Air Cooled Screw Flooded Chillers Cooling Capacity: 77 to ...

AFHX Series 60Hz

Air Cooled Screw Flooded Chillers
Cooling Capacity: 77 to 191 TR (271 to 672 kW)

R134a

Products that perform...By people who care

INTRODUCTION

For more than 100 years, Dunham-Bush has focused on innovative product development. Today, we
provide a full portfolio of HVAC/R products from Fan Coil Units to large centrifugal chillers as well as
many other innovative green solutions. Our commitment to innovation, matched with an aggressive
attitude toward growth, makes Dunham-Bush a leader in global markets. Our product development is
tailored to meet the specific needs of customers, building-by-building, country-by-country and region-by-
region. No other HVAC/R manufacturer takes this approach to meeting your performance expectations.

AFHX, Air Cooled Screw Flooded Chillers, have a cooling capacity range from 77 to 191 TR [271 to 672
kW] in 60Hz version using environmentally sound HFC-134a refrigerant. The entire product line features
energy efficiency, installation ease, control flexibility, high reliability and advanced 2020i controller. The
AFHX range is AHRI certified and ETL listed.

TABLE OF CONTENT

Page No

Introduction .......................................................................................................................................................................................... 2
Nomenclature ....................................................................................................................................................................................... 2
Advantages of Flooded Chiller ............................................................................................................................................................. 3
Unit Features........................................................................................................................................................................................ 5
Operating Benefits ............................................................................................................................................................................... 8
Typical Sequence of Operation............................................................................................................................................................ 9
Application Data ................................................................................................................................................................................. 10
Physical Specifications....................................................................................................................................................................... 11
Performance Data .............................................................................................................................................................................. 13
Dimensional Data ............................................................................................................................................................................... 15
Floor Loading Diagram....................................................................................................................................................................... 18
Dimensional Clearance ...................................................................................................................................................................... 19
Evaporator Water Pressure Drop ....................................................................................................................................................... 20
Sound Pressure Data ......................................................................................................................................................................... 20
Condenser Fan .................................................................................................................................................................................. 21
Electrical Data .................................................................................................................................................................................... 21
Typical Wiring Schematic................................................................................................................................................................... 22
Guide Specifications .......................................................................................................................................................................... 26

NOMENCLATURE

Air Cooled Chiller A F HX 150 T - 6 S R- HR
Flooded Evaporator
Horizontal Screw Compressor HR = Heat Recovery
Nominal TR LN = Low Noise

Blank = R22
R = R134a

S = Standard
Q = Special

5 = 50Hz
6 = 60Hz

T = Optional Two
Compressors

Blank = Standard

-2-

ADVANTAGES OF FLOODED CHILLER

In a flooded evaporator the refrigerant surrounds correspondingly higher Energy Efficiency Ratio
the tubes in the shell and the water to be cooled (EER) i.e. (BTU/Watt) or lower kW/TR.
flows through the tubes. The level of liquid
refrigerant in the shell is maintained by the FIGURE 1
combined action of an electronic level controller
and mod-motor actuated ball valves which
regulates the subcooled liquid refrigerant into the
evaporator. This ensures that all the evaporator
tubes are completely immersed in the liquid
refrigerant for better heat transfer efficiency.

For a Direct Expansion (DX) Evaporator the
refrigerant is expanded into the tubes while the
chilled water is circulated through the shell. A
thermostatic expansion valve is used to throttle
the refrigerant in maintaining constant superheat
of suction gas to the compressor.

The following are the advantages of using a
flooded chiller:

1. Higher Capacity and Higher EER A DX Evaporator uses TXV throttling to
achievable with the Same Compressor maintain about 10°F [5.5°C] to 15°F [8.3°C]
suction superheat to prevent liquid flood back
The flooded evaporator with all the copper to the compressor. In a flooded evaporator, the
tubes immersed in the “boiling” liquid refrigerant boils off in the shell and gas can be
refrigerant enables a small approach sucked out from the top of evaporator back to
temperature between the “boiling” liquid compressor. The suction superheat is usually
refrigerant temperature in the shell and the about 2°F [1.1°C] to 3°F [1.7°C]. Reduction in
outlet chilled water temperature in the suction superheat will further increase the
evaporator tubes to be achieved. This capacity performance of the compressor.
approach temperature or temperature
difference between the evaporating DX Evaporators are typically designed with
temperature of the boiling liquid refrigerant and higher tube velocities to ensure proper oil
the chilled water outlet temperature, for a return to compressor both at full load and at
flooded evaporator, is typically less than 3°F reduced load. This will contribute to higher
[1.7°C]. refrigerant pressure drop through the
evaporator. On the contrary, there is very little
On the contrary, for a DX or Direct Expansion shell side pressure losses for a flooded
Evaporator, the typical approach temperature evaporator. Therefore, lower suction pressure
is between 8°F [4.4°C] to 10°F [5.5°C]. This drop in the flooded design will impose less
simply means that the same compressor in a capacity penalty on the compressor and this
flooded evaporator system will operate at a will further enable the compressor in a flooded
higher saturated evaporating temperature evaporator to generate more capacity than one
when compared to the same compressor in a with a DX Evaporator.
DX Evaporator system, when outlet chilled
water temperatures in both cases are set at
the same temperature.

Figure 1 shows the typical screw compressor
capacity performance curve at a particular
condensing temperature over saturated
evaporating temperature of between 30°F
[-1.1°C] to 50°F [10°C], and the typical power
input curve over the same conditions. It can be
noted that the same compressor when
operating with a flooded evaporator will
generate approximately 8% more cooling
capacity while kW input increases by approx
1.8%. Therefore, the same compressor, when
coupled to a flooded evaporator, will typically
achieve higher cooling capacity with

-3-

ADVANTAGES OF FLOODED CHILLER

2. Better Part Load Performance 5. Maximum Reliability and Redundancy

The Dunham-Bush Air Cooled Flooded Chiller Today, the Dunham-Bush screw compressors
with its sophisticated advanced controller and are increasingly accepted for its reliability. The
patented oil management system has all 2-compressor, 3-compressor and 4-
evaporator tubes completely immersed in the compressor models are designed to have 2
“boiling” liquid refrigerant to achieve superior independent refrigerant circuits for
heat transfer efficiency while ensuring redundancy. For the refrigerant circuits with 2-
adequate oil return to the compressor(s). This compressors (i.e. 3-compressor and 4-
ensures superior full-load efficiency and even compressor models), individual compressor is
better part-load efficiency as the full heat provided with suction stop valve, suction check
transfer surface areas of the evaporator tubes valve, discharge check valve and other
are utilized even at part-load conditions. In isolating valves in the oil management system
Direct Expansion Evaporators, because of the to allow complete isolation of an unlikely faulty
need to maintain adequate refrigerant gas compressor without contaminating the
velocities in the evaporator tubes for proper oil refrigerant system and further allows other
return, it is typical for certain bundles of compressors to continue to operate - thus
evaporator tubes to be “blocked” or “baffled ensuring maximum redundancy
off” at part-load conditions. Therefore not
utilizing the full heat transfer surface of the 6. Cleanable Evaporator
evaporator tubes means lower efficiency when
compared with a flooded evaporator chiller at For a single pass evaporator join in a row, the
part-load conditions. end plates at both ends of the water boxes (2
pass only at return end and 1 pass ‘u’
3. Flash Economizer/ Vapor Injection arrangement only at ‘u’ elbow end) can be
Cycle for Increase Capacity and Higher removed easily without dismantling the chilled
EER water piping connections, for inspection and
for mechanical tubes cleaning with brushes or
The renowned Dunham-Bush screw auto-brush. This will enable low tube fouling
compressor allows for flash economizer vapor factor in the evaporator to be ensured, thus
injection cycle to be incorporated, increasing maintaining system efficiency.
capacity by as much as 25% with marginal
10% to 15% increase in kW-input. Most of 7. Lower Water Side Pressure Drop
Dunham-Bush’s competitors who produce
Rotary Screw Chillers do not incorporate flash- In a DX Evaporator, the water flows
economizer vapor injection cycle- not to transversely over the outside of the tubes. The
mention flooded evaporator! water flow is guided with vertical baffles. This
will have a higher-pressure drop compared to
4. Excellent Capacity Modulation in the water flow in the tubes of a flooded
Response to Building Loads evaporator. In other words, the equivalent
flooded chiller will require smaller water pump
Dunham-Bush utilizes its state-of-the-art to operate at lower power consumption.
advanced controller in combination
with the electronic level controller and 8. Commonly Used In Large Tonnage
modulating motor actuated ball valves to Chillers Where Efficiency Is Critical
ensure precise control of liquid refrigerant to
the flooded evaporator in response to changes As a general rule, DX Evaporators are typically
in cooling load. While maintaining leaving used in small and medium tonnage chillers
chilled water temperatures even at very low where efficiency may not be a primary
load. Whereas most of Dunham-Bush’s consideration but cost is important. However,
competitors utilize orifice plates to modulate with increasing energy cost and the drive to
refrigerant feed to the evaporator, resulting in reduce global warming, flooded evaporator
lower efficiency at low-load and less reliable oil chillers will increasingly become more
return. popular not only in the large tonnage
chillers but also in the small and medium
tonnage chillers. Dunham-Bush, again,
leads the industry in this respect!

-4-

UNIT FEATURES

with the controller through a telephone cable. The
terminal allows carrying out of all program
operations and also allows the unit working
conditions, compressor run times and alarm
history to be displayed. Set points and other
parameters can be modified via the user terminal.
The display has an automatic self-test of the
controller on system start-up. Multiple messages
will be displayed automatically by scrolling from
each message to the next. All of these messages
are spelled out in English on the display terminal.

There are 15 dedicated buttons to enable the user
to access information, based on the security level
of the password. For more detail operation of the
DBG1 Display Terminal, please refer to the Unit
Operation Manual.

Vision 2020i a flexible and advance Easily accessible measurements include:
programmable electronic controller designed D Leaving chilled water temperature
specifically for the application and precise control D Entering chilled water temperature
of Dunham-Bush Rotary Screw compressor D Compressor discharge temperature
chillers. D Leaving chiller water temperature derivative
D Evaporator Pressure
The controller board is provided with a set of D Condenser Pressure
terminals that connect to various devices such as D Compressor amp draw of each compressor
temperature sensors, pressure and current D Compressor elapsed run time of each
transducers, solenoid valves, compressors and
fans contactors, control relays etc. Three sizes of compressor
controller boards are provided to handle different D Compressor starts status
number of input and output requirements: DB3-S D Oil level sensor status
small, DB3-M medium and DB3-L large board. D Water temperature reset value
D Water flow switch status
The unit algorithm program and operating D External start/stop command status
parameters are stored in FLASH-MEMORY that
does not require a back-up battery. The program Optional ambient temperature is available. With
can be loaded through PC or programming key. this option the operator can quickly and
accurately read all significant temperatures and
Vision 2020i controller is equipped with a user eliminate the need for thermometers. Voltmeter is
friendly terminal with a semi-graphic display and also offered as an optional feature.
dedicated keys that provides easy access to the
unit operating conditions, control set points and Capacity Control
alarm history.
Leaving chilled water temperature control is
Each unit’s controller can be configured and accomplished by entering the water temperature
connected to the local DBLAN network that allows setpoint and placing the controller in automatic
multiple units sequencing control without control. The unit will monitor all control functions
additional hardware. The DBLAN is local area and move the slide valve to the required operating
network made up of several chillers’ controller. position. The compressor ramp (loading) cycle is
programmable and may be set for specific
Display and User Terminal building requirements. Remote adjustment of the
leaving chilled water setpoint is accomplished
The Vision 2020i controller is designed to work either through direct BMS protocols connection to
with a user friendly back-lit 132 by 64 pixels
DBG1 Semi-Graphic Display panel connected

-5-

UNIT FEATURES

the controller communication ports, or from an controlled from a PC terminal and optional phone
external hardwired control signal from BMS to modem.
supply a chilled water reset 4 to 20mA analog
input signal. Remote reset of compressor current With various optional add-on cards the
limiting function may be accomplished in a similar Vision2020i controller can also be interfaced
fashion. directly to the Building Management System
(BMS) with the standard communication protocols
System Control using MODBUS, LONWORKS, BACNET MSTP
as well as over IP.
The unit may be started or stopped manually, or
through the use of an external signal from a This sophisticated feature makes servicing easier
Building Automation System. In addition, the and more convenient to the system. The
controller may be programmed with seven-day controller as standard is additionally equipped
operating cycle or other Dunham-Bush control with history files which can be used to take logs
packages may start and stop the system through and which may be retrieved via the phone modem
inter-connecting wiring. or internet connection periodically. Now owners of
multiple buildings have a simple and inexpensive
System Protection method of investigating potential problems quickly
and in a highly cost effective manner.
The following system protection controls will
automatically act to ensure system reliability: REFRIGERATION CYCLE

DLow suction pressure The refrigerant management system, is shown in
DHigh discharge pressure the refrigerant cycle diagram below.
DFreeze protection
DLow differential pressure Liquid refrigerant enters the flooded evaporator
DLow oil level uniformly where it absorbs heat from water
DCompressor run error flowing through the evaporator tubes. The
DPower loss vaporized refrigerant is then drawn into the
DChilled water flow loss suction port of the compressor where the
DSensor error compression begins.
DCompressor over current
DCompressor Anti-recycle This partially compressed gas is then combined
with additional gas from the flash economizer as
The controller can retain up to 99 alarm the vapor injection port at an intermediate
conditions complete with time of failure together pressure is exposed to each interlobe space.
data stamping on critical sensor readings in an Compressed gaseous refrigerant is then
alarm history. This tool will aid service technicians discharged into the integral oil separator where
in troubleshooting tasks enabling downtime and oil, which is contained in the refrigerant vapor, is
nuisance trip-outs to be minimized. removed and returned to the oil sump.

Remote Monitoring High pressure superheated refrigerant is then
discharged into the condenser, where air is drawn
Vision 2020i controller can be completed with an across the condenser by propeller fans which cool
optional RS485 communications card and and condense the refrigerant. This liquid
NETVISOR software for remote monitoring and refrigerant then passes through the first
expansion device and into the flash economizer
where flash gas and liquid refrigerant are
separated.

-6-

UNIT FEATURES

The flash gas is drawn into the vapor injection port Bush air cooled chillers have some of the best
of the compressor. The remaining liquid part-load performance characteristics in the
refrigerant then passes through a second industry when measured in accordance with AHRI
expansion device which reduces the pressure Standard 550/590-2003.
further and it is introduced into the bottom of the
flooded evaporator via an integral distributor. In most cases, actual building system loads are
significantly less than full load design conditions,
By removing the flash gas from the flash therefore chillers operate at part load most of the
economizer at an intermediate pressure, the time.
enthalpy of the refrigerant flowing into the
evaporator is reduced. This increases the Dunham-Bush air cooled chillers combine the
refrigeration effect and improves the efficiency of efficient operation of multiple compressors with an
the refrigeration cycle. economizer cycle and advanced controller to yield
the best total energy efficiency and significant
Refrigerant flow into and out of the flash operating saving under any load.
economizer is controlled by modulating valves
which eliminate the energy wasting hot gas When specifying air conditioning equipment, it is
bypass effect inherent with fixed orifices. important to consider the system load
characteristics for the building application. In a
PART-LOAD PERFORMANCE typical city, the air conditioning load will vary
according to changes in the ambient temperature.
Through the use of flash economizer modulating Weather data compiled over many years will
flow control and multiple compressors, Dunham- predict the number of hours that equipment will
operate at various load percentages.

-7-

OPERATING BENEFITS

EFFICIENCY AND RELIABILITY D IEEE.

Energy Efficiency D Safety quality license for import boiler and
pressure vessel, China.
D Designed to provide the greatest amount of
cooling for the least power input over the entire Refrigerant Compatibility
operating range of your building.
D Designed to operate with environmentally
D Delivers outstanding efficiency and total sound and economically smart HFC-134a with
energy savings through the utilization of proven efficiency and reliability.
economizer cycle and advanced controller
staging producing greater capacity with fewer D Consult Factory for use of other HFC
compressors. refrigerants.

D Maximized performance through computer- Control Flexibility
matched components and multiple
compressors on a single refrigerant circuit. D Controller-based with DDC (direct digital
control) features precise push button control
D High efficiency oil recovery system guarantees over every aspect of operation with built-in
removal of oil carried over in the refrigerant standard features that allow extra energy
and maintains the heat exchangers at their savings on start-up and throughout the life of
maximum efficiency at both full and part load. your equipment.

Operational Advantages D Ensured uniform compressor loading and
optimal energy efficiency through controller to
D Dramatic payback in reduced maintenance controls which utilize pressure transducers to
and overhaul costs both in downtime and in measure evaporator and condenser pressure.
labor expenditures.
D Lower energy costs resulting from automatic
D Ease of troubleshooting through controller load monitoring and increased accuracy and
retention of monitored functions. efficiency in compressor staging.

D Factory run tested. D Monitor your chiller's key functions from a
remote location with a simple, low cost, phone
Safety Code modem option.

D ASME Boiler and Pressure Vessel Code, D Proactive control anticipates problems and
Section VIII Division 1 "Unfired Pressure takes corrective action before they occur.
Vessels". Controls will unload compressor(s) if head or
suction pressure approach limits. This will
D JKKP Code. enable unit to stay on line while warning
D ASME Standard B31.5 Refrigeration Piping. operator of potential problems.
D ASHRAE Standard 15 Safety Code for

Mechanical Refrigeration.

-8-

TYPICAL SEQUENCE OF OPERATION

The Dunham-Bush air cooled water chiller match applied load and hold leaving chilled water
depends mainly on its on-board controller for temperature at setpoint.
control. Operation described is for a two-
compressor units and is very similar for single If the applied load is greater than one compressor
compressor units. can handle, it will load fully and then the controller
will call for a second compressor. After one
For initial start-up, the following conditions must minute, the second compressor will start in the
be met: same manner as the first. Then both compressors
will be commanded to adjust load to 50%. They
D Power supply to unit energized. are gradually loaded up together until the applied
load is satisfied. In this way the two compressors
D Unit circuit breakers in the ‘on’ position. share the load equally.

D Control power switch ‘on’ for at least 15 If the applied load decreases to the point that both
minutes. Compressor switches ‘on’. compressors are running at about 40% capacity,
the computer shuts down the lag compressor and
D Reset pressed on controller keypad. loads the remaining compressor to about 80%. If
applied load decreases further, the remaining
D Chilled water pump running and chilled water compressor unloads proportionately. If applied
flow switch made. load decreases to less than the minimum capacity
of one compressor, the leaving chilled water
D Leaving chilled water temperature at least 2°F temperature will decline to 2°F [1.1°C] below
[1.1°C] above setpoint. setpoint, at which time the lead compressor will
shut down. It will restart automatically if leaving
D All safety conditions satisfied. chilled water temperature rises to 2°F [1.1°C]
above setpoint and both 15 minute anti-recycle
After all above conditions are met, the controller and one minute start delay timers are satisfied.
will call for the lead compressor to start. The
compressor 15-minute anti-recycle timer is During start-up operation, the computer monitors
initiated at compressor start. the difference between discharge and suction
pressures to ensure that minimum of 30psi
The controller monitors compressor amps, volts, [2bar] differential is available for compressor
leaving water temperature and suction and lubrication. If the difference falls below a minimum
discharge pressures. The compressor and cooling of 30psi [2bar], the computer closes refrigerant
capacity is controlled by pulsed signals to load flow control valves, starving the evaporator,
and unload solenoid valves on the compressor. causing evaporator pressure to drop, increasing
When the compressor starts, it is fully unloaded, differential pressure. This is especially helpful at
reducing about 25% of its full load capacity. As startup, when warm chilled water and low ambient
the computer gives it load signals, capacity temperature would cause a low head situation.
gradually increases. The rate of compressor This feature is called EPCAS: Evaporator
loading is governed by ramp control which is Pressure Control at Startup. It is one of several
adjustable in the computer. proactive control features of the controller which
overcome potential problems while continuing
The computer responds to leaving chilled water operation.
temperature and its rate of change which is
proportional and derivative control. If leaving Two additional proactive features are low suction
chilled water temperature is within the deadband and high discharge pressure override. If operating
(+/-0.8°F [0.5°C] from setpoint), no load or unload pressures approach trip level, compressors are
commands are given. If chilled water temperature unloaded as necessary to continue operation.
is above deadband, the computer will continue
loading the compressor until a satisfactory rate of
decline is observed. If leaving chilled water
temperature is below the deadband, the
compressor is commanded to unload. Thus the
compressor capacity is continuously modulated to

-9-

APPLICATION DATA

Low Ambient Operation / Freeze USgal [11 liters] for process, low load applications
Protection with small temperature ranges and/or vastly
fluctuating load conditions.
If unit is required to operate below 20°F [-7°C],
optional head pressure control is required. Glycol Freeze Protection
Immersion heater and circulating pump need to
be provided to be in operation when the chiller is If the chiller or fluid piping may be exposed to
not operating. Glycol is recommended for added temperatures below freezing, glycol protection is
protection. If wind in area is over 5 mph [8 kph], a recommended. The re-commended protection is
wind barrier is recommended. 10°F [5.6°C] below the minimum ambient
temperature. Use only glycol solutions approved
Desuperheaters for heat exchanger duty. The use of automotive
anti-freeze is not recommended because they
A hot gas desuperheater can be factory supplied have short-lived inhibitors and fouling of the
for field installation. Suitable fittings in refrigerant vessels will occur. If the equipment is exposed to
lines with shut off valves can be supplied. Consult freezing temperature and not being used, the
factory for further details. vessels and piping should be drained.

Water Circuit The use of glycol causes a performance derate as
shown below which needs to be included in the
Constant water flow required with a minimum of 3 unit selection procedure.
USgal per TR [3.3 liters / kW°] increasing up to 10

Ethylene Glycol Freeze Point C1 K1 G1 P1
Capacity Factor kW Rate Flow Factor P.D. Factor
% E. G. °F °C
By Weight 0.995 0.998 1.019 1.050
26.2 -3.2 0.991 0.997 1.030 1.083
10 22.4 -5.3 0.988 0.996 1.044 1.121
15 17.8 -7.9 0.984 0.995 1.060 1.170
20 12.6 -10.8 0.981 0.994 1.077 1.219
25 6.7 -14.1 0.977 0.992 1.097 1.275
30 0.0 -17.8 0.973 0.991 1.116 1.331
35 -10.0 -23.3 0.968 0.990 1.138 1.398
40 -17.5 -27.5 0.964 0.989 1.161 1.466
45 -28.9 -33.8
50

Propylene Glycol

% P. G. Freeze Point C2 K2 G2 P2
By Weight Capacity Factor kW Rate Flow Factor P. D. Factor
°F °C
10 0.988 0.994 1.005 1.019
15 26.1 -3.3 0.984 0.992 1.008 1.031
20 0.978 0.990 1.010 1.051
25 22.8 -5.1 0.970 0.988 1.015 1.081
30 0.962 0.986 1.021 1.120
19.1 -7.2

14.5 -9.7

8.9 -12.8

Correction Factor - Elevation Correction Factor - FF

Elevation above Sea Level Capacity kW Fouling Factor Capacity kW
Correction Correction Correction Correction
Feet Meters Factor hr.ft².°F/BTU m².°C/kW
Factor Factor Factor Factor
0 0 0.00010 0.018
2000 600 1.00 1.00 0.00025 0.044 1.000 1.000
4000 1200 0.00050 0.088
6000 1800 0.99 1.01 0.990 0.995

0.98 1.02 0.970 0.990

0.97 1.03

- 10 -

PHYSICAL SPECIFICATIONS

Model AFHX 75-6SR 80T-6SR 90T-6SR 100-6SR 115-6SR

Unit Nominal Capacity TR[kW] 70 [246] 74 [260] 84 [295] 88 [311] 103 [362]
Unit Nominal Power Input kW 86 92 104 110 128

COMPRESSOR

Model (Qty) HX 1512 (1) HX 1309 (2) HX 1311 (2) HX 1709 (1) HX 1711 (1)
RPM 3550 3550 3550 3550 3550
Min. % Unit Capacity 25% 12.5% 12.5% 25% 25%

EVAPORATOR

Model (Qty) B1R (1) B1R (1) C1R (1) C1R (1) D1R (1)

Water Connector inches[mm] 5 [127] 5 [127] 5 [127] 5 [127] 6 [152]

Nominal Water Flow / Pressure Drop 168.7/ 9.3 177.3/ 10.2 201.2/ 8.4 212.3/ 9.3 247.1/ 7.4
USgpm/ ft.wg[m³/hr/ kPa] [38.3/ 27.8] [40.3/ 30.5] [45.7/ 25.1] [48.2/ 27.8] [56.1/ 22.1]

Min/ Max Water Flow USgpm[m³/hr] 63.0/ 313.0 63.0/ 313.0 79.0/ 396.5 79.0/ 396.5 105.0/ 523.0
[14.3/ 71.1] [14.3/ 71.1] [17.9/ 90.0] [17.9/ 90.0] [23.8/ 118.7]
Min/ Max Water Pressure Drop ft.wg[kPa]
1.6/ 28.3 1.6/ 28.3 1.6/ 28.7 1.6/ 28.7 1.6/ 28.5
[4.8/ 84.6] [4.8/ 84.6] [4.8/ 85.8] [4.8/ 85.8] [4.8/ 85.2]

CONDENSER

Coil Rows Deep/ Total Face Area ft²[m²] 3/ 121.9 [11.3] 3/ 121.9 [11.3] 4/ 121.9 [11.3] 4/ 121.9 [11.3] 4/ 162.6 [15.1]
6 6 6 6 8
No. Of Fan
31.5 [800](6) 31.5 [800](6) 31.5 [800](6) 31.5 [800](6) 31.5 [800](8)
Fan Diameter (Qty) inches[mm] 2(6) 2(6) 2(6) 2(6) 2(8)
Motor kWi (Qty) 3.8(6) 3.8(6) 3.8(6) 3.8(6) 3.8(8)
74466 72954 72954
FLA, AMP (Qty) 76734 101304
[130386] [126532] [123963] [123963] [172136]
Total Air Flow cfm[m³/hr] 45 [7.2] 45 [7.2] 45 [7.2] 45 [7.2] 45 [7.2]

Min. Operating Ambient °F[°C] ELECTRICAL

Nominal Voltage 460/3/60 460/3/60 460/3/60 460/3/60 460/3/60
Unit RLA A 140 151 167 173 200
Unit Max. Inrush A 231 195 203 266 312

GENERAL

Unit Length inches[mm] 150 [3810] 150 [3810] 150 [3810] 150 [3810] 192 [4877]

Unit Width inches[mm] 88 [2235] 88 [2235] 88 [2235] 88 [2235] 88 [2235]

Unit Height inches[mm] 87.5 [2222] 87.5 [2222] 87.5 [2222] 87.5 [2222] 87.5 [2222]

Shipping Weight lbs[kg] 8526 [3867] 9063 [4111] 9601 [4355] 9322 [4228] 10919 [4953]

Operating Weight lbs[kg] 8641 [3920] 9179 [4164] 9749 [4422] 9470 [4295] 11112 [5040]

Operating Charge R134a lbs[kg] 205 [93] 216 [98] 245 [111] 260 [118] 302 [137]

Note: Nominal capacity is based on evaporator LWT 44°F and condenser ambient 95°F, actual capacity depends on the specified operating
conditions.

- 11 -

PHYSICAL SPECIFICATIONS

Model AFHX 125T-6SR 135-6SR 150-6SR 150T-6SR 175T-6SR 190-6SR

Unit Nominal Capacity TR [kW] 110 [387] 121 [427] 132 [466] 137 [482] 158 [556] 171 [603]
Unit Nominal Power Input kW 138 150 162 172 192 213

COMPRESSOR

Model (Qty) HX 1509 (2) HX 1811 (1) HX 1813 (1) HX 1512 (2) HX 1709 (1) HX 1816 (1)
HX 1512 (1)
RPM 3550 3550 3550 3550 3550
Min. % Unit Capacity 12.5% 25% 25% 12.5% 3550 25%

12.5%

EVAPORATOR

Model (Qty) D2R (1) D2R (1) J1R (1) J1R (1) K1R (1) K2R (1)

Water Connector inches[mm] 6 [152] 6 [152] 6 [152] 6 [152] 6 [152] 6 [152]

Nominal Water Flow / Pressure Drop 264.3/ 6.8 291.6/ 8.1 318.0/ 11.2 329.3/ 11.9 380.1/ 13.3 411.7/ 13.0
USgpm / ft.wg [m³/hr / kPa] [60.0/ 20.3] [66.2/ 24.2] [72.2/ 33.5] [74.8/ 35.6] [86.3/ 39.8] [93.5/ 38.9]

Min/ Max Water Flow USgpm[m³/hr] 117.0/ 587.0 117.0/ 587.0 117.0/ 588.0 117.0/ 588.0 128.0/ 640.0 142.0/ 705.0
[26.6/ 133.2] [26.6/ 133.2] [26.6/ 133.4] [26.6/ 133.4] [29.1/ 145.3] [32.2/ 160.0]

Min/ Max Water Pressure Drop ft.wg[kPa] 1.6/ 28.8 1.6/ 28.8 1.9/ 33.8 1.9/ 33.8 1.9/ 33.9 1.9/ 34.3
[4.8/ 86.1] [4.8/ 86.1] [5.7/ 101.1] [5.7/ 101.1] [5.7/ 101.4] [5.7/ 102.6]

CONDENSER

Coil Rows Deep/ Total Face Area ft²[m²] 4/ 162.6 [15.1] 4/ 162.6 [15.1] 4/ 188.2 [17.5] 4/ 188.2 [17.5] 4/ 235.3 [21.9] 4/ 235.3 [21.9]

No. Of Fan 8 8 8 8 10 10

Fan Diameter (Qty) inches[mm] 31.5 [800](8) 31.5 [800](8) 31.5 [800](8) 31.5 [800](8) 31.5 [800](10) 31.5 [800](10)
Motor kWi (Qty) 2(8) 2(8) 2(8) 2(8)
2(10) 2(10)

FLA, AMP (Qty) 3.8(8) 3.8(8) 3.8(8) 3.8(8) 3.8(10) 3.8(10)

Total Air Flow cfm[m³/hr] 97272 97272 103236 101388 126735 129045
[165285] [165285] [175419] [172278] [215348] [219273]

Min. Operating Ambient °F[°C] 45 [7.2] 45 [7.2] 45 [7.2] 45 [7.2] 45 [7.2] 45 [7.2]

ELECTRICAL

Nominal Voltage 460/3/60 460/3/60 460/3/60 460/3/60 460/3/60 460/3/60
Unit RLA A 224 229 243 264 335 319
Unit Max. Inrush A 294 335 497 356 426 536

GENERAL

Unit Length inches[mm] 192 [4877] 192 [4877] 202.5 [5144] 192 [4877] 234 [5944] 234 [5944]

Unit Width inches[mm] 88 [2235] 88 [2235] 88 [2235] 88 [2235] 88 [2235] 88 [2235]

Unit Height inches[mm] 87.5 [2222] 87.5 [2222] 96.5 [2451] 96.5 [2451] 96.5 [2451] 96.5 [2451]

Shipping Weight lbs[kg] 12034 [5458] 11495 [5214] 12329 [5593] 12896 [5850] 15361 [6968] 14579 [6613]

Operating Weight lbs[kg] 12246 [5555] 11708 [5311] 12581 [5707] 13148 [5964] 15641 [7095] 14882 [6750]

Operating Charge R134a lbs[kg] 322 [146] 355 [161] 388 [176] 401 [182] 483 [219] 522 [237]

Note: Nominal capacity is based on evaporator LWT 44°F and condenser ambient 95°F, actual capacity depends on the specified operating
conditions.

- 12 -

PERFORMANCE DATA

Ambient Temperature, °F

LWT Model 85.0 95.0 105.0 115.0
°F AFHX
kW°
TR kW° kWI TR kW° kWI TR kW° kWI TR 201.3 kWI
213.2
75-6SR 67.7 238.0 63.2 65.0 228.4 72.8 61.6 216.5 84.9 57.3 239.7 100.2
92.0 60.6 252.2 108.3
80T-6SR 70.5 247.9 68.7 68.2 240.0 79.0 65.0 228.4 105.5 68.2 294.2 125.5
113.4 71.7 315.1 135.1
90T-6SR 80.7 283.6 78.4 77.5 272.4 90.6 73.3 257.9 128.8 83.7 345.5 153.3
140.3 89.6 375.9 166.7
100-6SR 85.5 300.8 83.9 81.7 287.3 97.0 77.2 271.4 154.8 98.2 389.1 184.6
169.2 106.9 452.9 202.4
115-6SR 99.3 349.1 95.6 95.1 334.6 110.3 90.0 316.4 180.0 110.6 484.3 215.9
198.6 128.8 210.2 236.4
40.0 125T-6SR 106.0 372.9 104.4 101.7 357.7 120.3 96.4 338.9 225.5 137.7 222.5 270.2
85.0 59.8 250.3 100.3
135-6SR 117.5 413.2 114.3 112.1 394.4 132.2 105.8 372.2 92.3 63.3 263.5 108.5
105.9 71.2 307.1 125.5
150-6SR 128.3 451.3 124.5 122.4 430.4 144.7 115.3 405.7 113.9 74.9 328.9 135.0
129.5 87.3 360.7 153.4
150T-6SR 132.7 466.8 132.5 126.7 445.6 153.5 119.4 419.9 140.7 93.5 392.7 166.8
155.6 102.6 406.6 184.5
175T-6SR 152.8 537.5 147.3 146.4 514.7 169.9 138.4 486.6 169.8 111.7 472.8 202.7
180.6 115.6 506.1 215.5
190-6SR 166.1 584.2 165.1 158.3 556.7 190.7 149.1 524.3 199.6 134.4 219.5 235.6
226.6 143.9 232.1 270.4
75-6SR 70.3 247.3 63.3 67.5 237.4 73.0 64.1 225.5 86.0 62.4 261.2 100.4
92.9 66.0 275.1 108.8
80T-6SR 73.2 257.5 69.1 71.0 249.6 79.2 67.6 237.7 106.3 74.3 320.7 125.3
114.2 78.2 343.5 136.0
90T-6SR 83.9 294.9 78.8 80.6 283.3 90.8 76.3 268.5 129.9 91.2 376.9 153.1
141.0 97.7 410.3 166.5
100-6SR 88.8 312.4 84.3 85.0 298.9 97.3 80.4 282.7 155.5 107.2 424.8 185.3
170.1 116.7 493.6 203.1
115-6SR 103.1 362.7 96.0 98.9 347.8 110.7 93.7 329.6 181.0 120.8 529.0 216.5
200.3 140.3 236.8
42.0 125T-6SR 110.1 387.1 104.8 105.8 371.9 120.7 100.4 353.1 227.5 150.4 270.8

135-6SR 122.0 429.1 114.8 116.7 410.3 132.7 110.3 387.8

150-6SR 133.3 468.8 125.0 127.3 447.6 144.7 120.1 422.5

150T-6SR 137.9 485.0 133.1 131.8 463.5 154.0 124.4 437.4

175T-6SR 158.8 558.4 147.8 152.2 535.3 170.5 144.1 506.8

190-6SR 172.6 607.0 165.8 164.7 579.2 190.7 155.4 546.5

75-6SR 73.0 256.9 63.4 70.2 247.0 73.6 66.7 234.7

80T-6SR 76.1 267.5 69.3 73.8 259.5 79.9 70.3 247.3

90T-6SR 87.0 306.1 79.0 83.8 294.5 91.6 79.5 279.7

100-6SR 92.2 324.3 84.4 88.4 310.8 98.2 83.8 294.5

115-6SR 107.1 376.6 96.1 102.8 361.7 111.7 97.6 343.2

44.0 125T-6SR 114.3 402.0 105.0 110.0 386.8 121.8 104.5 367.6

135-6SR 126.7 445.6 114.9 121.4 426.8 133.8 115.0 404.3

150-6SR 138.5 487.0 125.7 132.4 465.5 146.5 125.3 440.7

150T-6SR 143.3 503.8 133.9 137.1 482.0 156.0 129.6 455.9

175T-6SR 164.9 579.9 148.0 158.2 556.4 172.0 150.1 528.0

190-6SR 179.3 630.5 166.5 171.4 602.7 192.9 162.0 569.6

Notes: 1.) Ratings based on 10°F water range in evaporator and .0001 hr.ft².°F/BTU fouling factor.

2.) Interpolation between ratings is permissible but extrapolation is NOT.
3.) kWI is for compressor input.

4.) Unit is running on part load for ambient temperature 115°F and above due to current limiter.

- 13 -

PERFORMANCE DATA

Ambient Temperature, °F

LWT Model 85.0 95.0 105.0 115.0
°F AFHX

TR kW° kWI TR kW° kWI TR kW° kWI TR kW° kWI

75-6SR 75.8 266.4 63.8 72.9 256.5 74.0 69.5 244.3 85.9 65.1 228.8 101.3
68.7 241.7 109.0
80T-6SR 79.0 277.7 69.3 76.6 269.4 80.3 73.1 257.2 92.9 77.5 272.4 125.9
81.6 287.0 135.8
90T-6SR 90.3 317.7 79.4 87.0 305.8 92.0 82.8 291.2 106.5 95.1 334.6 153.8
101.8 358.0 167.2
100-6SR 95.8 336.9 84.9 91.8 323.0 98.6 87.2 306.8 114.9 111.8 393.1 184.8
121.7 428.1 202.3
115-6SR 111.2 391.1 96.6 106.9 375.9 112.1 101.6 357.4 130.5 126.0 443.0 215.7
146.3 514.4 237.1
46.0 125T-6SR 118.6 417.2 105.5 114.2 401.7 122.4 108.8 382.5 141.4 157.0 552.1 270.1
67.6 237.7 101.9
135-6SR 131.6 462.8 115.5 126.1 443.3 134.4 119.6 420.5 156.9 71.4 251.3 110.4
80.5 283.0 126.5
150-6SR 143.7 505.5 125.8 137.6 484.0 146.8 130.4 458.5 171.1 84.8 298.2 136.3
98.8 347.4 154.4
150T-6SR 148.8 523.3 134.1 142.4 500.9 156.2 135.0 474.7 182.0 105.8 371.9 168.6
116.2 408.6 186.7
175T-6SR 171.2 602.0 148.9 164.4 578.2 172.9 156.2 549.5 200.3 126.6 445.3 204.3
131.0 460.9 217.9
190-6SR 186.1 654.6 167.4 178.1 626.5 192.0 168.6 593.1 228.2 152.0 534.6 238.0
163.4 574.6 273.1
75-6SR 78.6 276.4 64.0 75.6 265.8 74.0 72.1 253.6 86.6 70.3 247.3 102.0
74.3 261.2 110.6
80T-6SR 81.8 287.6 69.8 79.4 279.4 80.3 76.0 267.1 93.7 83.8 294.5 127.3
88.4 310.8 137.0
90T-6SR 93.6 329.3 79.9 90.2 317.1 92.2 85.9 302.2 107.5 102.9 362.0 154.9
110.1 387.1 168.6
100-6SR 99.3 349.1 85.6 95.2 334.9 98.9 90.5 318.4 115.7 121.1 425.8 187.1
132.0 464.2 205.0
115-6SR 115.2 405.3 97.5 110.8 389.8 112.3 105.5 370.9 131.2 136.6 480.4 218.4
158.4 557.1 239.3
48.0 125T-6SR 123.1 432.8 106.3 118.4 416.6 122.4 112.9 397.0 143.4 170.3 599.1 273.4

135-6SR 136.4 479.7 117.1 130.8 459.8 135.0 124.2 436.7 158.0

150-6SR 149.0 524.0 127.5 142.8 502.2 147.1 135.4 476.1 172.4

150T-6SR 154.3 542.5 135.6 147.8 519.7 156.6 140.2 492.9 183.3

175T-6SR 177.5 624.2 150.0 170.5 599.7 173.1 162.2 570.3 202.3

190-6SR 193.0 678.7 168.8 184.8 649.9 193.5 175.1 615.9 229.8

75-6SR 81.5 286.6 64.6 78.5 276.0 74.2 74.9 263.5 86.8

80T-6SR 84.9 298.5 70.2 82.4 289.9 80.7 78.9 277.4 94.1

90T-6SR 97.1 341.5 80.7 93.6 329.3 92.5 89.3 314.1 108.1

100-6SR 103.0 362.3 86.2 98.9 347.8 99.0 94.1 330.9 116.3

115-6SR 119.6 420.5 98.2 115.1 404.7 112.9 109.6 385.5 132.0

50.0 125T-6SR 127.6 448.6 107.3 123.0 432.4 122.8 117.3 412.6 143.8

135-6SR 141.5 497.5 117.4 135.8 477.7 135.4 129.1 453.9 158.9

150-6SR 154.6 543.8 127.9 148.3 521.7 147.8 140.8 495.2 174.2

150T-6SR 160.0 562.7 136.0 153.5 539.9 157.1 145.7 512.4 185.5

175T-6SR 184.1 647.3 151.3 177.1 622.9 174.1 168.5 592.8 203.5

190-6SR 200.2 704.2 169.3 192.0 675.1 195.0 182.2 640.7 231.7

Notes: 1.) Ratings based on 10°F water range in evaporator and .0001 hr.ft².°F/BTU fouling factor.

2.) Interpolation between ratings is permissible but extrapolation is NOT.
3.) kWI is for compressor input.

4.) Unit is running on part load for ambient temperature 115°F and above due to current limiter.

- 14 -

DIMENSIONAL DATA

AFHX 75-6SR, 100-6SR

AFHX 80T-6SR, 90T-6SR

AFHX 115-6SR, 135-6SR

Note : All dimensions are in inches[mm].

- 15 -

DIMENSIONAL DATA

AFHX 125T-6SR, 150T-6SR

AFHX 150-6SR

Note : All dimensions are in inches[mm].

- 16 -

DIMENSIONAL DATA

AFHX 175T-6SR

AFHX 190-6SR

Note : All dimensions are in inches[mm].

- 17 -

FLOOR LOADING DIAGRAM

a.) POINT LOAD LOCATION – inches[mm]

Model AFHX A Dim. B Dim. C Dim. D Dim. E Dim.

75-6SR 86[2184] 18[457] 57[1448] 57[1448] 18[457]
80T-6SR 86[2184] 18[457] 57[1448] 57[1448] 18[457]
90T-6SR 86[2184] 18[457] 57[1448] 57[1448] 18[457]
100-6SR 86[2184] 18[457] 57[1448] 57[1448] 18[457]
115-6SR 86[2184] 18[457] 78[1981] 78[1981] 18[457]
125T-6SR 86[2184] 18[457] 78[1981] 78[1981] 18[457]
135-6SR 86[2184] 18[457] 78[1981] 78[1981] 18[457]
150-6SR 86[2184] 18[457] 83-1/4[2115] 83-1/4[2115] 18[457]
150T-6SR 86[2184] 18[457] 78[1981] 78[1981] 18[457]
175T-6SR 86[2184] 18[457] 99[2515] 99[2515] 18[457]
190-6SR 86[2184] 18[457] 99[2515] 99[2515] 18[457]

b.) POINT LOAD DATA – lbs [kg]

Model Pos. Pos. Pos. Pos. Pos. Pos. Total Operating
AFHX #1 #2 #3 #4 #5 #6 Weight

75-6SR 1297 [588] 1464 [664] 1630 [739] 1465 [665] 1416 [642] 1368 [621] 8641 [3919]
80T-6SR 1633 [741] 1578 [716] 1523 [691] 1462 [663] 1482 [672] 1501 [681] 9179 [4164]
90T-6SR 1737 [788] 1675 [760] 1612 [731] 1550 [703] 1575 [714] 1599 [725] 9749 [4422]
100-6SR 1415 [642] 1614 [732] 1813 [822] 1598 [725] 1543 [700] 1487 [674] 9470 [4296]
115-6SR 1607 [729] 1849 [839] 2091 [948] 1795 [814] 1855 [841] 1915 [869] 11112 [5040]
125T-6SR 2169 [984] 2094 [950] 2020 [916] 1819 [825] 1987 [901] 2156 [978] 12246 [5555]
135-6SR 1700 [771] 1954 [886] 2208 [1002] 1886 [855] 1949 [884] 2011 [912] 11708 [5311]
150-6SR 1794 [814] 2102 [953] 2411 [1094] 2057 [933] 2091 [948] 2125 [964] 12581 [5707]
150T-6SR 2323 [1054] 2258 [1024] 2192 [994] 1994 [904] 2125 [964] 2256 [1023] 13148 [5964]
175T-6SR 3046 [1382] 2787 [1264] 2528 [1147] 2145 [973] 2427 [1101] 2708 [1228] 15641 [7095]
190-6SR 2056 [933] 2257 [1024] 2458 [1115] 2715 [1232] 2704 [1227] 2692 [1221] 14882 [6750]

- 18 -

DIMENSIONAL CLEARANCE

SPACE REQUIREMENTS

Single Pit (See Note 2)

Double Pit (See Note 2)

Multi Pit

Corner Wall Notes:

1.) All dimensions are minimal, unless
otherwise noted.

2.) Pit installations are not re-
commended. Re-circulation of hot
condenser air in combination with
surface air turbulence cannot be
predicted. Hot air re-circulation will
severely affect unit efficiency (EER)
and can cause high pressure or fan
motor temperature trips. Dunham-
Bush will not be responsible for
ducting fans to a higher level to
alleviate the above mentioned
conditions.

- 19 -

EVAPORATOR WATER PRESSURE DROP

IMPERIAL UNITS

100

PRESSURE DROP - ft.wg. 10 AFHX 75-6SR
AFHX 80T-6SR
AFHX 190-6SR
AFHX 90T-6SR
AFHX 100-6SR

AFHX 115-6SR
AFHX 150-6SR
AFHX 150T-6SR

AFHX 125T-6SR
AFHX 135-6SR

AFHX 175T-6SR

1 100 1000
10 WATER FLOW RATE - USgpm

S. I. UNITS

PRESSURE DROP - kPa 1000 AFHX 75-6SR
100 AFHX 80T-6SR
10
AFHX 90T-6SR
AFHX 100-6SR

AFHX 115-6SR
AFHX 150-6SR
AFHX 150T-6SR

AFHX 125T-6SR
AFHX 135-6SR

AFHX 175T-6SR

AFHX 190-6SR

1 100 1000
10 WATER FLOW RATE - m³/hr

SOUND PRESSURE DATA

Octave Band (Hz) Total

Model 63 125 250 500 1K 2K 4K 8K dB (A)

AFHX 75-6SR 45 44 50 52 57 55 51 43 61
62
AFHX 80T-6SR 46 45 51 53 58 56 51 44 62
63
AFHX 90T-6SR 46 45 51 53 58 56 51 44 64
63
AFHX 100-6SR 48 46 52 53 60 57 52 44 66
66
AFHX 115-6SR 48 47 53 54 61 58 53 45 63
65
AFHX 125T-6SR 47 46 52 54 59 57 52 45 67

AFHX 135-6SR 50 49 54 55 63 60 55 46

AFHX 150-6SR 51 49 55 55 63 60 55 46

AFHX 150T-6SR 48 47 52 54 60 57 53 45

AFHX 175T-6SR 49 48 54 55 61 59 54 46

AFHX 190-6SR 51 49 55 56 63 61 55 46

Note: Unit Sound Pressure Level (Lp) @ 33 ft [10m] (free field), ± 2 dB tolerance.

- 20 -

CONDENSER FAN

FAN POSITION NUMBER & CYCLING SEQUENCE

AFHX 75-6SR, 100-6SR, AFHX 115-6SR, 135-6SR, 150-6SR,
80T-6SR, 90T-6SR 125T-6SR, 150T-6SR

BASE FANS 2, 4, 6 BASE FANS 2, 4, 6, 8
STAGE 1 1, 5 STAGE 1 1, 5
STAGE 2 3 STAGE 2 3, 7

AFHX 175T-6SR, 190-6SR

BASE FANS 2, 4, 6, 8, 10
STAGE 1 1, 5
STAGE 2 3, 7
STAGE 3 9

ELECTRICAL DATA

MODEL COMPRESSOR DATA COND. FAN MOTOR DATA UNIT ELECTRICAL DATA
AFHX FLA MCA MFS
MODEL QTY RLA LRA QTY HP FLA

75-6SR HX1512 1 107 625 6 2 3.8 130 157 250
3.8 139 153 200
80T-6SR HX1309 2 58 325 6 2 3.8 157 174 200
3.8 166 202 300
90T-6SR HX1311 2 67 325 6 2 3.8 192 233 350
3.8 208 231 300
100-6SR HX1709 1 143 730 6 2 3.8 224 273 450
3.8 243 297 500
115-6SR HX1711 1 162 845 8 2 3.8 256 285 350

125T-6SR HX1509 2 89 500 8 2 450

135-6SR HX1811 1 194 915 8 2 600

150-6SR HX1813 1 213 1400 8 2

150T-6SR HX1512 2 113 625 8 2

175T-6SR HX1709 1 142 730 10 2 3.8 289 325
HX1512 1 109 625

190-6SR HX1816 1 281 1495 10 2 3.8 319 389

Note: MCA - Minimum Circuit Ampacity MFS - Maximum Fuse Size RLA - Running Load Amps
FLA – Full Load Amps LRA - Locked Rotor Amps

- 21 -

TYPICAL WIRING SCHEMATIC

TWO COMPRESSORS UNIT

- 22 -

TYPICAL WIRING SCHEMATIC

- 23 -

TYPICAL WIRING SCHEMATIC

Ω
Ω

- 24 -

TYPICAL WIRING SCHEMATIC

- 25 -

GUIDE SPECIFICATIONS

1. The contractor shall in accordance with the plans, allow condenser to be used as a pump down
furnish and install _____________ Dunham-Bush receiver.)
_______________ packaged liquid chiller(s). The
unit(s) shall be completely factory packaged 5. Evaporator vessels shall all be cleanable shell and
including rotary screw compressor(s), evaporator, tube type with integral finned copper water tubes
condenser, and controller control center. The mechanically expanded into heavy fixed steel tube
packaged chiller shall be factory assembled, sheets. They are to be available in one, two or three
charged and tested with a full operating refrigerant pass design as required on the drawings with
and oil charge. The refrigerant type shall be R134a. Victaulic connections. Flanges or stub out
connections optional. The shell side of the
2. Capacity of each chiller shall be not less than evaporator is to have a single relief valve with
_________________ TR (kW output) cooling provision for refrigerant venting. Evaporators shall
_____________ USgpm (liters/min.) of water from be designed, constructed in accordance with the
__________ °F[°C] to _________ °F[°C]. Power ASME Code for Unfired Pressure Vessels. The
input requirements for the unit(s), incorporating all flooded evaporator shall have a built in distributor
appurtenances necessary for unit operation, for feeding refrigerant evenly under the tube bundle
including but not limited to the control accessories to produce a uniform boiling action and baffle plates
and oil pump or pumps, if required, shall not exceed shall be provided to ensure vapor separation. Water
___________kW input at design conditions. The headers are to be removable for tube cleaning. Vent
unit shall be able to unload to _______% of cooling and drain plugs are to be provided in each head.
(refrigeration) capacity when operating with leaving (All low temperature surfaces shall be factory
chilled water and entering condenser temperature at insulated.)
full load design temperatures. The unit shall be
capable of continuous operation at this point, with 6. The flooded evaporator shall be fitted with an oil
stable compressor operation, without the use of hot recovery system. The oil recovery system will
gas bypass. ensure that the evaporator is operating at peak
efficiency at all times and provide optimal energy
3. Heat transfer surfaces shall be selected to reflect efficiency during extended periods of part load.
the incorporation of a fouling factor of 0.0001 hr.ft². Units without oil recovery systems mounted on the
°F/BTU [0.000018m².°C/W] for the evaporator. evaporator will not be acceptable.
Water pressure drop at design conditions shall not
exceed ____________ feet of water through the 7. The condenser coil is to be constructed of copper
evaporator. tubes and die formed aluminum fins having self-
spacing collars. Fins shall be mechanically bonded
4. The packaged chiller shall be furnished with single- to the tubes. An integral sub-cooling loop shall be
stage direct connected positive displacement rotary incorporated into the coil. Condenser divider baffles
screw compressor(s) as required, of the oil injected shall fully separate each condenser fan section to
type, driven by a 3500 RPM (2900 RPM-50Hz) control the airflow to maintain proper head pressure
motor. Each compressor shall include an integral oil control. The condenser shall be sized for pump
separation system, oil sump and oil filter. The oil down capacity.
temperature shall be controlled during operation to
maintain proper oil temperatures throughout the 8. To maximize energy efficiency, the packaged chiller
lubrication system. An electric oil heater shall be shall be equipped with a flash economizer cycle and
supplied with each compressor to maintain oil modulating refrigerant expansion devices.
temperature during shutdown period. Each Refrigerant vapor from the flash economizer shall
compressor shall have a suction filter, suction be fed back into an intermediate compressor stage,
service valve and a discharge check valve. reducing the enthalpy of the refrigerant and
Compressor capacity control shall be obtained by increasing the net refrigeration effect of the
an electrically initiated, hydraulically actuated slide evaporator.
valve within each compressor housing. (Provide
isolation valves on all connections to compressor to

- 26 -

GUIDE SPECIFICATIONS

9 The fans shall be heavy duty, polypropylene blade, Terminal or PC with communication software
direct drive propeller type. Motors shall be three installed to enable remote monitoring.
phase with internal overloads and are to be 12. The electrical control panel shall be wired to permit
permanently lubricated. fully automatic operation during - initial start-up,
normal operation, and shutdown conditions. The
10. The packaged chiller shall be furnished with a control system shall contain the following control
modulating refrigerant control system to optimize and safety devices:
efficiency and compressor protection. This
refrigerant control system will reduce the flow of MANUAL CONTROLS
efficiency robbing refrigerant vapor in the D Control circuit stop and start switches
condenser from entering the evaporator at reduced D Compressor enable switch
load by directly modulating a motorized refrigerant
valve in the liquid line entering the evaporator. In SAFETY CONTROLS
addition, the refrigerant control system shall D Solid state compressor motor starter overloads
measure the level of liquid refrigerant in the
flooded evaporator and restrict refrigerant flow (3 phase)
entering the evaporator upon a rise in the level, D Low oil level optical sensor
protecting the compressor from liquid slugging. D High condenser pressure
Fixed orifice control systems will not be D Low evaporator pressure
acceptable. (Hot gas bypass shall be factory D Freeze protection
installed for operation below minimum percent of D Chilled water flow loss
unit capacity.) D Under voltage phase failure relay

11. The packaged chiller shall be equipped with AUTOMATIC CONTROLS
controller control. The control shall provide for D Compressor motor increment contactors
compressor loading based on leaving chilled water D Increment start timer
temperature. It shall provide for high and low D Anti-recycle timer
refrigerant pressure protection, low oil level D Oil sump heater interlock relays
protection, evaporator water freeze protection,
sensor error protection, and motor load control REFRIGERANT CONTROLS
(demand limiter) based on amp draw. Anti-recycle D Motorized refrigerant flow control
protection shall also be provided. The controller D Liquid refrigerant level sensor for evaporator
shall have a simple keypad accessed input system D Compressor load and unload solenoid valves
and be complete with a two-line 80 character
alphanumeric display. Input shall be accomplished INDICATOR LIGHTS
through simple menu driven display screens, with D Power on
on-line help available by pressing a help button at D Compressor high oil temperature
anytime during operation. The controller shall D Compressor motor overload
continuously monitor evaporator leaving water D System common alarm
temperature; evaporator and condenser pressure;
compressor amp draw; and refrigerant. The 13. The control system shall be provided with an anti-
controller shall be complete with all hardware and recycle device. The control shall limit compressor
software necessary to enable remote monitoring of starting to a minimum of 15 minutes between
all data through the addition of only a simple, starts.
phone modem and terminal. The controller shall be
complete with an RS232 "local" communications 14. The packaged chiller shall be furnished with unit
port and an RS485 long distance differential mounted reduced inrush starting system for each
communications port. The controller shall also compressor. The starters shall be factory mounted
accept a remote start and stop signal, 0 to 5VDC and wired, with individual circuit breakers on
chilled water temperature reset signal and (0 to multiple compressor units. The unit shall be wired
5VDC compressor current limit reset signal). so that the only field electrical connection to the
packaged chiller shall be to a single three-phase
power terminal.

Optional items in ( )

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Americas Europe Africa

United States of America United Kingdom South Africa

175 South Street, 8 Downley Road, No. 57 Sovereign Drive
West Hartford, Havant, Hampshire, Route 21 Corporate Park
CT 06110, USA England PO9 2JD Irene, Pretoria
South Africa
Tel: 1-860-249 8671 Tel : 44-23-9247 7700
Fax: 1-860-953 3300 Fax:44-23-9245 0396 Tel: 27-12-345 4202
Fax: 27-12-345 4203

China Asia Middle East & North Africa

No. 1 Dunham-Bush Road, Singapore United Arab Emirates
Laishan District,
Yantai, 146B, Paya Lebar Road, Platinum Business Centre
Shandong Province, No. 05-01, Office No. 704
China 264003 ACE Building, P. O. Box 30922,
Singapore 409017 Al Nahda 2nd, Dubai, UAE
Tel: 86-535-658 8999
Fax: 86-535-658 1999 Tel: 65-6842 2012 Tel: 971-4-280 6699
Fax: 65-6842 2013 Fax: 971-4-280 9886

Russia & CIS India Malaysia

Russia 304 Sky Station, Lot 5755-6, Kidamai Industrial Park,
Plot No. 109, Bukit Angkat,
Lot 11, Novinskiy Boulevard, Viman Nagar, 43000 Kajang,
Moscow, Pune 411014, Selangor Darul Ehsan,
121099 Russian Federation India Malaysia

Tel: 7-499-255 6953 Tel: 91-20-4131 4682 Tel: 603-8924 9000
Fax: 7-499-255 6953 Fax: 91-20-4131 4683 Fax: 603-8739 5020

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www.dunham-bush.com

Manufacturer reserves the right to change specifications without prior notice. M-S-0481A-1110