Johnson Controls A419 Series - Manual (Page 5)

A419 Series Electronic Temperature Controls with Display and NEMA 1 or NEMA 4X Watertight Enclosures
Product/Technical Bulletin 5
In Cooling/Cutout mode the differential is above
Setpoint. The output relay energizes and LED
illuminates when the temperature rises to Setpoint plus
the differential value. When the temperature drops to
Setpoint, the relay and LED de-energize.
Setpoint
(+) Cooling/Cut-out
Cooling/Cut-in
Cut-out
(-)
Differential
Differential
Temperature
(Off)
Cut-in
(On)
Cut-in
(On)
Cut-out
(Off)
Figure 7: Cooling Modes
When the Heating/Cut-in mode is selected, the
differential is above Setpoint. The output relay
energizes and LED indicator illuminates when the
temperature drops to Setpoint. When the temperature
rises to Setpoint plus the differential value, the output
relay and LED de-energize.
When Heating/Cutout mode is selected, the
differential is below Setpoint. The output relay
energizes and LED indicator illuminates when the
temperature drops to Setpoint minus the differential
value. When the temperature rises to Setpoint, the
output relay and LED indicator de-energize.
Setpoint
(+)
Heating/Cut-out
Heating/Cut-in
(-)
Temperature
Differential
Cut-out
(Off)
Cut-in
(On)
Differential
Cut-in
(On)
Cut-out
(Off)
Figure 8: Heating Modes
Mounting
An A419 control has either a standard high-impact
plastic NEMA 1 or a NEMA 4X corrosion-resistant,
watertight enclosure.
The A419 control is not position sensitive but should
be mounted for convenient wiring and adjustment.
Note: When mounting the control to rigid conduit,
attach the hub to the conduit before securing the hub
to the control enclosure.
The mounting hole pattern of the NEMA 1 enclosure is
identical to that of the System 350
 controls, and most
models of the A19 control. The NEMA 1 enclosure
may also be mounted on 35 mm DIN rail. See Figure 1
and Figure 2.
The NEMA 4X models may be mounted to flat vertical
surfaces using the four screw holes at the enclosure
corners. See Figure 3 and Figure 4. To maintain the
watertight and corrosion resistant integrity of the
NEMA 4X enclosure, use a conduit fitting rated for the
environment in which the control is installed.
An additional (low-voltage) two-wire cable is required
to operate the temperature offset function. On
NEMA 4X enclosures you must install a suitable
liquid-tight fitting in an available knockout to pass the
two-wire cable through the enclosure wall.
IMPORTANT: The short-lead A99 sensor,
included with A419 NEMA 4X model controls, must
be mounted on the bottom of the control in the
bracket molded on the NEMA 4X housing. Mounting
the sensor on top of the control may reduce the
accuracy of the displayed temperature. See Figure 3
and Figure 4 for proper sensor position.