Multistack MS010XC Owner's manual

Modular Water-Cooled
Chillers
Installation, Operation,
Maintenance
MS010XC, MS015XC, MS020XC, MS030XC,
MS040XC, MS050XC, MS070XC, MS085XC
Standard and Total Access™ Modules

2
Contents
Safety Information.....................................................................................................................................................................................3
Nameplate and Model Number Nomenclature..............................................................................................................................4
Chiller Arrangement and Components, Standard and Total Access™ Modules...............................................................5-7
General Data................................................................................................................................................................................................8
Shipping Information..........................................................................................................................................................................9-10
Clearances and Dimensions............................................................................................................................................................11-16
Piping, Flow Protection...........................................................................................................................................................................17
Pressure Relief Piping, Water Treatment Specications, Pipe Flushing.................................................................................18
Module Assembly, Standard Modules........................................................................................................................................19-21
Module Assembly, Total Access™ Modules......................................................................................................................................22
Multiush Assembly, Leak Testing......................................................................................................................................................23
Electrical Installation, Wiring, Electrical Data............................................................................................................................24-28
Frame and Enclosure Panel Installation............................................................................................................................................29
Installation Checklist................................................................................................................................................................................30
Start-Up Data Log...............................................................................................................................................................................31-32
Operation...............................................................................................................................................................................................33-34
Maintenance.........................................................................................................................................................................................34-36
Troubleshooting....................................................................................................................................................................................... 37
Daily Log................................................................................................................................................................................................38-39
This Multistack installation and operation manual will assist in the proper installation and operation of Multistack modular chillers. Review this
manual carefully.
• The information and illustrations contained in this manual are generalized. Consult with a Multistack representative to address specic
installation and operating details not covered in this manual.
• Good electrical and piping practices in accordance with all National and local codes must be followed.
• This equipment must not be installed near an open ame per local codes and ASHRAE specications.
• Personnel servicing Multistack modular chillers must have, at minimum, a Class II EPA certication.
• Questions regarding the content of this manual and Multistack products should be directed to an authorized Multistack representative or
to the Multistack Service Department at: [phone] or via e-mail to [email protected]
Planning Ahead
To ensure all warranties and a successful installation, a Factory AuthorizedTechnician is required to perform start-up of the Multistack Chiller. If start-up
is to be performed directly by Multistack, a minimum of two weeks notice is required. Please call the Multistack Service Department at [phone] to
schedule.
Multistack has a policy of continual improvement and reserves the right to change product design, literature and
specications without notice.
© 2016 Multistack
This manual provides information on the proper installation, operation and maintenance requirements for Multistack water-
cooled modular chillers. Follow these instructions to help ensure that the chiller performs properly. Failure to follow these in-
structions can signicantly aect the chiller’s performance and reliability and may adversely aect the equipment warranty.

3
Safety Information
This manual includes warnings, cautions and notes.
DANGER conveys serious hazards for injury or death.
WARNING indicates risk of injury or death.
CAUTION warns of possible injury or damage.
NOTE calls out work practices that can result in optimal operations.
Warnings, cautions and notes include:
DANGER:To avoid the risk of electrical shock, personal injury or death, disconnect all electrical power to the unit before performing any maintenance
or service.The unit may have more than one electrical power supply. Assume all electrical wires are live, energized wires. Use lockout/tag outs.
DANGER: Use extreme caution when working around electrical components, wiring and connections to avoid injury or death by electric shock.
DANGER: Never remove a lockout from equipment unless you placed it there. Each person shall place his/her own lock/tag when required to isolate
an energy source. Do not start any adjustment, service or repair without verifying that the tag/lock out switch or control cannot be by-passed or over-
ridden. Verify that the locked-out switch or control cannot be overridden.Test the equipment to be certain that the locked-out switch is de-energized
and not simply malfunctioning. Press all start buttons to conrm that the equipmentWILL NOT start. Conrm that the system being serviced or
repaired is the system that has been locked out. Before restarting equipment, verify all tools and other items have been removed, all machine guards
are in place, all electric systems are reconnected, and personnel are clear of equipment.
DANGER: During installation, testing, servicing and troubleshooting this product, it may be necessary to work with live electrical components. Only
qualied licensed electricians or other properly trained persons may perform these tasks. Failure to follow all electrical safety precautions can result in
death or serious injury. All HVAC equipment must be installed per the National Electric Code (NEC) and/or all applicable state/local codes.
DANGER: Incorrect handling of HVAC equipment can result in explosions, electrical shock or re, causing property damage, injury and/or fatality.
DANGER: HVAC liquids and chemicals can be dangerous if used incorrectly or if spills or accidents occur. Handle detergents and solvents with care to
avoid spills and burns.
DANGER: Danger of explosion. Refrigerant cylinders can explode causing serious injury and/or death if not handled and stored properly.
WARNING: Only qualied, licensed electricians with proper personal protection equipment should wire Multistack chillers. Injury or death my result
if not properly wired due to electric shock hazard
WARNING: Danger of electrical shock. Many types of HVAC equipment have switches and regulators with electrical current on even when other parts
of the equipment appear to be turned o. Main circuit breakers must be turned o before servicing equipment to avoid injury, fatality.
WARNING: Be sure to use lifting slings with lifting capacity to safely handle unit weight. Consult the unit’s as-built submittal drawings for unit
weight data.
WARNING: If welding on chiller water connections, use proper electrical grounding to avoid damaging the compressors or chiller controls. Never
weld directly on the heat exchanger shells. Only an authorized ASME-certied repair agency may weld directly on ASME-certied shells. After weld-
ing, an“R”stamp is required.
CAUTION: Working with HVAC equipment can be hazardous due to electricity, moving parts, chemicals, combustion and other hazards. Use safe work
habits including proper tools and personal protective equipment. Understand and heed all safety information, installation guidelines and operation
and maintenance procedures.
CAUTION: Pressurized application of cleaning substances or refrigerants must be done with the correct procedures to ensure the safety of technicians
and others, and avoid property damage.
NOTE: Use correct tools for HVAC equipment installation, maintenance and adjustment. Use the correct tools to make tight connections without strip-
ping threads or breaking screws and bolts. Use accurate refrigerant and electrical meters to properly maintain and diagnose HVAC equipment.

4
MS 050 X C or N 2 H 1 W 0 A A -410A
Series
Module Nominal Capacity (10 - 160 tons)
Compressor Type1
AHRI Certied (C - certied, N - Not certied)
Conguration2
Voltage3
Module Number ( 1 - single, 2 - multiple)
Application4
AHRI Version - if applicable
Evaporator5
Condenser6
Refrigerant
1B: Bristol, C:Trane Cornerstone, R: Bitzer Screw, S: Trane Scroll,T: DanfossTurbocor, Z: Copeland scroll (old elec), X: Copeland Scroll (ZP), A: Copeland Scroll (ZR)
21- Standard, 2- Total Access, 3 - Evap extended headers, 4 - Cond extended headers, 5 - Both extended headers, V - others
3A - 208/3/60, L - 230/3/60, H - 460/3/60, C - 575/3/60, D - 200/3/50, E - 400/3/50, F - 380/3/60, S - 220/230/1/60, V - other
4A - Air Cooled split, C - Single module temp controller, D - Cond unit, F - Fluid cooler (high temp),H - Heat recovery, R - Heat pump, W -Water cooled
5A - Brazed SS, B - Brazed SMO, C- S&T copper, D - S&T cu-Ni, V - Other
6A - Brazed SS, B - Brazed SMO, C- S&T copper, D - S&T cu-Ni, E - Double wall brazed, V - Other
Model Number Nomenclature
Unit Nameplate
The chiller nameplate is located on the front of the control panel.
Use the unit model number nomenclature to identify specic
features and options of an Multistack chiller module.
Multistack Water-Cooled Modular Chillers
Multistack invented the modular chiller. Multistack modular
chillers are available in a wide range of capacities, and with two
independent scroll compressors. Modules can be mix-matched
and combined to create up to 15-module arrays and 1,275 tons of
cooling capacity using environmentally friendly R-410A. Multistack
modular chillers can help owners qualify for USGBC LEED points and
signicant utility rebates. Multistack’s innovative modular design
makes adding more capacity as easy as purchasing and installing
more modules.
Total Access™ Modular Chillers
With Total Access, heat exchangers are located on the outer edges of
the chiller frame to provide easy serviceability with a small equip-
ment room footprint. Total Access options include 10- through 85-ton
modular chillers.

5
Unit
Nameplate
High Pressure
Transducer
High Voltage
Panel
Isolation/Disconnect
Switch
Buss Bar
Duct
Entering Chilled
Water Header
Leaving Chilled
Water Header
Evaporator
Filter/Strainers
Leaving
Condenser
Water
Header
Entering
Condenser
Water
Header
Scroll Compressors
Condenser Expansion
Valve
Liquid Line
Sight Glass
Low Pressure
Transducer
Low Voltage
Panel
Standard Modular Chiller Arrangement
Total Access™ Modular Chiller Arrangement
Multistack’s Total Access option makes maintenance and serviceability even easier by placing heat
exchangers at the outside of the module frame. Manual isolation valves are factoryinstalled (Total
Access units only) between the heat exchangers and water supply mains for heat exchanger isolation and
removal without the need to remove a module or shut down the entire chiller while allowing access to all
serviceable components.
High Voltage
Panel
High Pressure
Transducer
Evaporator
Expansion
Valve
Low Voltage
Panel Isolation/Disconnect
Switch
Buss Bar
Duct
Condenser
Filter/Strainers
Scroll Compressors
Low Pressure
Transducer
Isolation
Valve
Condenser

6
Chiller Components
Master Control Panel
Each chiller has a master control panel that can be mounted on top of any
of the module panels using provided knockouts. Sensors, cables and wiring
connect through the bottom of the master control. The master control box
includes built-in terminal strip inputs for ow switches, start/stop signal, alarm
output, and power phase monitor. As shipped, the Master Control also contains
the pLAN communication wire to be eld installed by the start-up technician.
Four temperature sensors and sensor wells are supplied by Multistack: entering
chilled water, leaving chilled water, entering condenser water, and leaving
condenser water. The sensors are to be installed in customer’s piping system.
Module Control Boards and Low Voltage Panel
The module control boards communicate individual module temperatures
and pressures to the master control. Each module has a switch labeled Auto/
O/ Manual. Normal operation is in the Auto mode. If there is a problem with
the master control, the selector switch can be changed to Manual to provide
individual module leaving chilled water temperature control that was pre-set
at the master control.
Module High Voltage Panel
The high voltage panel contains each compressor’s contactor, circuit breaker,
control relay and transformer. External to the panel is the single-module isola-
tion switch to isolate the that module from high voltage supply power.
Compressors, Sensors, Switches
• Standard modules use two scroll compressors with separate refrigeration
circuits.
• Each refrigerant circuit has a high pressure (HP) and low pressure (LP)
transducer that sends pressure signals to the module slave controller
board. Each compressor also includes an HP switch with a manual reset
button.
• Transducers are a 0-5V ratiometric type.
• Compressors include oil level sight glasses. Oil level should be at ⁄ - ¼
full during operation.
• Each circuit has its own leaving chilled water temperature sensor and
refrigerant suction temperature sensor.
• Compressor crankcase heaters are not standard on Multistack MS chiller
modules.
Chilled and Condenser Water Connections
• Water connections to the chilled and condenser side are standard 6-inch
grooved pipes on MS010X through 070X, and 8-inch on MS085X units.
• The upper header on the chilled water side is entering water to the
module.
• The bottom header is chilled water leaving the module.
• Water entering the condenser is on the bottom.
• Water leaving the condenser is on top.
• The entering header on both the evaporator and condenser contains a 30-
mesh lter strainer to prevent debris from entering the brazed plate heat
exchangers. This strainer should only be used as a nal lter stage.
• Proper ltration before the module should be installed for easy access to
cleaning, such as a‘Y’or a basket type of strainer.
High Voltage Panel
A Compressor
Isolation Switch
Control
Relay Transformer
High Voltage
Circuit Breaker Control
Relay
B Compressor
Isolation
Switch
A Compressor
Contactor
B Compressor
Contactor
Single
Circuit
Breaker
Master Controller
AUTO/OFF/MANUAL
Switch
Module Slave
Controller
Low Voltage
Terminal Strips
Low Voltage
Circuit Breaker
Low Voltage Panel

7
Optional Manual Isolation Valves
Standard modules are not supplied with isolation valves. Manual or
electrically actuated valves may be ordered as an option from
Multistack. Total Access modules are supplied with manual isolation
valves from the factory and may be upgraded to electrically actuated
valves as an option. Multistack recommends exercising the isolation
valves as part of annual maintenance.
Optional Hot Gas Bypass
As an option, hot gas bypass valves (Sporlan HGBE-8) can be provided
for each circuit. The valve is adjustable from 75 to 150 psi with a
standard setting of 120 psig. A screw on the pilot valve handles the
adjustment.Turning clockwise increases the valve setting; counter-
clockwise rotation decreases the valve setting.
Hot Gas Bypass Valve
Expansion Valves and Liquid Line Sight Glasses
(Standard unit.)
Buttery Valve Actuator for Variable Flow shown on
standard module with extended headers.
Power Actuated
Buttery Valve
Expansion Valve, Subcooling, Liquid Line Sight Glass
• Each circuit on a module has a thermal expansion valve located
between the water header pipes on the condenser side. During
factory run testing the valves are adjusted to maintain 10-12
degrees superheat. Check the superheat periodically to maintain
this range. Subcooling should normally be in a 10-15 degree
range. No external subcooler is used.
• The liquid line sight glass shows green on the indicator bulb if
no moisture is present in the refrigerant circuit. Yellow indicates
potential moisture.
• Sight glasses should show full during normal operation.
• Flashing in the sight glass indicates possible under-charge of the
circuit.
• Refer to the unit nameplate for refrigerant charge information.
Variable Flow and Power Actuated Buttery Valves
For variable ow on the chilled or condenser water side, chiller mod-
ules must be ordered with power actuated buttery valves.
Note: The footprint of an array of standard modules will increase as
the valves add length. Total Access™ module footprint will not change.
1. Multistack recommends controlling the chiller pumps to maintain
pressure dierential across the chiller, not the system. Control
based on system pressure will provide erratic results.
2. Chiller minimum ow bypass for the system can be programmed
in the master controller.
Heat Exchanger Isolation Valves on Total
Access™ Modular Chiller
Expansion
Valves
Sight
Glasses

8
General Data Table
MS010X MS015X MS020X MS030X MS040X MS050X MS070X MS085X
Compressor Type Scroll
Dry Weight (lbs. each) 89 135 135 146 280 293 390 419
Normal Capacity (tons each) 5 7.5 10 15 20 25 30 40
Compressor Quantity/Module 2 2 2 2 2 2 2 2
Oil Charge (pints per compressor) 3.5 6.9 6.9 6.9 9.5 9.5 13.3 13.3
Evaporator (Brazed Plate) Brazed Plate
Weight (lbs.) 50 70 70 90 180 180 220 300
Water Storage (gal.) 1.0 1.6 1.6 2.2 5.5 5.5 7.3 10.1
Circuit Configuration Dual Dual Dual Dual Dual Dual Dual Dual
Quantity 1 1 1 1 1 1 1 1
Header System (gal.) 7 7 7 7 7 7 7 14
Condenser Brazed Plate
Weight (lbs. each) 50 80 80 100 200 200 290 340
Water Storage (gal.) 1.1 2.2 2.2 2.9 6.6 6.6 10.1 12.3
Circuit Configuration Dual Dual Dual Dual Dual Dual Dual Dual
Quantity 1 1 1 1 1 1 1 1
Header System (gal.) 7 7 7 7 7 7 7 14
Refrigerant Type R410A
Charge (lbs./circuit) 6.5 6.5 6.5 10 18 20 23 28
Number of Circuits 2 2 2 2 2 2 2 2
Total Water Volume - gal./module 16.1 17.8 17.8 19.1 26.1 26.1 31.4 50.3
Operating Weight (lbs.) 1,490 (1,620) 1,500 (1,630) 1,510 (1,640) 1,610 (1,740) 1,790 (1,920) 1,970 (2,100) 2,060 ( 2,210 ) 2,350 (2,680)
Shipping Weight (lbs.) 1,330 (1,470) 1,340 (1,480) 1,350 (1,490) 1,450 (1,590) 1,630 (1,770) 1,950 (1,990) 1,890 ( 2,060) 2,380 (2,630)
NOTES: Figures in parentheses ( ) apply to Total Access™ conguration chillers.
Add 75 lbs. per module if equipped with enclosure panels.
Multistack has a policy of continual improvement and reserves the right to change product design, literature and specica-
tions without notice.

9
Module Shipment Package
Pallet #1 — Typical Cabinetry Package (Optional)
1. Top Front Panel
2. Bottom Front Panel
3. Rear Panel/End Panel
4. Side End Panel
5. Master ControllerTop Panel
6. Frame Pieces
7. Frame Connectors, Fasteners, Clips & MagneticTape
12
3
4
5
6
7
Pallet #2 — Buss Connections
8. Buss bar
9. Buss bar insulation
10. Ground strap
11. Junction Box leg
8
9
10
11
NOTE: Before accepting delivery of the Multistack chiller, check
the overall condition of the equipment for damage such as broken
copper lines, oil leaks, damaged controls and/or electrical component
housing, or any major component torn loose from its mounting. If
the Multistack modular chiller is damaged during shipping by the
transportation company or its agent, the installing contractor MUST
promptly le a claim with the transportation company and advise
Multistack. Any discrepancy or damage must be noted on the bill of
lading.
Multistack has a policy of continual improvement and reserves the right to change product design, literature and specica-
tions without notice.

10
Pallet #3 — Typical Piping & Electrical
Package
18. Master Controller*
19. Junction Box
20. Junction Box Cover
21. Sensors / Cables
22. Junction Box Connector (Throat)
23. Power Phase Monitor
24. Buss bar Connector
25. Power Phase Monitor Wire
26. Buss bar Insulation Overlap
27. Phase Monitor Wire
28. Buss bar End Caps
29. Drain Valves & Fittings
30. Module Joining Bolts
31. End Cap for Multiush system (upper)
32. End Caps (evap)
33. Couplings
34. Multiush pipe
35. Solenoid for Multiush system
36. Pipe Stubs
37. End Cap Multiush system (lower)
38. Filter Stops
39. Pet Cock Valves
40. Drain Valves & Fittings
41. Sensor Wells
42. 30 Mesh Filter Strainer
* May be shipped separately to sales oce or job site.
** Shipped inside #19 - Junction Box
18
19
20
21
22
23
24
25 26 27
28
29
30 31
33
37
33
34
35
36
37
39
39 40
41
42
Module on Fork Lift Module on Pallet Jack
Caution: Modules AreTop Heavy
Moving Chiller Modules
Multistack chiller modules MS010 through MS085 may be moved using a fork lift truck, pallet jack or similar equipment. Optional spreader bars for lifting
and factory-installed wheels are available from Multistack. Contact your Multistack representative. For unit weights see the table on Page 8 and the job-
specic as-built submittal drawings.
Multistack has a policy of continual improvement and reserves the right to change product design, literature and specica-
tions without notice.

11
Clearances
Diagram shows typical dimensions and the recommended clearances around the modular chiller. There must be a minimum of six inches clearance over the
top of the chiller, including the top of master controller if installed on top of the module.
For specic unit dimensions, refer to as-built submittal drawings.

12
Standard Modules (Constant Flow Design)
*Standardized drawing of sample customer installation ** Enclosure panels are optional
Module Dimensions (No Panels)
Width (A) Depth (B) Height (C)
Standard 28” 47 ⁄” 64”
Total Access (MS010--050) 32” 56” 67”
Total Access (MS070) 34” 56” 67”
Extended Headers 28” 62 ⁄” 64” Extended Headers 28” 76 ⁄” 64”
A
B
C

13
Variable Flow Design for Chilled and Hot Water
Standard Modules with Extended Headers on
Evaporators and Condensers
Module Dimensions (No Panels)
Width (A) Depth (B) Height (C)
Standard 28” 47 ⁄” 64”
Total Access (MS010--050) 32” 56” 67”
Total Access (MS070) 34” 56” 67”
Extended Headers 28” 62 ⁄” 64” Extended Headers 28” 76 ⁄” 64”
*Standardized drawing of sample customer installation **Enclosure panels are optional
A
B
C

14
Variable Flow Design for Hot Water, Constant Flow for Chilled Water
Standard Modules with Extended Headers on Condensers
Module Dimensions (No Panels)
Width (A) Depth (B) Height (C)
Standard 28” 47 ⁄” 64”
Total Access (MS010--050) 32” 56” 67”
Total Access (MS070) 34” 56” 67”
Extended Headers 28” 62 ⁄” 64” Extended Headers 28” 76 ⁄” 64”
*Standardized drawing of sample customer installation ** Enclosure panels are optional
Module Dimensions (No Panels)
Width (A) Depth (B) Height (C)
Standard 28” 47 ⁄” 64”
Total Access (MS010--050) 32” 56” 67”
Total Access (MS070) 34” 56” 67”
Extended Headers 28” 62 ⁄” 64” Extended Headers 28” 76 ⁄” 64”
B
B
A
C

15
Variable Flow Design for Chilled Water, Constant Flow for Condenser Water
Standard Modules with Extended Headers on Evaporators
Module Dimensions (No Panels)
Width (A) Depth (B) Height (C)
Standard 28” 47 ⁄” 64”
Total Access (MS010--050) 32” 56” 67”
Total Access (MS070) 34” 56” 67”
Extended Headers 28” 62 ⁄” 64” Extended Headers 28” 76 ⁄” 64”
B
*Standardized drawing of sample customer installation ** Enclosure panels are optional
C
A
B

16
Total Access Modules With or Without Variable Flow
Module Dimensions (No Panels)
Width (A) Depth (B) Height (C)
Standard 28” 47 ⁄” 64”
Total Access (MS010--050) 32” 56” 67”
Total Access (MS070) 34” 56” 67”
Extended Headers 28” 62 ⁄” 64” Extended Headers 28” 76 ⁄” 64”
*Standardized drawing of sample customer installation ** Enclosure panels are optional
C
B
A

17
Recommended Piping
All piping must be properly and adequately supported at coupling connections and suitable intervals along the piping runs. Hanger design must
provide for the weight of uids in the piping system when the chiller is in operation.
Multistack modules are equipped with brazed plate heat exchangers made of 316 stainless steel. Multistack recommends use of a 30-mesh system
strainer, Y-type basket or equal, in each condenser and evaporator inlet header.
It is the installing contractor’s responsibility to make sure the water systems have been ushed and the strainers are clean and clear of debris before
starting the chiller. Do not ush piping so as to push debris into or through the through the chiller heat exchangers.
Typical Sensor Wells
Important
Be sure to install the supplied sensor wells in the system piping. The wells should be installed
a few feet from the chiller in the entering and leaving chilled water and entering and leaving
condenser water pipes.
Flow Protection
Proof of chilled water and condenser water ow is required by the Master Controller inputs. Paddle-type or Dierential Pressure (DP) switches may
be used. Switches can be supplied by Multistack as an option, otherwise they are to be eld supplied and installed. Chillers purchased with chilled
or condenser water pump modules have a DP switch installed across the pump to verify operation. Multistack recommends a paddle-type switch be
installed in the leaving chilled water piping using a dierential pressure switch. Install it across the inlet and outlet water connections to the chilled
and/or condenser water piping connections.
System Water Volume
A properly sized chilled water system must have enough time (at least three minutes) to properly control and respond to changes in load and to
prevent short cycling of the chiller. To ensure the system water volume is adequate, a general rule of thumb is:
7-10 gallons of water per ton or Acceptable Chilled Water Volume = Chilled Water Design GPM X 3
If the system heat exchangers, piping and components cannot hold the necessary chilled water volume, a properly sized chilled water storage tank
should be added.
Condenser Water Temperature Control
For installations where entering condenser water temperature could be lower than 65°F Multistack recommends installing a three-way tower bypass
valve to maintain a minimum of 65°F entering condenser water temperature.This is based on a 10°F Delta-T system.
CONDENSER SIDE EVAPORATOR SIDE
Items in This Area Included
with Chiller
To Cooling Tower
or Fluid Cooler
Flow/DP
Switch Isolation
Valves
Sensor Pockets, Sensors
Supplied by Multistack,
installed by others.
Pressure
Taps
Pressure
Taps
Sensor Pockets, Sensors
Supplied by Multistack,
installed by others.
Isolation
Valves
Flow/DP
Switch
Strainer
Condenser
Pump
3-Way
Bypass Valve
CW In
CW Out
Strainer
Chilled Water
Pump
CHW In
CHW Out
Pressure
Taps

18
Pipe System Flushing Procedure
Before connecting the chiller to the condenser and chilled water loop, the piping loops must be ushed with a detergent and hot water (110-130º F) mix-
ture to remove any dirt and organic residue. After removing residue, continue ushing with a dilute phosphoric acid, sulfamic acid or citric acid and water
mixture to remove inorganic scale in the pipe. Cleaning chemicals such as Nu-Calgon“Imperial Grade”Scale Remover part number 4360-84 or equivalent
suitable for both organic residue and scale removal may be substituted. Otherwise detergents and acids shall not be combined unless approved by the
chemical manufacturers. Only chemicals compatible with 316 stainless steel, copper and carbon steel shall be used. (Any concentrations of hydrochloric or
sulfuric acid or chloride containing chemicals shall not be allowed to come in contact with copper brazed 316 stainless steel heat exchangers).
Caution: The use of unapproved chemicals in the chilled or condenser water supplies may damage the heat exchangers. These chemicals in-
clude, but are not limited to, hydrochloric acid, sulfuric acid, muriatic acid, and household bleach. Damage caused by the use of these and other
unapproved chemicals is not covered by warranty. The only approved chemicals for heat exchanger cleaning are phosphoric or sulfamic acids in
concentrations of 10 percent or less by volume. For more information contact your Multistack representative.
While ushing, 30-mesh Y-strainers (or equivalent) must be in place in the system piping and examined periodically as needed to remove collected residue.
The ushing process shall take no less than six hours, or until the strainers are clean after ushing. Old pipe systems with heavy encrustation shall be
ushed a minimum of 24 hours and may require as much as 48 hours before the lters run clean. Detergent and acid concentrations shall be used in strict
accordance with the respective chemical manufacturers instructions. After ushing with the detergent and/or dilute acid concentrations, the system loop
shall be purged with clean water for at least an hour to ush out all residual cleaning chemicals.
Pressure Relief Piping and Refrigerant Monitoring
Multistack chiller modules use a small refrigerant charge (typically 0.6 lbs. per ton) and are often exempt from many requirements of ASHRAE 15 Standard.
Pressure relief valves are not standard on water-cooled modules and must be special ordered if required by local codes.
Water Treatment / Specications
Supply water for both the chilled water and condenser water circuits must be analyzed and treated by a professional water treatment specialist familiar
with the operating conditions and construction materials used in Multistack modular chiller heat exchangers, headers and associated piping. Water quality
for modular chillers using 316 stainless steel brazed plate heat exchangers and carbon steel headers must be maintained within the following parameters:
Water Specications Specications with 25 Percent Glycol
ph >7 and <9 ph >7 and <9
Total Dissolved Solids (TDS) Less than 1000 ppm Total Dissolved Solids 1,000 - 10,000 ppm
Hardness as CaCO330 to 500 ppm Conductivity 1,000 - 15,000 ppm
Alkalinity as CaCO330 to 500 ppm Hardness as CaCO3 30 - 500 ppm
Chlorides Less than 200 ppm Alkalinity as CaCO3 > 500 ppm
Sulfates Less than 200 ppm Chlorides < 200 ppm
Sulfates < 200 ppm

19
Module Assembly
Multistack chiller modules and multiple module chiller arrays are designed to be mounted on steel rails.
1. Determine the entering and leaving evaporator and condenser connection arrangement before setting mounting rails and mod-
ules modules in place. Connections may be at the same end or opposite ends, depending upon jobsite requirements.
2. Chiller modules are to be mounted on 4- x 4- x 4-inch steel
rails or equivalent , 21 inches center-to-center.
3. Place 4- x 4- x 3/8-inch wae type vibration pads every 22 inches
under rails. 50 PSI maximum loading.
Note: Seismic restraint information available from Multistack.
Same End
Opposite End
Vibration Pads
4. Lubricate rails with vegetable shortening or other non-petroleum
lubricant to facilitate installation.

20
Module Assembly
5. Place rst module on the rails. 6. Slide module into position.
7. Place subsequent modules onto rails. 8. Leave sucient space between modules to install
coupling gaskets.
9. Lubricate gaskets with solid vegetable shortening or
other non-petroleum based lubricant.
10. Slide modules together lining up footing holes. Install
bottom joining bolts.
11. Install top joining bolts. 12. Starting with the lower header, install pipe couplings. Position cou-
pling bolts at one and seven o’clock positions as shown for proper frame
installation. Note: Assure proper strainer placement.