Johnson Controls A419 User Manual

Features and Benefits

Product/Technical Bull eti n A419

Issue Date August 13, 2014

A419 Series Electronic Temperature Controls with Display

and NEMA 1 or NEMA 4X Watertight Enclosures

The A419 series controls are single-stage, electr o nic
temperature controls with a Single-Pole, Double-Throw
(SPDT) output relay. They feature a lockable
front-panel touchpad for setup and adjustment, and an
LCD for viewing the temperature and status of other
functions. An LED indicates the controls’ output relay
On/Off status. The A419 controls are available in 24
VAC or 120/240 VAC powered models.

The A419 controls have heating and cooling modes,
adjustable setpoint and diff erenti al, an adjus ta ble
anti-short cycle delay, and a temperature offset
function. The setpoint range is -30 to 212°F
(-34 to 100°C). The controls feature remote sensing
capability and interchangeable sensors. The
A419 controls are available in either NEMA 1,
high-impact plastic enclosure suitable for surface or
DIN rail mounting or NEMA 4X watertight,
corrosion-resistant surface-mount enclosures.

Figure 1: A419 Temperature Control with NEMA 1

Enclosure and A99 Temperature Sensor

 Easy-to-Read Front-Panel

Liquid Crystal Display

 Wide Temperature Differential Adjustment

Range (1 to 30F° or C°)

 Adjustable Anti-Short Cycle Delay

(0 to 12 Minutes in 1-Minute Increments)

 Switch-Activated Temperature Offset

Function

 High-Impact, Thermoplastic NEMA 1 or

NEMA 4X Watertight, Corrosion-Resistant
Enclosures

Displays the sensed temperature and control-function
status clearly; custom icons on the display indicate the
control and system status at a glance

Allows the user to set a precise (1F° or C°) temperature
differential from 1 to 30F° or C°; providing a much
tighter differential than electromechanical controls

Ensures that the output relay remains off for a user-set
time delay, which helps avoid hard starts, nuisance
overload outages, and unnecessary equipment wear

Allows the user to shift the cut-in and cutout setpoints
by an adjustable offset based on the status of a
user-installed, external switch, such as a time clock

Increase application options, allowing surface and
snap-fit DIN rail mount, or Watertight surface mount

 Lockable Front Panel Touchpad Allows easy set up and adjustment of the A419 control

setpoint, differential, and other functions; a concealed
jumper locks the touchpad, and deters unauthorized
adjustment of the control settings

 Low- and Line-Voltage Models Provide options for most refrigeration and HVAC

control-voltage applications

© 2014 Johnson Controls, Inc. 1
Code No. LIT-125188 www.johnsoncontrols.com

1/2

(13)

2-15/16

(75)

1-9/16
(40)

7/16

(11)

DIN

Rail

2-3/8

2-3/8

(61)

(61)

2-3/8

(61)

7/8

7/8

Sensor

2

(50)

5

(127)

4

(102)

1/4

(6)

9/64

Conduit Hole

MENU

(3.7)

(1/2 in. Trade Size)

(22)

(22)

A419

MENU

2-1/4

(56)

2-13/16

(71)

6-1/8
(155)

1-3/4

(44)

1-1/16

(27)

(71)

2-13/16

Position the A99 sensor
in the b racket at the bottom of
the A419 NEMA 4X encl os u re.

6-5/8
(168)

Application

IMPORTANT: The A419 Series Temperature

Controls are intended to control equipment under
normal operating conditions. Where failure or
malfunction of an A419 Series Control could lead to
an abnormal operating condition that could cause
personal injury or damage to the equipment or other
property, other devices (limit or safety controls) or
systems (alarm or supervisory) intended to warn of
or protect against failure or malfunction of the A419
Series Control must be incorporated into and
maintained as part of the control system.

The A419 Electronic Temperature Control can be used
to control a wide variety of single-stage refrigeration or
HVAC equipment. T ypical applicat ions incl ude :

• retail store display freezers and reach-in coolers

• supermarket display cases for produce/meats

• retail store walk-in coolers and freezers

• boiler operating control (used as a thermostat)

• condenser fan cycling or staging

• cooling tower pump and fan control

Dimensions

Figure 2: A419 Temperature Control with

NEMA 1 Enclosure, Dimensions, in./(mm)

• space and return air temperature control

FCC Compliance

This device complies with Part 15 of the FCC Rules.
Operation is subject to the following two conditions:
(1) this device may not cause harmful interference,
and (2) this device must accept any interference that
may cause undesired operation.

This equipment has been tested and found to comply
with the limits for a Class A digital device pursuant to
Part 15 of FCC rules. These limits are designed to
provide reasonable protection against harmful
interference when this equipment is operated in a
commercial environment. This equipment generates,
uses, and can radiate radio frequency energy and, if
not installed and used in accordance with the
instruction manual, may cause harmful interference to
radio communications. Operation of this equipment in
a residential area may cause harmful interference, in
which case the users will be required to correct the
interference at their own expense.

Canadian Compliance Statement

This digital apparatus does not exceed the Class A
limits for radio noise emissions from digital apparatus

Figure 3: A419 Temperature Control with

NEMA 4X Watertight, Corrosion-resistant,

Enclosure, Dimensions, in./(mm)

set out in the Radio Interference Regulations of the
Canadian Department of Communications.

2 A419 Series Electronic Temperature Controls with Display and NEMA 1 or NEMA 4X Watertight Enclos ur es
Product/Technical Bull eti n

MENU

F

BIN

MENU Button
DOWN Arrow

Button

UP Arrow

Button

Output Relay

Status Indicator

LED

Operating Mode

Indicator

Temperature

Units Indicator

Temperature

Offset Indica tor

Liquid Crystal

Display

Liquid Crystal Display

During normal operation, the LCD displays the
temperature at the sensor, the units of temperature
(°F or °C), and an icon indicating if the control is set for
Heating (

) or Cooling ( ) mode. The LCD also
displays BIN if the Temperature Offset function is
activated. See Figure 5.

During control set up or adjustment, the LCD displays
the control functions and their values (settings). After
30 seconds of inactivity, the display returns to the
sensed-temperature displ a y. See the Adjustments
section to adjust the control setting.

Output Relay Status Indicator LE D

A green LED on the control’s front panel illuminates
when the SPDT output relay is energized and the
Normally Open (N.O.) contacts are closed.
See Figure 5.

Figure 4: A419 Temperature Control with NEMA 4X

Enclosure and A99 Temperature Sensor

Operation Overview

A419 Control Definitions
Cut-in is the temperature at which the N.O. contacts

on the SPDT output relay close.
Cutout is the temperature at which the N.O contacts

on the SPDT output relay open.

The A419 control’s front-panel, LCD, LED, and the
A419 control functions are described below. See the
Adjustments section for instructions on setting up and
adjusting the A419 control.

A419 Control Front-Panel

The front panel of the A419 control has a three-button
touchpad and LCD for adjusting control function
values, and an LED indicator that displays the On/Off
status of the SPDT output relay. See Figure 5.

A419 Functions Set at the Front-Panel
Setpoint (SP) establishes the temperature value that

energizes or de-energizes the output relay, depending on
the user selected mode of operation. The control may be
set either to cut in or to cut out at Setpoint. See the
Cooling/Heating and Setpoint Modes. The Setpoint range
is -30 to 212°F (-34 to 100°C).

If Setpoint mode is Cut-in, Setpoint is the temperature
value that closes the N.O. contacts. If Setpoint mode is
Cutout, Setpoint is the temperature value that opens
the N.O. contacts. See Figure 7 and Figure 8.

Differential (dIF) establishes the difference in
temperature (in F° or C°) between the cut-in and
cutout values. The differential is set relative to Setpoint
and may be set from 1 to 30F° or C°. See Figure 7 and
Figure 8.

Anti-Short Cycle Delay (ASd) establishes the
minimum time that the N.O. contacts remains open (after

reaching cutout) before closing again. The delay overrides
any Load Demand and does not allow the N.O. contacts
to close until the set time-delay value has elapsed. See
Figure 6. When the delay is activated, the LCD
alternately flashes the sensor temperature and ASd. The
delay may be set for 0 to 12 minutes in 1-minute
increments.

Figure 5: A419 Control Front-Panel with Display

A419 Series Electronic Temperature Controls with Display and NEMA 1 or NEMA 4X Watertight Enclosures

Product/Technical Bulletin 3

Anti-short

Cycle D el ay

Load Demand
Output Status

Time

Off

Off

On

On

Load Demand

Overridden

Mode of

Operation

Temperature

Offset Value

Secondary

Setpoint*

Heating

70°

8°

62°

(BIN and COM) is closed

For example, if the anti-short cycle delay is set for
7 minutes, the A419 control will not restart the
equipment for 7 minutes after the equipment has cut
out, even if the cut-in temperature value is reached
during the delay. If the temperature reaches the cut-in
value during the delay period, the display flashes
between the sensed temperature and ASd, indic ati ng
that the next On-cycle is being delayed. After the set
delay time has elapsed, the A419 control returns to
normal operation, restarts the equipment (if cut-in has
been reached), ASd stops flashing, and the LCD
reverts to the normal operating display.

Note: Any interruption in supply power to the
A419 control activates the anti-short cycle delay.

Figure 6: Anti-short Cycle Delay

Sensor Failure Operation (SF) establishes how the

A419 control operates the equipment in the event of a
sensor or sensor-wiring failure. The A419 control may
be set to run the equipment continuously or to shut it
down if the sensor or sensor wire fails. When a failure
is detected the LCD flashes SF alternatel y with OP if
the sensor circuit is open, or SF and SH if the sensor
circuit is shorted. The control implements a 1-minute
delay before initiating a failure response to allow for
verification of the failure condition and to avoid
nuisance failure indications.

Temperature Units establishes the units of
temperature (F° or C°) displayed on the LCD.

Temperature Offset (OFS) establishes the value of
setpoint-shift (in F° or C°) applied to Setpoint (and
Differential) when a (user-installed) circuit is closed
between the binary input (BIN) and common (COM)
terminals. The offset value may be set from 0 to 50F°
or C°.

The Temperature Offset function is used to reset the
Heating Setpoint to a lower temperature (secondary)
setpoint or reset the Cooling Setpoint to a higher
temperature (secondary) setpoint by the temperature
value set in Temperature Offset.

The BIN and COM terminals may be connected to a
(user-supplied) external switching device, such as a
time clock, that has a set of Single-Pole, Single-Throw
(SPST) contacts. Closing a circuit between the BIN
and COM terminals activates the Temperature Offset.
See Wiring.

This function enables the control to alternate between
two temperature setpoints based on the position of the
binary input switch. The difference between the
primary and secondary setpoints (in F° or C°) is set in
the Temperature Offset function (OFS) using the
touchpad. See Setting Other Functions.

Table 1 shows an example of Temperature Offset.

Table 1: Temperature Offset Example

Setpoint

Cooling

* Setpoint when circuit between binary input terminals

70° 8° 78°

When the circuit is closed between the binary input
(BIN) common (COM) terminals, the offset function is
enabled and the A419 control cycles on the secondary
setpoints. BIN is displayed on the LCD above the °F or
°C symbol when the offset is enabled. See Figure 5.

A419 Control Functions Set by Jumper Position

For instructions on positioning jumpers, see
Positioning the Jumpers in the Adjustments section.
See Figure 12 and Figure 13.

Touchpad Lock: The jumper at P5 establishes
whether the touchpad is locked or unlocked. Locking
the touchpad deters accidental or unauthorized
changes to all of the function parameters.

Heating/Cooling Mode is established by positioning
the jumper on the top two pins of the P4 jumper. See
Figure 13.

Setpoint Mode: Removing or installing the lower
jumper at P4 establishes whether Setpoint is the cut-in
temperature or cutout temperature. See Figure 13.

Cooling/Heating and Setpoint Modes

The A419 control may be in four operating modes:

Cooling/Cut-in, Cooling/Cutout, Heating/Cut-in, and
Heating/Cutout. Position the jumpers located on the

circuit board under the A419 control cover to set the
desired mode of operation. See Positioning the
Jumpers.

In Cooling/Cut-in mode the differential is below
Setpoint. The output relay energizes and the LED
illuminates when the temperature rises to Setpoint.
When the temperature drops to Setpoint minus the
differential value, the relay and LED de-energize.

4 A419 Series Electronic Temperature Controls with Display and NEMA 1 or NEMA 4X Watertight Enclos ur es
Product/Technical Bull eti n