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.