SSC Series central chilling stations.
Model numbers are listed on the serial tag. A model number
followed by Q indicates a specially constructed unit, and not all
information in this manual may apply. Make sure that you know
the model number, serial number, and operating voltage of your
chiller if you contact Sterling.
1-4 Standard Features
• Two independent refrigeration circuits
• High-efficiency scroll compressors
• Stainless steel brazed plate evaporators
• Cleanable shell and tube condensers (water-cooled models)
• Two-way water regulating valve (water-cooled models)
• 2 remote single circuit condensers with variable speed lead
fans and fan cycling (air-cooled models)
• NEMA 12 electrical enclosure
• Allen Bradley Micrologix 1500 PLC control with PanelView
300 Micro monochrome/key pad interface
• High and low refrigerant pressure safeties
• Touch-safe branch circuit fusing
• Evaporator water piping manifold (Condenser manifold
optional)
• HCFC-22 refrigerant
• Digital low temperature freezestat
• Liquid line solenoid and shut-off valves
• Chilled water flow switches
• Auto/Manual control mode switch for emergency operation
• 1 year warranty on parts and labor
• 3 year warranty on controller
Page 8 of 86 SSC Series Central Chilling Stations
1-5 Available Options
SSC Series central chillers are available with options to tailor the
unit to your requirements. Some are factory installed; some can be
retro-fitted in the field. Consult Sterling sales for more
information. Available SSC Series options include:
• Advanced control package including: AB SLC 5/04 PLC with
PanelView 1000 color touch screen, control of up to nine
additional chillers, cooling tower system, water treatment
system, and DH+ communication capabilities
• General Fault audible/visual alarm with elevated light stack
• Non-fused rotary thru-the-door disconnect switches
• Electrical operation available in 208, 460, and 575 volts, 60
Hz; 200, 380, and 415 volts, 50 Hz
• UL/CUL-listed electrical subpanel
• Water cooled condenser manifold
• Onsite startup
Standard Features on Remote Condensers
• Direct-drive 3-phase fan motors with ball bearings and internal
overload protection
• Electronic variable-speed control of lead fan and fan cycling
for constant condenser head pressure control
• Fans are 30” (76 cm) in diameter and have PVC-coated steel
fan guards; 1½ hp (1.12 kW) variable-speed fans are 26” (66
cm) in diameter
• Internal baffles between fan cells
• UL listed in the United States and Canada
• Patented floating tube coil to eliminate tube sheet leaks
• Copper tube condenser coils have corrugated aluminum fins
• Weather-proof control panel with factory-mounted door
interrupt switch
• High-efficiency condenser coil, designed for optimum
performance
• Aluminum housing provides corrosion protection for outdoor
applications
SSC Series Central Chilling Stations Page 9 of 86
Model Number Nomeclature
SSC W 060
SSC – Scroll Compressor Central Chiller
Condenser Type
R – Remote Air Cooled
W – Water Cooled
Nominal Unit Size – Tons (kW)
030 – 30 (105.4) 070 – 70 (246.0)
040 – 40 (140.6) 080 – 80 (281.2)
050 – 50 (175.7) 090 – 90 (316.3)
060 – 60 (210.9) 100 – 100 (351.5)
Page 10 of 86 SSC Series Central Chilling Stations
Figure 1
Typical Two-Circuit 60-100 Ton Water Cooled Chiller
Model
Cooling Capacity (tons) @ 50°F (10°C) LWT • 32.4 41.4 50.2 64.8
Capacity stages (qty.) 2 4
EER (BTUH/W) 15.65 14.91 15.35 15.66
Evaporator ‚ 78 [295.3] 99 [374.8] 120 [454.2] 156 [590.5] Nominal water flow (gpm)
[lpm]
Condenser connection (no manifold) Flange Conn. (in.) (2) 2 (2) 2 (2) 2 (2) 2 1/2
Evaporator manifold connection Victaulic 3 3 3 3
Amp draw, nameplate (460/3/60 V) „ 56 70 88 111
Dimensions (in.)[cm]
Shipping weight (lbs)[kg] 1,520
Max operating weight (lbs.)[kg] 1,610
Condensers ƒ 97 [367.2] 124 [469.4] 151 [571.6] 194 [734.4]
Height 85 [215.9]
Width 66 [167.6] 94 [238.8]
Depth 45 [114.3]
30 40 50 60
[689.5]
[730.3]
SSCW-xxx
1,900
[861.8]
2,010
[911.7]
2,120
[961.6]
2,260
[1025.1]
2,700
[1224.7]
2,870
[1301.8]
SSC Series Central Chilling Stations Page 11 of 86
Model
70 80 90 100
SSCW-xxx
Cooling Capacity (tons) @ 50°F (10 °C) LWT • 73.1 81.4 90.3 99.2
Capacity stages (qty.) 4
EER (BTUH/W) 15.15 14.63 14.90 15.16
Nominal water flow (gpm)
[lpm]
Evaporator ‚ 175 [662.4] 196 [741.9] 217 [821.4] 238 [900.9]
Condensers ƒ 219
[829.0]
244
[923.6]
271
[1025.8]
298
[1128.1]
Condenser connection (no manifold) Flange Conn. (in.) (2) 2 1/2 (2) 2 1/2 2 1/2 / 3 (2) 3
Evaporator manifold connection Victaulic 3 3 4 4
Amp draw, nameplate (460/3/60 V) „ 124 138 156 174
Height 75 [190.5]
Dimensions (in.)[cm]
Width 94 [238.8] 115 [292.1]
Depth 45 [114.3]
Shipping weight (lbs)[kg] 3,000
[1360.8]
Max operating weight (lbs.)[kg] 3,200
• Based on 50ºF (10ºC) chilled water supply temperature and 85ºF (29ºC) tower water.
‚ Based on 2.4 gpm per ton (9.1 lpm per 3.517 kW).
ƒ Based on availability of 85ºF (29ºC) tower water at 25 psi (172.4 kPa/1.7 bars) minimum.
„ Multiply 460/3/60 amperage by 2.0 for 208-230/3/60 amperages; multiply by 1.2 for 380/3/60 amperages; multiply by 0.8 for
575/3/60 amperages
[1541.5]
3,300
[1496.9]
3,520
[1596.6]
3,580
[1623.9]
3,830
[1737.3]
3,880
[1759.9]
4,160
[1886.9]
Page 12 of 86 SSC Series Central Chilling Stations
Figure 2
Typical Two-Circuit 60-100 Ton Remote Air Cooled Chiller
Model
Cooling Capacity (tons) @ 50°F LWT • 29.8 38.4 46.2 59.6
Capacity stages (qty.) 2 4
EER (BTUH/W) 11.36 10.84 11.29 11.11
Nominal water flow (gpm)
[lpm]
Evaporator manifold connection Victaulic 3 3 3 3
No. of condenser fans per condenser 3 2 2 3
Amp draw, nameplate
(460/3/60 V) ƒ
Dimensions (in.) [cm] of
chiller
Dimensions (in.) [cm] of
each condenser
Shipping weight (lbs) [kg]
Max operating weight
(lbs.) [kg]
Model
Cooling Capacity (tons) @ 50°F LWT • 67.5 75.4 83.5 91.6
Capacity stages (qty.) 4
EER (BTUH/W) 10.84 10.64 10.93 11.19
Nominal water flow (gpm)
[lpm]
Evaporator manifold connection Victaulic 3 3 4 4
No. of condenser fans per condenser 3/4 4 4 4
Amp draw, nameplate
(460/3/60 V) ƒ
Dimensions (in.) [cm] of
chiller
Dimensions (in.) [cm]of
each condenser
Shipping weight (lbs) [kg]
Max operating weight
(lbs.) [kg]
• Based on 50ºF (10ºC) chilled water supply temperature and 95ºF (35ºC) ambient air.
‚ Based on 2.4 gpm per ton (9.1 lpm per 3.517 kW)
ƒ Multiply 460/3/60 amperage by 2.0 for 208-230/3/60 amperages; multiply by 1.2 for 380/3/60 amperages; multiply by 0.8 for
575/3/60 amperages
Evaporator ‚
Chiller 56 70 88 111
Condensers (per
condenser)
Height 85 [215.9]
Width 60 [152.4] 83 [210.8]
Depth 45 [114.3]
Height 50 [127.0]
Width 42.5 [108.0]
Depth 130 [330.2] 125 [317.5] 125 [317.5] 180 [457.2]
Chiller 1,340
Condensers (per
condenser)
Chiller 1,350
Condensers (per
condenser)
Evaporator ‚
Chiller 124 138 156 174
Condensers (per
condenser)
Height 75 [190.5]
Width 86 [218.4]
Depth 45 [114.3]
Height 50 [127.0]
Width 42.5 [108.0]
Depth 180 [457.2] 235 [596.9]
Chiller
Condensers (per
condenser)
Chiller
Condensers (per
condenser)
30 40 50 60
72
[272.5]
3.9 7 7 10.5
[607.8]
550
[249.5]
[612.3]
610
[276.6]
70 80 90 100
162
[613.2]
10.5/14 14 14 14
2,360
[1070.5]
1190/1580
[539.8/716.7]
2,400
[1088.6]
1420/1805
[644.1/818.7]
SSCR-xxx
92
[348.3]
1,530
[694.0]
770
[349.3]
1,550
[703.1]
845
[383.3]
SSCR-xxx
181
[685.2]
2,600
[1179.3]
1580
[716.7]
2,640
[1197.5]
1805
[818.7]
111
[420.2]
1,730
[784.7]
790
[358.3]
1,760
[798.3]
945
[428.6]
200
[757.1]
2,870
[1301.8]
1580/1650
[716.7/748.4]
2,910
[1320.0]
1805/1895
[818.7/859.6]
143
[541.3]
2,120
[961.6]
1190
[539.8]
2,150
[975.2]
1420
[644.1]
220
[832.8]
3,170
[1437.9]
1650
[748.4]
3,220
[1460.6]
1895
[859.6]
SSC Series Central Chilling Stations Page 13 of 86
SSCR Series Remote Condenser Models
Fan(s) Refrigeration ‚
Each Connections Charge
Model Dia. Motor Amps Air flow Discharge Liquid R-22
Number in. hp • 460V Fans cfm ƒ ODS(in.) ODS(in.) lbs. ƒ
SSCR30 26 ¾ hp 3 ø 3.9 3 20,500 15/8 11/8
SSCR40 30 1 ½ hp 3 ø 7.0 2 23,200 15/8 15/8 12
SSCR50 30 1 ½ hp 3 ø 7.0 2 21,900 15/8 15/8 12
SSCR60 30 1 ½ hp 3 ø 10.5 3 34,800 21/8 21/8 19
SSCR70 a 30 1 ½ hp 3 ø 10.5 3 34,800 21/8 21/8 19
b 30 1 ½ hp 3 ø 14.0 4 46,400 21/8 21/8 22
SSCR80 30 1 ½ hp 3 ø 14.0 4 46,400 21/8 21/8 22
SSCR90 a 30 1 ½ hp 3 ø 14.0 4 46,400 21/8 21/8 22
b 30 1 ½ hp 3 ø 14.0 4 42,400 21/8 21/8 27
SSCR100 30 1 ½ hp 3 ø 14.0 4 42,400 21/8 21/8 27
• ø represents electrical phase; all motors are 1,140 rpm. Multiply hp by 0.746 to convert to kW.
‚ Refrigeration charge is for remote condenser only!
ƒ To convert cfm to cmh, multiply by 1.699. To convert lbs. to Kg, multiply by 0.454.
Page 14 of 86 SSC Series Central Chilling Stations
2 Shipping Information
2-1 Unpacking and Inspection
You should inspect your central chilling station for possible
shipping damage. If the container and packing materials are in reusable condition, save them for reshipment if necessary.
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 case of
breakage, damage, shortage, or incorrect shipment, refer to the
following sections.
2-2 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.
þ Notify the transportation company’s local agent if you discover
damage.
þ Hold the damaged goods and packing material for the
examining agent’s inspection. Do not return any goods to
Sterling before the transportation company inspection and
authorization.
þ 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, contact Sterling at (414) 354-0970 for a receipted
transportation bill.
þ Advise Sterling regarding your request for replacement
and to obtain an RMA (return material authorization)
number.
SSC Series Central Chilling Stations Page 15 of 86
2-3 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:
þ Sterling SSC Series central chilling station
þ Bill of lading
þ Packing list
þ Operating and Installation packet
þ Electrical schematic and panel layout drawings
þ Component instruction manuals
þ Parts list
Re-inspect the container and packing material to see if you missed
any smaller items during unpacking. Determine that the item was
not inadvertently taken from the area before you checked in the
shipment. Notify Sterling immediately of the shortage.
2-4 If the Shipment is Not Correct
2-5 Returns
Do not return any damaged or incorrect items
until you receive shipping instructions from Sterling.
If the shipment is not what you ordered, contact Sterling
immediately. Include the order number and item. Hold the items
until you receive shipping instructions.
Important!
Page 16 of 86 SSC Series Central Chilling Stations
2-6 Uncrating Your New Chiller
! WARNING !
DUE TO THE SIZE AND WEIGHT OF SSC SERIES CHILLERS,
STERLING RECOMMENDS USING BONDED PROFESSIONAL
MILLWRIGHTS TO UNLOAD AND MOVE SSC SERIES CHILLERS.
Rig the chiller from the frame only, using spreader bars to prevent
load transfer to any chiller components. Rig the frame from at least
four points and balance the load before lifting to clear the skid. Use
a forklift of adequate size when lifting the chiller by the fork
pockets.
Insert the forks all the way into the pockets and be sure to balance
the load before lifting the chiller to clear the skid. Lift only as high
as necessary. Use a pry bar to free the skid if necessary. Lower
slowly. Retain the crating in case reshipment is necessary due to
hidden shipping damage.
Caution!
Due to the weight of these units, use extreme caution
when moving and placing SSC Series chillers.
.
SSC Series Central Chilling Stations Page 17 of 86
- Notes -
Page 18 of 86 SSC Series Central Chilling Stations
3 Installation
3-1 Installation Location Considerations
As with all equipment installations, follow all applicable codes and
regulations.
þ Locate close to the process to reduce piping expense.
þ Locate adjacent to drain and city water sources.
þ Consult a structural engineer to assure that the floor, mounting
pad or structural steel support is of adequate strength.
þ Allow for required service clearances necessary for condenser
maintenance and easy access to all components.
3-2 Making Electrical Connections
SSC Series systems are designed for three-phase voltage operation.
Refer to the unit nameplate for proper voltage and amperage
requirements.
Make sure you provide a correctly sized and protected supply of
electrical power to the unit.
Important!
Refer to National Electric Code (NEC) Article 430-24 through 430-26
for proper feeder conductor and supply disconnect sizing.
Maintain a safe ground and disconnect the power supply before
servicing the unit. A qualified electrician should make electrical
connections, and disconnect and lock out electricity using OSHA
29CFR 1910.147 standards when you need a service call.
Check serial tag voltage and amperage requirements and make sure
your electrical service conforms before making any electrical
connections. Total running amps for the SSC Series systems are
listed on the nameplate. Customer connections can be run to the
supply terminals from either side of the unit. Make sure that all
three phases are wired correctly. If not wired properly, the unit will
run backwards. Again, check the unit nameplate for correct
voltage and amperage.
SSC Series Central Chilling Stations Page 19 of 86
! DANGER
Improper electrical connections
can damage the unit and cause
serious operator injury or death!
Bring properly sized power leads and ground from a fused
disconnect (installed by your electrician) to the unit. Provide
external overcurrent protection to the unit, using circuit breakers or
fuses. If you use fuses, make sure that they are dual-element timedelay fuses, sized according to your electrical code. Make sure that
all electrical connections are tight.
Important!
1. Electrical connections must comply with all applicable electrical codes.
2. The chiller must be grounded in accordance with NEC Article 250.
3. Voltage must be within plus or minus ten percent (±10%) of the nameplate
rating.
4. Make sure your installer provides external protection.
Check the electrical wiring schematic
provided in your Customer Information packet
for additional information.
Page 20 of 86 SSC Series Central Chilling Stations
• Never switch contactor leads or motor leads for reversing
rotation.
• Do not use contactor or motor leads for phase matching.
• Compressor noise from reverse rotation is noticeable. Do not
run in this mode for more than ten (10) seconds. The
compressor shuts off if it is run longer in this mode.
• Reverse rotation can cause suction and discharge pressures to
be approximately equal; amp draws will be lower than normal.
• If you discover that compressor rotation is reversed, correct it
by switching any two main power leads into the disconnect
switch or distribution block on the unit.
Note:
Check your work and proceed to the following Piping Considerations section.
3-3 Piping Considerations
Piping systems vary with process application and pump tank
configuration. Typical system configuration drawings are provided
in this manual; the details may or may not apply to your
application. Piping systems must be designed by a person
knowledgeable in piping system design and configuration.
Sterling’s Contracting Department can design and install a piping
system tailored to your process.
• All piping returning to the pump tank must be equipped with
an inverted trap with a vacuum breaker at the high point of the
system to prevent mains from siphoning into the pump tank.
• Run mains full size in order to reduce pressure drop in the
system and provide maximum pressures at the ends of the
mains.
3-4 Making Process Water Connections
All Models
All SSC Series chilling stations have two chilled water connections
per unit, and on water-cooled models, one more set of water
connections for condenser water:
SSC Series Central Chilling Stations Page 21 of 86
To Process
The chilled water supply outlet leading to the process being
controlled.
From Process
The chilled water return for water returning back to the chiller
from the process to be cooled and recirculated.
3-5 Making Tank Piping Connections
If you have purchased the SSC Series central chilling station with
the integral pump tank, please proceed with this section.
Return
Bring the chilled water returning from the process to the pump
tank warm From Process side. This line is sized according to the
flow rate from the process to the pump tank. See Section 3-3 on
Page 21 for more information on piping considerations.
Important!
Makeup
Overflow
To Drain
Do not use the SSC Series unit to support piping.
Connect a city water source to maintain water level in the pump
tank.
Connect the OVERFLOW outlet to an approved, trapped drain to
permit excess water in the pump tank to overflow to the drain. The
overflow line is sized according to the size of the pump tank.
Connect to a 1½” line (approx. 63 mm) leading to an approved,
trapped drain. You can drain the pump tank if necessary.
Page 22 of 86 SSC Series Central Chilling Stations
3-6 Water Connection Sizing Considerations
Important!
• Run all external chilled water connections with adequate size to the
process.
• Provide the largest possible openings and passages for the flow of chilled
water through platens, dies, molds, or other pieces of equipment.
• Minimum external pressure drop is critical for proper operation.
3-7 Galvanic Corrosion Considerations
Water circuit piping components are primarily ferrous (iron) and
react electro-chemically with non-ferrous metallic materials such
as copper. Some water has dissolved minerals that will greatly
accelerate the reaction between dissimilar metals.
Use PVC or ferrous piping to minimize galvanic action. If piping
must be copper, use dielectric unions at the chiller.
3-8 Water Treatment Considerations
Water treatment is important in any piping system. In some
locations, raw water may be used in the system without problem;
in other locations, it will result in large deposits of scale and
corrosion.
Sterling offers a complete line of water treatment equipment.
Contact your Sterling sales representative for water testing and
treatment options.
3-9 Making Water-Cooled Condenser Connections
SSC Series water-cooled chilling stations use city or tower water
as a cooling medium. All external condenser supply and discharge
piping and connections should be of adequate size.
SSC Series Central Chilling Stations Page 23 of 86
Condenser Water In
Condenser Water Out
Two connections are made to each SSC Series unit:
The city or tower water supply inlet is located at the side or rear of
the chiller.
• Water pressure ≥25 psi (≥172.4 kPa/≥1.72 bars)
• Water temperature ≤85°F (≤29ºC)
The return outlet, located at the chiller side or rear is connected to
a cooling tower inlet, a sewer or other approved discharge receiver.
• A water regulating valve is a standard feature in the condenser
water out line.
Caution!
The water regulating valve is set at the factory.
It must not be adjusted except by a qualified refrigeration technician.
3-10 Installing the Remote Air-Cooled Condenser
SSC Series models use the surrounding air to cool the remote
condenser. All models have variable speed fans and low ambient
controls to allow proper operation down to -20°F (-29ºC) outdoor
air temperature.
Install the remote air cooled condenser where there is:
• Greater than or equal to -20°F (-29ºC) air temperature.
• Free passage of air for condensing.
• Adequate structural support.
• Protection from strong winds and drifting snow.
• Provisions for removal of heated air from the area.
• No steam, hot air or fume exhausts drawn into the condenser
coils.
• Service accessibility.
Page 24 of 86 SSC Series Central Chilling Stations
SSC Series condensing pressure
with 95ºF (35ºC) condenser air
R-22 = 260 psi (1,793 kPa/17.93 bars)
Note: Due to the variables involved in remote air-cooled condenser installations, no set or
standard piping procedure exists. Each installation must be designed and installed by
qualified persons. Follow the instructions supplied with the condenser.
3-11 Checking Motor Direction
Compressor
Note:
• Never switch contactor leads or motor leads for reversing
rotation.
• Do not use contactor or motor leads for phase matching.
• Compressor noise from reverse rotation is noticeable. Do not
run in this mode for more than ten (10) seconds. The
compressor shuts off if run longer in this mode.
Water Pump
Condenser Fan
• Reverse rotation can cause suction and discharge pressures to
be approximately equal; amp draws will be lower than normal.
• If you discover that compressor rotation is reversed, correct it
by switching any two main power leads into the disconnect
switch or distribution block on the unit.
A positive pressure of 20 to 30 psi (137.9 to 206.8 kPa/1.38 to 2.07
bars) on the TO PROCESS line indicates correct pump rotation.
On SSC Series remote air-cooled units, air should draw through
the condenser and discharge up from the condenser.
Changing fan rotation direction
• Disconnect and lock out power at the fused disconnect.
• If all fans are going backwards, reverse any two main power
leads.
• If only some of the fans are going backwards, switch any two of
their respective motor leads.
SSC Series Central Chilling Stations Page 25 of 86
-Notes-
Page 26 of 86 SSC Series Central Chilling Stations
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