SERIES 20
SINGLE PACKAGE GAS/ELECTRIC UNITS
AND SINGLE PACKAGE AIR
CONDITIONERS
J15, 18, 20 & 25 DJ
15 & 25 NOMINAL TONS
12.00 EER (15 TONS), 11.70 EER (17.5 TONS),
11.3 EER (20 TONS), 10.5 EER (25 TONS)
349687-JTG-A-1007
DESCRIPTION
Johnson Controls Series 20 J**DJ units are convertible single
package high efficiency rooftops. All models have independent dual refrigerant circuits for efficient part load operation.
Although the units are primarily designed for curb mounting
on a roof, they can also be slab-mounted at ground level or
set on steel beams above a finished roof.
All units include:
•Powder Paint finish that meets ASTM-B-117 750 hour
salt spray standards
•Two-stage cooling provided by dual independent
refrigeration circuits with expansion valves, filter-driers, high
and low pressure/loss of charge switches and freezestats
•Scroll compressors
•Two-stage heating provided by dual independent heat
exchangers with aluminized steel tubes, redundant gas
valves, spark ignition with induced draft logic
•Permanently lubricated motors
•Bottom or side air discharge configuration capability
(field convertible)
•Belt Drive Blower Motor with high static drive option
•Constant supply air volume (CV) with optional variable
air volume (VAV)
•Manufactured under the quality standards of ISO9001
A = Std. Drive
B = Std. Drive/Single Input Econo.
C = Std. Drive/Single Input Econo./Power Exhaust
(Downflow Only)
D = Std. Drive/Motorized Damper
E = Std. Drive/Motorized Damper/Barometric Relief
J = Std. Drive/Single Input Econo./Barometric Relief
N = Hi Static Drive
P = Hi Static Drive/Single Input Econo.
Q = Hi Static Drive/Single Input Econo./Power Exhaust
(Downflow Only)
R = Hi Static Drive/Motorized Damper
K = Hi Static Drive/Motorized Damper/Barometric Relief
S = Hi Static Drive/Single Input Econo./Barometric Relief
2 = 208/230-3-60
4 = 460-3-60
5 = 575-3-60
Voltage
Product Style
A = Style A
These four digits will not be assigned until a quote is requested, or an order placed.
SS Drain Pan
Johnson UNT 1126 Controller (N2 protocol), DFS, APS
Johnson Light Commercial Controls System (LCCS) Rtu Controller
Hot Gas Bypass (Standard on VAV, Optional on CV)
Variable Air Volume, VFD
Variable Air Volume, VFD and Manual Bypass
Variable Air Volume, VFD (BAS ready - for customer provided VFD controller)
Variable Air Volume, VFD and Manual Bypass (BAS ready)
Variable Air Volume, VFD Ready (for customer provided, field installed drive)
2" Pleated filters
4" Pleated filters
BAS Ready Economizer (2-10 V.D.C. Actuator without a controller)
Double Wall Construction
Product Generation
1 = First Generation
2 = Second Generation
Standard Cabinet
AA = None
AB = Phase Monitor
AC = Coil Guard
AD = Dirty Filter Switch
AE = Phase Monitor & Coil Guard
AF = Phase Monitor & Dirty Filter Switch
AG = Coil Guard & Dirty Filter Switch
AH = Phase Monitor, Coil Guard & Dirty Filter Switch
RC = Coil Guard & American Flag
TA = Technicoat Condenser Coil
TJ = Technicoat Evaporator Coil
TS = Technicoat Evaporator & Condenser Coils
ZZ = If desired option combination is not listed above, ZZ will be assigned and configuration options will be
located in digits 15-18.
Installation Options
A = No Options Installed
B = Option 1
C = Option 2
D = Options 1 & 2
E = Option 3
F = Option 4
G = Options 1 & 3
H = Options 1 & 4
J = Options 1, 2 & 3
K = Options 1, 2, & 4
L = Options 1,3 & 4
M = Options 1, 2, 3, & 4
N = Options 2 & 3
P = Options 2 & 4
Q = Options 2, 3, & 4
R = Options 3 & 4
S = Option 5
T = Options 1 & 5
U = Options 1, 3, & 5
V = Options 1, 4, & 5
W = Options 1, 3, 4, & 5
X = Options 3 & 5
Y = Options 4 & 5
Z = Options 3, 4 & 5
Configuration Options (not required for all units)
For valid combinations of the above; see the equipment price pages or
the Unitary Sales Tool program; all combinations are not available
Additional Options
Hinged Filter Door & Tool Free Access Cabinet
BA = Hinged Filter Door & Tool Free Access Panels
BB = Phase Monitor, Hinged Filter Door & Tool Free
All Series 20 J**DJ models are available with a wide variety
of factory-mounted options such as stainless steel heat
exchangers, phase monitor, dirty filter switch, and coil guard
to make them suitable for almost every application.
All units are self-contained and assembled on full perimeter
base rails with holes in the four corners for overhead rigging.
Every unit is completely piped, wired, charged and tested at
the factory to simplify the field installation and to provide
years of dependable operation.
All models (including those with an economizer) are suitable
for either bottom or horizontal duct connections. Models with
factory installed power exhaust are suitable for bottom
duct connections only. For bottom duct, you remove the
sheet metal panels from the supply and return air openings
through the base of the unit. For horizontal duct, you replace
the supply and return air panels on the rear of the unit with a
side duct flange accessory.
All models are available with these “factory mounted” outdoor
air damper options:
•Single enthalpy economizer with or without power
exhaust
•BAS-ready economizer with or without power exhaust
•Motorized outdoor air damper
•Barometric Relief Damper
A fixed outdoor air intake assembly will be shipped in the
return air compartment of all units ordered without an economizer or motorized outdoor air damper option. The assembly
includes a rain hood with a damper that can be set for 10, 15
or 25% outdoor air. With bottom duct connections, the intake
damper assembly should be mounted over the opening in the
return air panel. With horizontal ductwork, it should be
mounted on the return air duct.
All supply air blowers are equipped with a b el t dri ve th at can
be adjusted to meet the exact requirements of the job. A high
static drive option is available for applications with a higher
CFM and/or static pressure requirement. A variable air volume (VAV) option using a variable frequency drive is available
for applications requiring a consta nt supply duct pressure. A
differential pressure transducer is used to monitor supply duct
static pressure and return a speed reference signal to the VFD
to control the output of the indoor blower motor.
All compressors include scroll compressors and internal pressure relief. Every refrigerant circuit includes an expansion
valve, a liquid line filter-drier, a discharge line high pressure
switch and a suction line with a freezestat and low pressure/
loss of charge switch to protect all system components. A hot
gas bypass option, consisting of an adjustable compressor
discharge bypass valve, is available for low cooling load
applications.
•Advanced Controls - Unit control boards have standardized a number of features previously available only
as options or by utilizing additional controls.
•Low Ambient - An integrated low-ambient control
allows all units to operate in the cooling mode down
to 0ºF outdoor ambient without additional assistance. Optionally, the control board can be programmed to lockout the compressors when the
outdoor air temperature is low or when free cooling
is available.
•Anti-Short Cycle Protection - To aid compressor
life, an anti-short cycle delay is incorporated into the
standard controls. Compressor reliability is further
ensured by programmable minimum run times. For
testing, the anti short cycle delay can be temporarily
overridden with the push of a button.
•Lead-Lag - An integrated Lead-Lag option allows
equal run time hours on all compressors, thereby
extending the life of all compressors. This option is
selectable on the unit control board.
•Fan Delays - Fan on and fan off delays are fully programmable. Furthermore, the heating and cooling
fan delay times are independent of one another. All
units are programmed with default values based
upon their configuration of cooling and heat.
•Safety Monitoring - The control board monitors the
high and low-pressure switches, the freezestats, the
gas valve, if applicable, and the temperature limit
switch on gas and electric heat units. The unit control board will alarm on ignition failures, compressor
lockouts and repeated limit switch trips.
Nuisance Trip Protection and Strikes - To prevent
•
nuisance trouble calls, the control board uses a
“three times, you’re out” philosophy. The high and
low-pressure switches and the freezestats must trip
three times within two hours before the unit control
board will lock out the associated compressor.
•On Board Diagnostics - Each alarm will energize a
trouble light on the thermostat, if so equipped, and
flash an alarm code on the control board LED. Each
high and low-pressure switch alarm as well as each
freezestat alarm has its own flash code. The control
board saves the five most recent alarms in memory,
and these alarms can be reviewed at any time.
Alarms and programmed values are retained
through the loss of power.
All units have long lasting powder paint cabinets with 750
hour salt spray test approval under ASTM-B117 procedures.
All models are CSA approved.
•Warranty - All models include a one-year limited parts
warranty on the complete unit. Compressors and electric
heater elements carry a five-year warranty. Gas heat
exchangers carry a 10-year parts warranty.
•Gas Heat Operation - All gas heat units are built with
two heating sections for two equal stages of capacity
control. Each section includes a durable heat exchanger
4Johnson Controls Unitary Products
349687-JTG-A-1007
UNIT
FIGURE 1 - UNIT CUTAWAY
with aluminized steel or optional stainless steel tubes, a
redundant gas valve, spark ignition, power venting, an
ignition module for 100% shut-off and all of the safety
controls required to meet the latest ANSI standards.
The gas supply piping can be routed into the heating
compartment through a hole in the base pan of the unit
or through a knockout in the piping panel on the front of
the unit.
•Electric Heat Operation - All electric heat models (factory installed only) are wired for a single power source
and include a bank of nickel chromium elements
mounted at the discharge of the supply air blower to provide a high velocity and uniform distribution of air across
the heating elements. Every element is fully protected
against excessive current and temperature by fuses and
two thermal limit switches.
The power supply wiring can be routed into the control
box through a threaded pipe connection in the base pan
of the unit or through a knockout in the wiring panel on
the front of the unit.
FACTORY-INSTALLED OPTIONS
•SINGLE INPUT ELECTRONIC ENTHALPY ECONOMIZERS - Includes a slide-in / plug-in damper assembly
with fully modulating spring-return motor actuator capa-
ble of introducing up to 100% outdoor air with nominal
1% leakage type dampers.
The enthalpy system contains one sensor that monitors
the outdoor air and determines when the air is cool
enough and dry enough to provide free cooling.
The rainhood is painted to match the basic unit and must
be field-assembled before installing.
•BAS-READY ECONOMIZER - Includes a slide-in / plugin damper assembly with fully modulating spring-return
motor actuator with zero to 95-degree rotation capable of
introducing up to 100% outdoor air with nominal 1% leakage type dampers.
Actuator requires 2-10 VDC input from an external
source, such as a field-installed or factory-installed BAS
controller. BAS-ready actuators have an adjustable auxiliary end-switch for optional power exhaust control.
For units with optional VAV control, a factory-installed,
dry bulb sensor determines if outdoor air temperature is
low enough to provide free-cooling operation. (Fieldinstalled humidity sensors for either outdoor air or outdoor & return air streams are available for single
enthalpy and differential enthalpy configurations, respectively).
The rainhood is painted to match the basic unit and must
be field-assembled before installing.
Johnson Controls Unitary Products5
349687-JTG-A-1007
•POWER EXHAUST - Our economizer options are available with power exhaust. Whenever the outdoor air
intake dampers are opened for free cooling, the exhaust
fan will be energized to prevent the conditioned space
from being over-pressurized during economizer operation. BAS-ready economizer actuators have an adjustable auxiliary end-switch to provide a range of damper
positions available to energize power exhaust.
The exhaust fan, motor and controls are installed and
wired at the factory. The rain hood must be assembled
and installed in the fiel d .
The power exhaust option can only be used on bottom duct configurations.
•MOTORIZED OUTDOOR AIR INTAKE DAMPER -
Includes a slide-in / plug-in damper assembly with a 2position, spring return motor actuator which opens to a
pre-set position whenever the supply air blower is operating and will drive fully closed when the blower unit
shuts down.
The rain hood is painted to match the basic unit and
must be field assembled before installing.
•BAROMETRIC RELIEF DAMPER - This damper option
can be used to relieve internal building air pressure on
units with an economizer without power exhaust. This
accessory includes a rain hood, a bird screen and a fully
assembled damper. With bottom duct connections, the
damper should be mounted over the opening in the
return air panel. With horizontal ductwork, the accessory
should be mounted on the return air duct.
•PHENOLIC COATED EVAPORATOR AND CON-DENSER COILS - Special coating process that utilizes
Technicoat 10-1" processes. Coating is applied by total
immersion of the complete coil for maximum protection.
•ELECTRIC HEA T ERS wired for single point power supply. These nickel chromium heater elements are provided with limit and automatic reset capability to prevent
operation at excessive temperatures.
•VARIABLE AIR VOLUME (VAV) - A factory-installed
variable frequency drive (VFD), mounted in the Blower
Access compartment, is used to control the speed of the
indoor blower motor in order to maintain a constant static
pressure in the supply duct. A pressure transducer and
VAV control board are mounted inside the control box.
The drive comes completely wired and pre-programmed
from the factory.
An optional, factory-installed manual bypass switch
available with factory-installed VFD can be found in the
Blower Motor Access compartment. The switch can be
used to either route power to the VFD for modulating
control of the blower motor, to bypass the drive and operate the motor at full speed, or to power the drive (and not
the motor) for diagnostic purposes.
Due to space limitations, VAV is not available with any of
the factory-installed BAS options described below, but is
available with ‘BAS-ready’ models. Terminal blocks are
provided in the control box for field wiring of the customer-installed BAS.
A ‘VFD-ready’ option provides the provisions for a customer-installed drive. The unit comes with a mounting
bracket installed in the Blower Access compartment
which may accommodate other vendor’s drives depending on their size. In order to utilize the unit’s mounting
bracket, the maximum recommended drive dimensions
are as follows:
For 5-hp motor applications........................13” H x 6” W x 7” D
For 7.5 thru 15-hp motor applications.........13” H x 8” W x 8” D
If the drive will not fit in the allotted space, then it will
have to be mounted elsewhere; either within the building
on a perpendicular wall which is not subjected to excessive temperature, vibration, humidity, dust, corrosive
gas, explosive gas, etc., or within an appropriate enclosure rated for outside installation to safeguard against
moisture, dust and excessive heat.
A terminal block located in the control box is provided for
field connection of the VFD controls.
•HOT GAS BYPASS - To allow for low cooling load operation, a direct-acting pressure-modulating bypass control
valve installed on the system #1 discharge line is used to
divert high temperature, high pressure refrigerant around
the TXV in order to maintain a desired minimum evaporator pressure. HGBP is standard on all units with VAV
and optional with CV units.
•FILTER OPTIONS - Standard units are shipped with 2”
throw-away filters installed. 2” pleated and 4” pleated filters are offered as a factory installed option.
•CONVENIENCE OUTLET - This 110 volt outlet can be
“powered” by the unit with a stepdown transformer or
you may order the unit with a “non-powered” convenience outlet that can be wired in the field.
•DISCONNECT SWITCH - For gas heat units and cooling
units with electric heat, a HACR breaker sized to the unit
is provided. For cooling only units, a switch sized to the
largest electric heat available for the particular unit is
provided. Factory installed option only.
•DOUBLE WALL CONSTRUCTION - Optional double
wall construction is available to provide smooth inner
surfaces for easy and effective cleaning to reduce risk of
dirt and bacterial accumulation. Fiberglass insulation is
sandwiched between heavy gauge steel sheets to form a
durable, rigid casing to withstand higher working pressures and impact forces. The heavy-duty construction
provides excellent acoustic and thermal insulation and
eliminates erosion of insulation material and contamination of the air stream.
6Johnson Controls Unitary Products
349687-JTG-A-1007
•SMOKE DETECTORS - (supply air & return air) The
smoke detectors stop operation of the unit by interrupting
power to the control board if smoke is detected within the
air compartment.
Factory installed smoke detectors in the return air
may be subjected to freezing temperatures during
“off” times due to outside air infiltration. These
smoke detectors have an operation limit of 32°F to
131°F. Smoke detectors installed in areas that
could be outside those limitations will have to be
moved to prevent having false alarms.
•COIL GUARD - Customers can purchase a coil guard kit
to protect the condenser coil from damage. This is not a
hail guard kit.
•STAINLESS STEEL HEAT EXCHANGER - For applica-
tions in corrosive environments, this option provides a
full stainless steel heat exchanger assembly.
•ST AINLESS STEEL DRAIN PAN - An optional rust-proof
stainless steel drain pan is available to provide years of
trouble-free operation in corrosive environments.
•PHASE MONITORS - Designed to prevent unit damage.
The phase monitor will shut the unit down in an out-ofphase condition.
•HIGH ST ATIC DRIVE - Includes a belt and blower pulley
upgrade to enhance blower performance.
•DIRTY FILTER SWITCH - This kit includes a differential
pressure switch that energizes the fault light on the unit
thermostat, indicating that there is an abnormally high
pressure drop across the filters. Factory installed option
or field installed accessory.
•HINGED FIL TER DOOR/”TOOL FREE” BLOWER AND
ACCESS PANELS (not hinged) - This option allows for
easy access and maintenance.
NOTE:Knobs are shipped separately within the unit to
prevent shipping damage. These must be field
installed for tool free operation.
•HINGED/"TOOL FREE" BLOWER, BLOWER MOTOR, FIL TER AND ELECTRIC ACCESS PANELS - This
option allows for complete hinged and tool free access to
the unit's blower, blower motor , filters and electrical panel
sections.
CONTROL OPTIONS
•Johnson Light Commercial System (LCCS) - Provides
rooftop system integration for LCCS single zone,
change-over bypass and VAV systems.
•Johnson UNT 1126 Rooftop Controller - N2 protocol
with air proving and dirty filter sensors. Hardware contains generic application logic; field engineering and/or
modification may be required.
FIELD-INSTALLED ACCESSORIES
•SINGLE INPUT ELECTRONIC ENTHALPY ECONOMIZERS - Includes a slide-in / plug-in damper assembly
with fully modulating spring-return motor actuator capable of introducing up to 100% outdoor air with nominal
1% leakage type dampers.
The enthalpy system contains one sensor that monitors
the outdoor air and determines when the air is cool
enough and dry enough to provide free cooling.
The rainhood is painted to match the basic unit and must
be field-assembled before installing.
•MOTORIZED OUTDOOR AIR INTAKE DAMPER -
Includes a slide-in / plug-in damper assembly with a 2position, spring return motor actuator which opens to
some pre-set position whenever the supply air blower is
operating and will drive fully closed when the blower unit
shuts down.
The rain hood is painted to match the basic unit and
must be field assembled before installing.
•ROOF CURBS - Fourteen-inch high roof curbs provide a
water-tight seal between the unit and the finished roof.
These full perimeter curbs meet the requirements of the
National Roofing Contractors Association (NRCA) and
are shipped knocked-down for field assembly.
They're designed to fit inside the base rails of the unit
and include both a wood nailing strip and duct hanger
supports.
•HIGH ALTITUDE NATURAL GAS - Burner orifices and
pilot orifices are provided for proper furnace operation at
altitudes up to 6,000 feet.
•PROPANE - Burner orifices, pilot orifices and gas valve
parts are provided to convert a natural gas furnace to
propane.
•HIGH ALTITUDE PROPANE - Burner orifices and pilot
orifices are provided for proper furnace operation at altitudes up to 6,000 feet. This accessory supplements the
basic propane conversion kit.
•SIDE DUCT FLANGES - One-inch flanges replace the
supply and return air panels on the rear of the unit to
accommodate horizontal duct connections. These
flanges can also be used individually for bottom supply/
horizontal return or horizontal supply/bottom return. They
cannot be used on units with power exhaust.
•BAROMETRIC RELIEF DAMPER - This damper accessory can be used to relieve internal building air pressure
on units with an economizer without power exhaust. This
Johnson Controls Unitary Products7
349687-JTG-A-1007
accessory includes a rain hood, a bird screen and a fully
assembled damper. With bottom duct connections, the
damper should be mounted over the opening in the
return air panel. With horizontal ductwork, the accessory
should be mounted on the return air duct.
•HIGH STATIC DRIVE - A smaller blower pulley and a
shorter belt increase the speed of the supply air blower
for applications with a higher CFM and/or static pressure
requirements.
•ENTHALPY ACCESSORY CONTROL KIT - This kit
contains the required components to convert a single
enthalpy economizer to dual enthalpy.
•BURGLAR BARS - Mount in the supply and return
openings to prevent entry into the duct work.
•FLUE EXHAUST EXTENSION KIT - In locations with
wind or weather conditions which may interfere with
proper exhausting of furnace combustion products, this
kit can be installed to prevent the flue exhaust from
entering nearby fresh air intakes.
•WOOD SKID - Allows unit to be handled with 90” forks.
•CO
SENSOR - Senses CO2 levels and automatically
2
overrides the economizer when levels rise above the
present limits.
•COIL GUARD - Customers can purchase a coil guard kit
to protect the condenser coil from damage. This is not a
hail guard kit.
•PHASE MONITORS - Designed to prevent unit damage.
The phase monitor will shut the unit down in an out-ofphase condition.
These values have been accessed using a model of sound propagation from a point source into the hemispheric\free field. The
dBA values provided are to be used for reference only. Calculation of dBA values cover matters of system design and the fan
manufacture has no way of knowing the details of each system. This constitutes and expectation to any specification or guarantee requiring a dBA value or sound data in any other form than sound power level ratings.
ment certification program which is based on ARI Standard 340/360.
2.
EER = Energy Efficiency Ratio at full load - the cooling
capacity in Btu’s per hour (Btuh) divided by the power
input in watts, expressed in Btuh per watt (Btuh/watt).
NOTE: All gas units are two-stage heating.
First stage is 50% of total.
S.S.E. = Steady State Efficiency (80%) - output divided by input.
For units with VFD and electric or gas heat, the
speed of the indoor blower motor continues to
be controlled by duct static pressure via the
VAV control board.
If there are VAV boxes present in the duct system, the boxes must be driven to the full-open
position using a customer-supplied power
source to assure adequate airflow across electric heating elements or gas heat exchanger
tubes.
Johnson Controls Unitary Products9
TABLE 4: COOLING CAPACITIES FOR J15DJ
Air on Evaporator Coil
1
Total
Input
(kW)
2
8683807774716886838077747168
CFM
4500
5250
6000
6600
7200
4500
5250
6000
6600
7200
4500
5250
6000
6600
7200
1.
The capacities are gross ratings. For net capacity, deduct air blower motor, MBh = 3.415 x kW. Refer to the appropriate Blower
Performance table for the kW of the supply air blower motor.
2.
These ratings include the condenser fan motors (total 1 kW) and the compressor motors but not the supply air blower motor.
The capacities are gross ratings. For net capacity, deduct air blower motor, MBh = 3.415 x kW. Refer to the appropriate Blower
Performance table for the kW of the supply air blower motor.
2.
These ratings include the condenser fan motors (total 1 kW) and the compressor motors but not the supply air blower motor.
The capacities are gross ratings. For net capacity, deduct air blower motor, MBh = 3.415 x kW. Refer to the appropriate Blower
Performance table for the kW of the supply air blower motor.
2.
These ratings include the condenser fan motors (total 1 kW) and the compressor motors but not the supply air blower motor.
The capacities are gross ratings. For net capacity, deduct air blower motor, MBh = 3.415 x kW. Refer to the appropriate Blower
Performance table for the kW of the supply air blower motor.
2.
These ratings include the condenser fan motors (total 1 kW) and the compressor motors but not the supply air blower motor.
CFM, STATIC PRESSURE, AND POWER - ALTITUDE AND TEMPERATURE CORRECTIONS
The information below should be used to assist in application
of product when being applied at altitudes at or exceeding
1000 feet above sea level.
order to use the indoor blower tables for high altitude applications, certain corrections are necessary.
A centrifugal fan is a "constant volume" device. This means
that, if the rpm remains constant, the CFM delivered is the
same regardless of the density of the air. However, since the
air at high altitude is less dense, less static pressure will be
The air flow rates listed in the standard blower performance
tables are based on standard air at sea level. As the altitude
or temperature increases, the density of air decreases. In
generated and less power will be required than a similar
application at sea level. Air density correction factors are
shown in Table 8 and Figure 2.
The examples below will assist in determining the airflow performance of the product at altitude.
Example 1: What are the corrected CFM, static pressure,
and BHP at an elevation of 5,000 ft. if the blower performance
data is 6,000 CFM, 1.5 IWC and 4.0 BHP?
Solution: At an elevation of 5,000 ft the indoor blower will still
deliver 6,000 CFM if the rpm is unchanged. However, Table
8 must be used to determine the static pressure and BHP.
Since no temperature data is given, we will assume an air
temperature of 70°F. Table 8 shows the correction factor to
be 0.832.
Corrected static pressure = 1.5 x 0.832 = 1.248 IWC
Corrected BHP = 4.0 x 0.832 = 3.328
ALTITUDE (FEET)
blower tables to select the blower speed and the BHP
requirement.
Solution: As in the example above, no temperature information is given so 70°F is assumed.
The 1.5" static pressure given is at an elevation of 5,000 ft.
The first step is to convert this static pressure to equivalent
sea level conditions.
Sea level static pressure = 1.5 / .832 = 1.80"
Enter the blower table at 6000 sCFM and static pressure of
1.8". The rpm listed will be the same rpm needed at 5,000 ft.
Suppose that the corresponding BHP listed in the table is 3.2.
This value must be corrected for elevation.
Example 2: A system, located at 5,000 feet of elevation, is to
BHP at 5,000 ft = 3.2 x .832 = 2.66
deliver 6,000 CFM at a static pressure of 1.5". Use the unit
14Johnson Controls Unitary Products
349687-JTG-A-1007
FIGURE 2 - ALTITUDE/TEMPERATURE CONVERSION FACTOR
Johnson Controls Unitary Products15
349687-JTG-A-1007
TABLE 9: SUPPLY AIR BLOWER PERFORMANCE (15 TON) - COOLING ONLY
NOTES: 1.Blower performance includes fixed outdoor air, 2” T/A filters, a dry evaporator coil and no electric heat.
MOTOR
PULLEY
(TURNS
OPEN)*
2.Refer to T able 13 for additional static resistances.
ESP = External Static Pressure available for the supply and return air duct system. All internal unit resistances have been deducted from the total
static pressure of the blower.
* Do NOT
** Factory setting.
close the pulley below 1 turn open.
45005250600067507200
ESPBHPKWESPBHPKWESPBHPKWESPBHPKWESPBHPKW
CFM
16Johnson Controls Unitary Products
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TABLE 10: SUPPLY AIR BLOWER PERFORMANCE (17.5 TON) - COOLING ONLY
NOTES: 1.Blower performance includes fixed outdoor air, 2” T/A filters, a dry evaporator coil and no electric heat.
MOTOR
PULLEY
(TURNS
OPEN)*
2.Refer to T able 13 for additional static resistances.
ESP = External Static Pressure available for the supply and return air duct system. All internal unit resistances have been deducted from the total
static pressure of the blower.
* Do NOT
** Factory setting.
close the pulley below 1 turn open.
60007000800090009400
ESPBHPKWESPBHPKWESPBHPKWESPBHPKWESPBHPKW
CFM
18Johnson Controls Unitary Products
349687-JTG-A-1007
TABLE 12: SUPPLY AIR BLOWER PERFORMANCE (15 TON) - GAS HEAT
NOTES: 1.Blower performance includes a gas-fired heat exchanger, fixed outdoor air, two-inch T/A filters and a dry evaporat or coil.
2.Refer to the additional Static Resistances tabl e.
ESP = External Static Pressure available for the supply and return air duct system. All internal unit resistances have been deducted from the total
static pressure of the blower.
* Do NOT
** Factory setting.
close the pulley below 1 turn open.
Johnson Controls Unitary Products19
349687-JTG-A-1007
TABLE 13: SUPPLY AIR BLOWER PERFORMANCE (17.5 TON) - GAS HEAT
NOTES: 1.Blower performance includes a gas-fired heat exchanger, fixed outdoor air, two-inch T/A filters and a dry evaporator coil.
2.Refer to the additional Static Resistances tabl e.
ESP = External Static Pressure available for the supply and return air duct system. All internal unit resistances have been deducted from the total
static pressure of the blower.
* Do NOT
** Factory setting.
close the pulley below 1 turn open.
20Johnson Controls Unitary Products
349687-JTG-A-1007
TABLE 14: SUPPLY AIR BLOWER PERFORMANCE (20 TON) - GAS HEAT
NOTES: 1.Blower performance includes a gas-fired heat exchanger, fixed outdoor air, two-inch T/A filters and a dry evaporat or coil.
2.Refer to the additional Static Resistances tabl e.
ESP = External Static Pressure available for the supply and return air duct system. All internal unit resistances have been deducted from the total
static pressure of the blower.
* Do NOT
** Factory setting.
close the pulley below 1 turn open.
Johnson Controls Unitary Products21
349687-JTG-A-1007
TABLE 15: SUPPLY AIR BLOWER PERFORMANCE (25 TON) - GAS HEAT
NOTES: 1.Blower performance includes a gas-fired heat exchanger, fixed outdoor air, two-inch T/A filters and a dry evaporator coil.
2.Refer to the additional Static Resistances tabl e.
ESP = External Static Pressure available for the supply and return air duct system. All internal unit resistances have been deducted from the total
static pressure of the blower.
* Do NOT
** Factory setting.
close the pulley below 1 turn open.
22Johnson Controls Unitary Products
349687-JTG-A-1007
TABLE 16: BLOWER MOTOR AND DRIVE DATA
1
MODEL
SIZE
Standard 850/1065
15 TON
Standard 870/1025
17.5 &
20 TON
Standard 975/1165
25 TON
1.
All motors have a nominal speed of 1800 RPM, a 1.15 service factor and a solid base. They can operate to the limit of their service factor because
they are located in the moving air, upstream of any heating device.
Deduct these resistance values from the available external static pressures shown in th e re sp ec ti ve Bl o w er Pe r fo r m a nc e Table (See Note 2 for
exception.)
2.
Since the resistance to air flow will be less for horizontal duct connections than for bottom duct connections, add these pressures to the ESP values
on the respective unit’s blower performance table.
0.10.20.30.20.30.50.20.30.50.30.50.6
TABLE 18: POWER EXHAUST PERFORMANCE
MOTOR
1
SPEED
2
HIGH
MEDIUM
LOW
1.
Power exhaust motor is a 3/4 HP, PSC type with sleeve bearings, a 48 frame and inherent protection.
Utilization Range “A” in accordance with ARI Standard
110.
208/230-3-60
460-3-60
575-3-60
VOLTAGE
MIN.MAX.
187253
414506
518630
TABLE 22: PHYSICAL DATA
MODELSJ15DJJ18DJJ20DJJ25DJ
EVAPORATOR
BLOWER
EVAPORATOR
COIL
CONDENSER FAN
(Four Per Unit)
CONDENSER
COIL
COMPRESSOR
(Qty. Per Unit)
FILTERS
CHARGE
OPERATING
WEIGHTS
(LBS.)
CENTRIFUGAL BLOWER (Dia. x Wd.)15x1518x1518x1518x15
FAN MOTOR HP5.07.57.515
ROWS DEEP4
FINS PER INCH13.5
FACE AREA (Sq. Ft.)25
PROPELLER DIA. (In.) (Each)24243030
FAN MOTOR HP (Each)1/31/33/43/4
NOM. CFM TOTAL (Each)4,0004,0005,0005,000
ROWS DEEP2
FINS PER INCH20
FACE AREA (Sq. Ft.)63.8
SCROLL2
QUANTITY PER UNIT (12" X 24" X 2"12
TOTAL FACE AREA (Sq. Ft.)24
REFRIGERANT
22 (Lb./Oz.)
BASIC UNIT
OPTIONS
ACCESSORIES
1
SYSTEM No.123/024/023/823/8
SYSTEM No. 223/824/023/823/8
COOLING ONLY2260254025602660
GAS / ELECTRIC
DOUBLE WALL260
ECONOMIZER160
ECONOMIZER WITH
POWER EXHAUST
MOTORIZED DAMPER150
ELECTRIC HEATER
HOT GAS BYPASS10
SUPPLY FAN VFDSee Table 23
ROOF CURB185
BAROMETRIC DAMPER45
ECONOMIZER / MOTORIZED
DAMPER RAIN HOOD
ECONOMIZER / POWER
EXHAUST RAIN HOOD
WOOD SKID220
Terminal block 1TB- located on relay board in 24-volt section of the unit control box.
3
Second stage heating is not required on units with a single stage electric heater.
4
Terminals A1 and A2 provide a relay output to close the outdoor economizer dampers
2THO4702224 IF USED
when the thermostat switches to the set-back position.
NOTE: Fans switch must be in "ON" position for minimum ventilation during heater operation.
3
4
UNIT TERMINAL
BLOCK 1 TB
4
2
R
Y1
Y2
W1
W2
G
B
X
24 VOLT
A1
TRANSFORMER
A2
TABLE 24: ELECTRIC HEAT CORRECTION
FACTORS
NOMINAL VOLTAGEVOLTAGE
208
240
480
600
COOLING / HEATING (24 VOLT THERMOSTAT)
THERMOSTAT
TERMINALS
ADD
JUMPER
1
24 Volt Thermostat 2TH04701024 or 2TH04701524
(with Subbase 2TB04700324).
2
Terminal strip 1TB - located on relay board in 24-volt section
of the unit control box.
3
Second stage heating is not required on units with a single stage
electric heater.
1
RH
RC
Y1
Y2
W1
W2
G
2081.00
2300.92
4600.92
5750.92
UNIT TERMINAL
BLOCK 1TB
3
R
Y1
Y2
W1
W2
G
B
X
A1
A2
Y3
kW CAP. MULTI-
2
24 VOLT
TRANSFORMER
PLIER
POWER WIRING
LINE VOLTAGE
TERMINAL
BLOCK 2TB
IN CONTROL BOX
GROUND LUG
L1
L2
L3
Refer to the
ELECTRICAL DATA
tables to size the
power wiring, the
fuses and the
disconnect switch.
FIGURE 3 - TYPICAL J**DJ FIELD WIRING DIAGRAM
Johnson Controls Unitary Products29
BLOWER MOTOR
ACCESS (Location
BLOWER
COMPARTMENT
ACCESS
(Auxiliary)
of Optional VFD Bypass)
DOT PLUG
(For pressure
drop reading)
GAS OR ELECTRIC
HEAT
ACCESS
VENT AIR
OUTLET
HOODS
COMBUSTION
AIR INLET HOOD
UNIT BASE RAILS
Shown separately to illustrate
Bottom Duct openings. Power
and Gas Piping Connection
location.
NOTE:
For curb mounted units, refer to the curb hanger
dimensions of the curb for proper size of the
supply and return air duct connections.
52-5/8
BLOWER ACCESS
(Location of
Optional VFD)
(C) GAS
SUPPLY
ENTRY
136-1/4
CONTROL BOX
ACCESS
(D)
GAS SUPPLY
ENTRY
35
35-1/4
11-1/8
7-1/8
46-5/8
2-3/4
5-7/8
33
12-1/2
21.00
6-3/8
9-3/4
46-5/8
RETURN
AIR
21-1/2
5
ECONOMIZER / MOTORIZED DAMPER
FIXED OUTDOOR INTAKE AIR AND
POWER EXHAUST RAIN HOODS
(See detail Y)
180-19/32
11-1/2
BOTTOM SUPPLY
AND RETURN
AIR OPENINGS
(See Note)
SUPPLY
AIR
8-1/8
9-1/4
9-3/4
COMPRESSOR ACCESS
92
(B) POWER
WIRING
ENTRY
(B) POWER WIRING
ENTRY
(A) CONTROL WIRING
ENTRY
(A) CONTROL WIRING
ENTRY
DISCONNECT
SWITCH
LOCATION
3-3/4
349687-JTG-A-1007
COIL
GUARD
KIT
CONDENSER
COILS
All dimensions are in inches. They are
subject to change without notice.
Certified dimensions will be provided
upon request.
FIGURE 4 - FRONT VIEW DIMENSIONS
TABLE 25: UTILITIES ENTRY DATA
HOLE
30Johnson Controls Unitary Products
OPENING SIZE
(DIA.)
A
B
C
D
1.
2.
NOTE:
1-1/8” KO
3/4” NPS (Fem.)Bottom
3-5/8” KO
3” NPS (Fem.)Bottom
2-3/8” KO
1-11/16” Hole
One-inch gas piping NPT required.
Opening in the bottom of the unit can be located by the slice in
the insulation.
All entry holes should be field sealed to prevent rain
Control Wiring
Power Wiring
USED FOR
Gas Piping (Front)
Gas Piping (Bottom)
water entry into the building.
Side
Side
1
1, 2
349687-JTG-A-1007
COMPRESSOR
ACCESS
SUPPLY AIR
ACCESS
Dimensions listed are for side
duct flange openings; see
Field Accessories for Side
Duct Flange Kit.
FIGURE 5 - REAR VIEW DIMENSIONS
40-3/8"
RETURN AIR
ACCESS
REAR
VIEW
SUPPLY
AIR
18-5/8"
5-1/8"
RETURN
AIR
27-3/4"
OUTDOOR
AIR
39-5/8"
40-1/2"
OUTDOOR AIR
COMPARTMENT
ACCESS
EVAPORATOR
SECTION
DOT PLUG
(For pressure
drop reading)
FILTER
ACCESS
1" NPT FEMALE
COND. DRAIN
CONNECTION
NOTE:Units are shipped with the bottom duct openings
covered. An accessory flange kit is available for
connecting side ducts.
For bottom duct applications:
1.Remove the side panels from the supply and return air
compartments to gain access to the bottom supply and
return air duct covers.
2.Remove and discard the bottom duct covers. Duct
openings are closed with sheet metal covers except
when the unit includes a power exhaust option. The
covering consists of a heavy black paper composition.
3.Replace the side supply and return air compartment
panels.
For side duct applications:
1.Replace the side panels on the supply and return air
compartments with the side duct flange accessory kit
panels.
2.Connect ductwork to the flanges on those panels.
Johnson Controls Unitary Products31
349687-JTG-A-1007
TABLE 26: MINIMUM CLEARANCES
LOCATION
CLEARANCE
Front
Rear
Left Side (Filter Access)
24” (Less Economizer)
49” (With Economizer)
24” (Less Economizer)
36” (With Economizer)
Right Side (Cond. Coil)
Below Unit
Above Unit
1
2
72” With 36” Maximum
Horizontal Overhang (For
Condenser Air Discharge)
1.
Units may be installed on combustible floors made from wood or
class A, B, or C roof covering material.
2.
Units must be installed outdoors. Overhanging structures or
shrubs should not obstruct condenser air discharge outlet.
3. If economizer is factory installed, the unassembled rain hood
must be removed from its ride along position in front of evaporator coil, or in the outdoor air compartment, prior to final installation.
ECONOMIZER
MOTORIZED
SUPPLY AIR
COMPARTMENT
POWER EXHAUST
RAIN HOOD
(on Return Air Compartment)
DAMPER
RAIN HOOD
(on Outdoor Air Compartment)
36”
36”
0”
NOTE: ELEC / ELEC Models: Units and ductwork are
approved for zero clearance to combustible material
when equipped with electric heaters.
GAS / ELEC Models
: A 1” clearance must be
provided between any combustible material and the
3
supply air ductwork for a distance of 3 feet from the
unit.
The products of combustion must not be allowed to
accumulate within a confined space and recirculate.
Locate unit so that the vent air outlet hood is at least:
• Three (3) feet above any force air inlet located
within 10 horizontal feet (excluding those integral to
the unit).
• Four (4) feet below, four horizontal feet from, or one
foot above any door or gravity air inlet into the
building.
• Four (4) feet from electric and gas meters,
regulators and relief equipment.
ECONOMIZER / MOTORIZED DAMPER
AND POWER EXHAUST RAIN HOODS
36-5/8”
16-1/8”
5”
28-3/16”
REAR VIEW
DETAIL “Y”
UNIT WITH RAIN HOODS
FIGURE 6 - UNIT DIMENSIONS J15, 18, 20 & 25 DJ (RAINHOOD)
FIXED
OUTDOOR AIR
INTAKE HOOD
(located on
Return Air
Compartment)
Note: These weights are with economizer and high option heat (gas or electric).
34Johnson Controls Unitary Products
349687-JTG-A-1007
25-1/4"
FIGURE 10 - UNIT ROOF CURB DIMENSIONS
FIGURE 11 - ROOF CURB DUCT OPENINGS
DIMENSION
1.The 2” space between the ducts allows for “jumping” an
existing roof joist.
2.The 58-1/2” overall dimension of the ducts allows ductwork penetration between roof joists that are spaced on
72” centers.
Note: Ducts can be installed into the curb from the roof. All
electrical and gas line connections can be made inside the
curb.
FIGURE 12 - CUT AWAY OF ROOF CURB
Johnson Controls Unitary Products35
349687-JTG-A-1007
THERMOSTAT
TERMINALS
W1
1
W2
Y1
2
Y2
G
R
C
4
RC
5
OCC
6
X
TERMINALS ON
A LIMITED
NUMBER OF
THERMOSTATS
CONTROL
TERMINAL
BLOCK
W1
W2
Y1
G
OCC
P
P1
Y2
X
R
SD
C
SD
SD
Smoke
Detector
Jumper
3
24 VAC
Class 2
R
C
1
Second stage heating not required on single stage heating units.
2
Second stage cooling not required on single stage cooling units.
3
Jumper is required if there is no Smoke Detector circuit.
4
Jumper is required for any combination of R, RC, or RH.
5
OCC is an output from the thermostat to indicate the Occupied condition.
6
X is an input to the thermostat to display Error Status conditions.
FIGURE 13 - TYPICAL UNIT WIRING DIAGRAM
36Johnson Controls Unitary Products
349687-JTG-A-1007
GUIDE SPECIFICATIONS
GENERAL
Units shall be manufactured by Johnson Controls in an ISO
9001 certified facility.
Series 20 J**DJ units are convertible single package units. All
models have dual independent refrigerant circuits for efficient
part load operation and maximum comfort control. Although
the units are primarily designed for curb mounting on a roof,
they can also be slab-mounted at ground level or set on steel
beams above a finished roof. Cooling only, cooling with gas
heat and cooling with electric heat models are available with
a wide variety of factory-mounted options and field-i nstalled
accessories to make them suitable for almost every application. All units are self-contained and assembled on full perimeter base rails with holes in the four corners for overhead
rigging. Every unit is completely piped, wired, charged and
tested at the factory to simplify the field installation and to
provide years of dependable operation. All models (including
those with an economizer) are suitable for either bottom or
horizontal duct connections. Models with power exhaust are
suitable for bottom duct connections only. For bottom duct,
remove the sheet metal panels from the supply and return air
openings through the base of the unit. For horizontal duct,
replace the supply and return air panels on the rear of the unit
with a side duct flange accessory. All supply air blowers are
equipped with a belt drive that can be adjusted to meet the
exact requirements of the job. A high static drive option is
available for applications with a higher CFM and/or static
pressure requirement.
Each unit shall have 4 condenser fan motors. All compressors include crankcase heat and internal pressure relief.
Every refrigerant circuit includes an expansion valve, a liquid
line filter-drier, a discharge line high pressure switch and a
suction line with a freezestat and low pressure/loss of charge
switch. The unit control circuit includes a 75 VA transformer,
a 24-volt circuit breaker and a relay board with two compressor lockout circuits, a terminal strip for thermostat wiring, plus
an additional set of pin connectors to simplify the interface of
additional field controls. All units have long lasting powder
paint cabinets with 750 hour salt spray test approval under
ASTM-B117 procedures.All models are CSA approved. All
models include a 1-year limited warranty on the complete
unit. Compressors and electric heater elements carry an
additional 4-year warranty. Aluminized steel tubular heat
exchangers carry an additional 9-year warranty.
DESCRIPTION
Units shall be factory-assembled, single packaged, J**DJN
Electric Cooling/Gas Heat, J**DJC/E Electric Cooling/
Optional Electric Heat, designed for outdoor mounted installation. The 15,17.5, and 20 ton units shall have minimum
EER ratings of 11.1. The 25 ton unit shall have a minimum
EER rating of 10.5.
They shall have built-in field convertible duct connections for
down discharge supply/return or horizontal discharge supply/
return, and be available with factory installed options or field
installed accessories. The units shall be factory wired, piped,
charged with R-22 refrigerant and factory tested prior to shipment. All unit wiring shall be both numbered and color coded.
All units shall be manufactured in a facility certified to ISO
9001 standards and the cooling performance shall be rated in
accordance with DOE and ARI test procedures. Units shall
be CSA listed, classified to ANSIZ21.47 standards, UL 1995/
CAN/CSA No. 236-M90 conditions.
UNIT CABINET
Unit cabinet shall be constructed of a combination of G60 and
G90 galvanized steel, with exterior surfaces coated with a
non-chalking, powdered paint finish, certified at 750 hours
salt spray test per ASTMB117 standards. Indoor blower section shall be insulated with a minimum 1/2" thick insulation,
coated on the airside. Aluminum foil faced insulation shall be
used in the furnace compartment and be fastened with ridged
fasteners to prevent insulation from entering the air stream.
Cabinet panels shall be "large" size, easily removable for servicing and maintenance. Full perimeter base rails shall be provided to assure reliable transit of equipment, overhead rigging
and proper sealing on roof curb applications. Disposable 2" filters shall be furnished and be accessible through a removable
access door, sealed airtight. Units filter track shall be designed
to accommodate either 1" or 2" filters. Fan performance measuring ports shall be provided on the outside of the cabinet to
allow accurate air measurements of evaporator fan performance without removing panels or creating air by-pass of the
coils. Condensate pan shall be internally sloped and conform
to ASHRAE 62-89 self-draining standards. Condensate connection shall be a minimum of 1" I.D. female and be a ridged
mount connection. Unit shall incorporate a fixed outdoor air
damper with an outdoor air intake opening covered with a bird
screen and a rain hood painted to match the exterior of the
unit.
INDOOR (EVAPORATOR) FAN ASSEMBLY
Fan shall be a belt drive assembly and include an adjustablepitch motor pulley. Job site selected (B.H.P.) brake horsepower
shall not exceed the motors nameplate horsepower rating, plus
the service factor. Units shall be designed not to operate above
service factor. Fan wheel shall be double-inlet type with forward-curved blades, dynamically balanced to operate smoothly
throughout the entire range of operation. Airflow design shall be
constant air volume.
A variable air volume (VAV) option using a variable frequency
drive (VFD) is available for applications requiring a constant
supply duct static pressure. Units equipped for VAV shall be
controlled by a duct pressure transducer with a 0 - 5” WC
pressure range. The pressure transducer shall provide a 0 - 5
VDC output signal to a VAV control board which, in tu rn shall
provide a 2 - 10 VDC speed reference signal to the VFD. The
VAV control board shall operate using factory-installed Supply Air, Return Air and Outside Air Temperature Sensors.
Johnson Controls Unitary Products37
349687-JTG-A-1007
Units equipped with VFD’s shall have factory-installed manual bypass as an option.
OUTDOOR (CONDENSER) FAN ASSEMBLY
The outdoor fans shall be of the direct-driven propeller type,
discharge air vertically, have aluminum blades riveted to corrosion resistant steel spider brackets and shall be dynamically balanced for smooth operation. The 4 outdoor fan
motors shall be totally enclosed with permanently lubricated
bearings, internally protected against overload conditions and
staged independently.
REFRIGERANT COMPONENTS
Compressors:
a.Shall be Scroll compressors internally protected with
internal high-pressure relief and over temperature
protection.
b.Shall have internal spring isolation and sound muf-
fling to minimize vibration and noise, and be externally isolated on a dedicated, independent
mounting.
Coils:
a.Evaporator and condenser coils shall have alumi-
num plate fins mechanically bonded to seamless
internally enhanced copper tubes with all joints
brazed. Special Phenolic coating shall be available
as a factory option.
b.Evaporator and Condenser coils shall be of the
direct expansion, draw-thru, design.
Refrigerant Circuit and Refrigerant Safety Components shall
include:
a.Balance-port thermostatic expansion valve with
independent circuit feed system.
b.Filter drier/strainer to eliminate any moisture or for-
eign matter.
UNIT CONTROLS
a.Unit shall be complete with self-contained low-vol t-
age control circuit protected by a resetable circuit
breaker on the 24-volt transformer side.
b.Unit shall incorporate a lockout circuit which pro-
vides reset capability at the space thermostat or
base unit, should any of the following standard
safety devices trip and shut off compressor.
c.Loss-of-charge/Low-pressure switch.
1.High-pressure switch.
2.Freeze-protection thermostat, evaporator coil. If
any of the above safety devices trip, a LED
(light-emitting diode) indicator shall flash a
diagnostic code that indicates which safety
switch has tripped.
d.Unit shall incorporate "AUTO RESET" compressor
over temperature, over current protection.
e.Unit shall operate with conventional thermostat
designs and have a low voltage terminal strip for
easy hook-up.
f.Unit control board shall have on-board diagnostics
and fault code display.
g.Standard controls shall include anti-short cycle and
low voltage protection, and permit cooling operation
down to 0 °F.
h.Control board shall monitor each refrigerant safety
switch independently.
i.Control board shall retain last 5 fault codes in non
volatile memory, which will not be lost in the event of
a power loss.
GAS HEATING SECTION (J**DJN MODELS)
c.Accessible service gage connections on both suc-
tion and discharge lines to charge, evacuate, and
measure refrigerant pressure during any necessary
servicing or troubleshooting, without losing charge.
d.The refrigeration system shall provide at least 15° F
of sub-cooling at design conditions.
e.All models shall have two independent circuits.
f.Hot gas bypass option shall be factory-installed on
compressor #1 discharge line to provide cooling in
low-load applications. HGBP shall be a standard
feature on VAV models and an optional feature on
CV models.
38Johnson Controls Unitary Products
Shall be designed with induced draft combustion with post
purge logic and energy saving direct spark ignition, redundant main gas valve. Ventor wheel shall be constructed of
stainless steel for corrosion resistance. The heat exchanger
shall be of the tubular type, constructed of T1-40 aluminized
steel for corrosion resistance and allowing minimum mixed
air entering temperature of 25° F. Burners shall be of the inshot type, constructed of aluminum coated steel and contain
air mixture adjustments. All gas piping shall enter the unit
cabinet at a single location through either the side or curb,
without any field modifications. An integrated control board
shall provide timed control of evaporator fan functioning and
burner ignition. Heating section shall be provided with the following minimum protection:
349687-JTG-A-1007
a.Primary and auxiliary high-temperature limit switches.
b.Induced draft motor speed sensor.
c.Flame roll out switch (automatic reset).
d.Flame proving controls. Unit shall have two inde-
pendent stages of capacity.
ELECTRIC HEATING (J**DJC/E MODELS)
Nickel chromium electric heating elements shall be provided
as required by the application with 1 or 2 stage control, as
required, from 13.5 KW to 72 KW capacities. The heating
section shall have a primary limit control(s) and automatic
reset to prevent the heating element system from operating
at an excessive temperature. Units with Electric Heating shall
be wired for a single point power supply with branch circuit
fusing (where required).
UNIT OPERATING CHARACTERISTICS
Unit shall be capable of starting and running at 125° F
outdoor temperature, exceeding maximum load criteria of
ARI Standard 340/360. The compressor, with standard
controls, shall be capable of operation down to 25° F outdoor
temperature. Accessory low ambient kit shall be available for
operation to 0° F. Unit shall be provided with fan time delay to
prevent cold air delivery before heat exchanger warms up
(Gas heat only).
ELECTRICAL REQUIREMENTS
All unit power wiring shall enter unit cabinet at a single factory
provided location and be capable of side or bottom entry, to
minimize roof penetrations and avoid unit field modifications.
Separate side and bottom openings shall be provided for the
control wiring.
STANDARD LIMITED WARRANTIES
•Compressor 5 Years
•Heat Exchanger 10 Years
•Electric Heat Element 5 Years
•Other Parts 1 Year
OPTIONAL OUTDOOR AIR (Shall be made available by
either/or):
•ELECTRONIC ENTHALPY AUTOMATIC ECONO-MIZER - Outdoor and return air dampers that are interlocked and positioned by a fully-modulating, springreturn damper actuator. The maximum leakage rate for
the outdoor air intake dampers shall not exceed 2%
when dampers are fully closed and operating against a
pressure differential of 0.5 IWG. A unit-mounted potentiometer shall be provided to adjust the outdoor and return
air damper assembly to take in CFM of outdoor air to
meet the minimum ventilation requirement of the conditioned space during normal operation. During econo-
mizer operation, a mixed-air temperature control shall
modulate the outdoor and return air damper assembly to
prevent the supply air temperature from dropping below
55°F. Changeover from compressor to economizer operation shall be provided by an integral electronic enthalpy
control that feeds input into the basic module. The outdoor intake opening shall be covered with a rain hood
that matches the exterior of the unit. Water eliminator/filters shall be provided. Simultaneous economizer/compressor operation is also possible. Dampers shall fully
close on power loss.
•BAS-READY ECONOMIZER - Outdoor and return air
dampers that are interlocked and positioned by a fullymodulating, spring return damper actuator. The maximum leakage rate for the outdoor air intake dampers
shall not exceed 2% when dampers are fully closed and
operating against a pressure differential of 0.5 IWG.
For units with optional VAV control, free-cooling shall be
available while the outdoor dry bulb temperature (OAT)
remains below a programmable set-point of the controller. Field-installed humidity sensors for either outdoor air
or outdoor & return air streams are available to provide
free-cooling based on single-enthalpy or dual-enthalpy
configurations, respectively. If free-cooling is available, a
call for cooling shall modulate the economizer in order to
maintain a supply air temperature (SAT) programmable
set-point. With the use of a field-installed indoor air quality sensor, the controller shall provide Demand Ventilation by modulating the economizer dampers to allow
more outside airflow upon detection of elevated indoor
CO2 concentrations above a programmable set-point.
With an additional field-installed outdoor air quality sensor, Differential Demand Ventilation shall be provided.
The outdoor intake opening shall be covered with a rain
hood that matches the exterior of the unit. Water eliminator/filters shall be provided.
Simultaneous economizer/compressor operation is also
possible. Dampers shall fully close on power loss.
•MOTORIZED OUTDOOR AIR DAMPERS - Outdoor and
return air dampers that are interlocked and positioned by
a 2-position, spring-return damper actuator. The maximum leakage rate for the outdoor air intake dampers
shall not exceed 2% when dampers are fully closed and
operating against a pressure differential of 0.5 IWG. A
unit-mounted potentiometer shall be provided to adjust
the outdoor and return air damper assembly to take in
the design CFM of outdoor air to meet the ventilation
requirements of the conditioned space during normal
operation. Whenever the indoor fan motor is energized,
the dampers open up to one of two pre-selected positions - regardless of the outdoor air enthalpy. Dampers
return to the fully closed position when the indoor fan
motor is de-energized. Dampers shall fully close on
power loss.
Johnson Controls Unitary Products39
OTHER PRE-ENGINEERED ACCESSORIES AVAILABLE
OTHER FACTORY INSTALLED OPTIONS
•ROOF CURB - 14" high, full perimeter curb with wood
nailer (shipped knocked-down).
•100% BAROMETRIC RELIEF DAMPER - Contains a
rain hood, air inlet screen, exhaust damper and mounting hardware. Used to relieve internal air pressure
through the unit.
•PROPANE CONVERSION KIT - Contains new orifices
and gas valve parts to convert from natural to L.P. gas.
One per unit required.
•HIGH ALTITUDE - NATURAL GAS - Contains orifices
required for applications between 2000 and 6000 feet
altitude.
•HIGH ALTITUDE - PROPANE GAS - Contains orifices
required for applications between 2000 and 6000 feet
altitude. Must be used with propane conversion kit.
•BURGLAR BARS - Designed to work with above roof
curbs, depending on unit model. Fits duct openings of
curb supply and return air openings.
•SIDE DUCT FLANGE - Supply and return air duct
flanges for side duct applications. Do not use on units
with power exhaust.
•HIGH STATIC DRIVE - Includes blower pulley and belt
for higher CFM and/or static pressure requirements.
•WOOD SKID - Allows unit to be handled with 90" forks.
•ECONOMIZER/MOTORIZED DAMPER RAIN HOOD (J25DJN/E/C only) - Contains all hood panels and the
hardware for assembling.
•ANTI-RECYCLE TIMER - Assures 5-minute off time
between compressor cycles.
•LOW AMBIENT KIT - Provides unit cooling operation
down to 0°F.
•COIL GUARD KIT - Guard for cooling coil.
•POWER EXHAUST OPTION - To work in conjunction
with economizers.
•STAINLESS STEEL HEAT EXCHANGER
•STAINLESS STEEL DRAIN PAN
•TECHNICOAT PHENOLIC COATED CONDENSER
AND EVAPORATOR COIL
•ELECTRONIC SINGLE ENTHALPY ECONOMIZER
•DIRTY FILTER SWITCH
•DOUBLE WALL
•PHASE MONITOR
•COIL GUARD
•POWERED GFI CONVENIENCE OUTLET
•NON-POWERED GFI CONVENIENCE OUTLET
•BAS READY ECONOMIZER (2-10 V.D.C. ACTUATOR
WITHOUT A CONTROLLER)
•HINGED FILTER DOOR ACCESS AND TOOL FREE
ACCESS PANELS
•JOHNSON LIGHT COMMERCIAL SYSTEM (LCCS) Provides rooftop system integration for LCCS single
zone, change-over bypass and VAV systems.
•JOHNSON UNT 1126 ROOFTOP CONTROLLER - N2
protocol with air proving and dirty fi lt er sensors. Hardware contains generic application logic; field engineering
and/or modification may be required.