Johnson Controls Penn A421 Series User manual

LIT-1900935
2020-04-14
A421 Series Electronic
Temperature Controls with Off-
Cycle Defrost Catalog Page
A421ABD, A421AED, A421AED
Description
The A421 Series Standard Electronic Temperature
Controls are single stage, electronic temperature
controls with a single-pole, double-throw (SPDT) output
relay. The controls feature an adjustable backlit LCD for
viewing the temperature and status of other functions,
and a three-button touchpad for setup and adjustment.
An LED indicates the On/Off status of the output relay.
The A421 Controls are available in 120 VAC and 240 VAC
models.
The A421 Control with Defrost allows you to set up
regular, passive defrost periods of 1 minute to 99
minutes. The defrost interval can range from 2 hours to
24 hours, or be set to 0 for no defrost interval. You can
also start or stop a defrost off-cycle in two ways: press
the three-button touchpad on the Advanced Menu or
connect a momentary switch to the Binary Input (BIN).
The A421 also provides sensor offset, temperature
setback, adjustable anti-short cycle delay, and a
restricted user adjustment mode. The temperature
units can be displayed in °F or °C. The temperature
adjustment range is -40°F to 212°F or -40°C to 100°C.
The A421 Controls are available in Type 1, IP20 high-
impact plastic enclosures suitable for surface or DIN
rail mounting and Type 4X, IP66 watertight, corrosion-
resistant surface mount enclosures.
Refer to the A421 Series Electronic Temperature Controls
Product Bulletin (LIT-12012219) for important product
application information.

Applications
You can use the A421 Control to manage a
wide range of single-stage refrigeration or
HVAC equipment. Sample temperature control
applications include:
• On/off control chillers
• Chiller pump control
• Cooling control
Features and benefits
Control front panel LCD
Displays the temperature, parameters, and status.
You can adjust the backlight intensity for ambient
light conditions. Custom icons display the system
and control status.
Basic and Advanced programming menu
Provides two levels of parameter adjustment and
control. You can set up advanced features in one
menu and adjust basic parameters in the other
menu.
Off-Cycle defrost
Shut off the refrigeration system for defined defrost
time interval and frequency. You can also start or
stop a manual only defrost off-cycle.
On/Off temperature adjustment
Select the temperature values at which the relay
turns on and off and automatically define the mode
of operation.
Switch-activated temperature setback
Shift the On/Off temperature by an adjustable
setback. When a user-supplied switch closes the
binary input control circuit, temperature setback is
enabled.
Adjustable anti-short cycle delay (ASd)
Select the minimum time the output relay
remains off before the next on-cycle. By selecting
this minimal time, you can avoid short cycling,
hard starts, and nuisance overload outages on
compressors and other inductive applications.
Adjustable sensor offset
Adjust the displayed temperature to the actual
sensed temperature.
Optional restricted adjustment mode
Restrict the On/Off adjustment to your defined
temperature range.
Sensor failure mode
Run the control continuously in the event of a
sensor or sensor wire failure or to shut it down.
Backlight brightness level
Adjust the brightness of the backlighting of the LCD
screen. The backlight brightness level is applied
during normal operation. When you set up or adjust
the parameters, the LCD automatically goes to the
brightest level.
Repair information
Do not attempt to repair or recalibrate the A421
Series Electronic Temperature Control. In case
of a defective or improperly functioning control,
contact your nearest authorized Johnson Controls®
or PENN® distributor or sales representative.
When contacting your Johnson Controls or PENN
distributor, have the model number of the control
available. This number can be found on the label
inside the cover of the control.
Ordering information
Contact your nearest Johnson Controls or PENN
distributor or sales representative to order sensors,
mounting hardware, and other accessories to
install the A421 Controls. Contact your local
Johnson Controls or PENN representative for
more information on options available for high-
volume purchase models with specific application
requirements.
2 A421 Series Electronic Temperature Controls with Off-Cycle Defrost Catalog Page

Selection charts
Table 1: A421 Series Standard Electronic
Temperature Control
Product code Description
A421ABD-02C Line -Voltage Type 1 Electronic Temperature
Control with Off-Cycle Defrost Timer: Type 1
(NEMA), IP20 standard enclosure for DIN rail
and surface-mount applications. Rated for
120/240 VAC. Includes timer for On/Off defrost
cycle control. Includes A99BB-200C temperature
sensor with 6.6 ft (2.0 m) cable.
A421AED-01C Line -Voltage Type 4X Electronic Temperature
Control with Off-Cycle Defrost Timer: Type 4X
(NEMA), IP66 standard enclosure for surface-
mount applications. Rated for 120/240 VAC.
Includes timer for On/Off defrost cycle control.
Includes A99BB-25C temperature sensor with 9
7/8 in. (0.25 m) cable.
A421AED-02C Line -Voltage Type 4X Electronic Temperature
Control with Off-Cycle Defrost Timer: Type 4X
(NEMA), IP66 standard enclosure for surface-
mount applications. Rated for 120/240 VAC.
Includes timer for On/Off defrost cycle control.
Includes A99BB-200C temperature sensor with
6.6 ft (2.0 m) cable.
Table 2: A99 Temperature Sensors
Product code1
Description
A99BA-200C Positive temperature coefficient (PTC)
Temperature Sensor: Standard probe 2 in. (5.1
cm) with 6.6 ft (2.0 m) shielded polyvinyl chloride
(PVC) cable; ambient operating temperature
range: -40ºF to 212ºF (-40ºC to 100ºC)
A99BB-25C PTC Temperature Sensor: Standard probe 2
in. (5.1 cm) with 9 7/8 in. (0.25 m) PVC cable;
ambient operating temperature range: -40ºF to
212ºF (-40ºC to 100ºC)
A99BB-200C PTC Temperature Sensor: Standard probe 2 in.
(5.1 cm) with 6.6 ft (2.0 m) PVC cable; ambient
operating temperature range: -40ºF to 212ºF
(-40ºC to 100ºC)
A99BB-300C PTC Temperature Sensor: Standard probe 2 in.
(5.1 cm) with 9.8 ft (3.0 m) PVC cable; ambient
operating temperature range: -40ºF to 212ºF
(-40ºC to 100ºC)
A99BB-400C PTC Temperature Sensor: Standard probe 2 in.
(5.1 cm) with 13.1 ft (4.0 m) PVC cable; ambient
operating temperature range: -40ºF to 212ºF
(-40ºC to 100ºC)
A99BB-600C PTC Temperature Sensor: Standard probe 2 in.
(5.1 cm) with 19.7 ft (6.0 m) PVC cable; ambient
operating temperature range: -40ºF to 212ºF
(-40ºC to 100ºC)
Table 2: A99 Temperature Sensors
Product code1
Description
A99BC-25C11PTC Temperature Sensor: Standard probe 2 in.
(5.1 cm) with 9 7/8 in. (0.25 m) high-temperature
silicon cable; ambient operating temperature
range: -40ºF to 248ºF (-40ºC to 120ºC)
A99BC-100C1PTC Temperature Sensor: Standard probe 2 in.
(5.1 cm) with 3.3 ft (1.0 m) high-temperature
silicon cable; ambient operating temperature
range: -40ºF to 248ºF (-40ºC to 120ºC)
A99BC-300C1PTC Temperature Sensor: Standard probe 2 in.
(5.1 cm) with 9.8 ft (3.0 m) high-temperature
silicon cable; ambient operating temperature
range: -40ºF to 248ºF (-40ºC to 120ºC)
A99BC-500C1PTC Temperature Sensor: Standard probe 2 in.
(5.1 cm) with 16.4 ft (5.0 m) high-temperature
silicon cable; ambient operating temperature
range: -40ºF to 248ºF (-40ºC to 120ºC)
A99BC-1500C1PTC Temperature Sensor: Standard probe 2 in.
(5.1 cm) with 49.2 ft (15.0 m) high-temperature
silicon cable; ambient operating temperature
range: -40ºF to 248ºF (-40ºC to 120ºC)
A99CB-200C PTC Temperature Sensor: Extended probe 6 in.
(15.2 cm) with 6.6 ft (2.0 m) PVC cable; ambient
operating temperature range: -40ºF to 212ºF
(-40ºC to 100ºC)
A99CB-600C PTC Temperature Sensor: Extended probe 6 in.
(15.2 cm) with 19.7 ft (6.0 m) PVC cable; ambient
operating temperature range: -40ºF to 212ºF
(-40ºC to 100ºC)
1 When any A99 Series Temperature Sensor is connected
to a standard A421 Control model, the range of displayed
temperature values is -40°F to 212°F or -40°C to 100°C.
Table 3: Accessories for the A421 Controls
Product code Description
BKT287-1R 12 in. (305 mm) long DIN rail section
BKT287-2R 36 in. (914 mm) long DIN rail section
PLT344-1R Two end clamps for DIN rail sections
A99-CLP-1 Surface mounting clip for A99B and A99C Series
Temperature Sensors
SHL10-603R Sun shield for A99B and A99C Series
Temperature Sensors
BOX10A-603R PVC enclosure for A99B and A99C Series
Temperature Sensors
WEL11A-601R Immersion well for applying sensor in fluid
applications
3 A421 Series Electronic Temperature Controls with Off-Cycle Defrost Catalog Page

Technical specifications
Table 4: A421 Series Electronic Temperature
Control Technical Specifications
Specification Description
Power
consumption
1.8 VA maximum
Supply power Class 2: 108/110/115/120 or 208/230/240
VAC, 50/60 Hz
Type 1/IP20:
Operating: -40°F to 150°F (-40°C to 66°C), 0%
to 95% RH noncondensing
Shipping and storage: -40°F to 185°F (-40°C
to 85°C), 0% to 95% RH noncondensing
Ambient
conditions
Type 4X/IP66:
Operating: -40°F to 140°F (-40°C to 60°C)
Shipping and storage: -40°F to 140°F (-40°C
to 60°C)
Temperature
control range
-40°F to 212°F or (-40°C to 100°C)
Sensor type A99 PTC temperature sensor, 1,035 ohm at
77°F (25°C)
Sensor offset
range
±5ºF or ±3ºC
Enclosure material Type 1: IP20 high-impact thermoplastic or
Type 4X: IP66 watertight, corrosion-resistant,
high-impact thermoplastic
Compliance North America: cULus Listed; UL 60730, File
E27734, Vol. 1; FCC Compliant to CFR47, Part
15, Subpart B, Class B Industry Canada (IC)
Compliant to Canadian ICES-003, Class B
limits
Europe: CE Mark – Johnson Controls declares
that this product is in compliance with the
essential requirements and other relevant
provisions of the EMC Directive; Low Voltage
Directive.
Australia: Regulatory Compliant Mark (RCM)
The performance specifications are nominal
and conform to acceptable industry standards.
For application at conditions beyond these
specifications Johnson Controls shall not be liable
for damages resulting from misapplication or
misuse of its products.
Product warranty
This product is covered by a limited
warranty, details of which can be found at
www.johnsoncontrols.com/buildingswarranty.
Software terms
Use of the software that is in (or constitutes)
this product, or access to the cloud, or hosted
services applicable to this product, if any,
is subject to applicable terms set forth at
www.johnsoncontrols.com/techterms. Your use
of this product constitutes an agreement to such
terms.
Single point of contact
APAC Europe NA/SA
JOHNSON CONTROLS
C/O CONTROLS PRODUCT
MANAGEMENT
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DISTRICT
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CHINA
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45143 ESSEN
GERMANY
JOHNSON CONTROLS
507 E MICHIGAN ST
MILWAUKEE WI 53202
USA
Contact information
Contact your local branch office:
www.johnsoncontrols.com/locations
Contact Johnson Controls:
www.johnsoncontrols.com/contact-us
© 2020 Johnson Controls. All rights reserved. All specifications and other information shown were
current as of document revision and are subject to change without notice.
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