Johnson Controls A350E User Manual

2
System 350 A350E Electronic Cooling Control Product/Technical Bulletin
A
pplication
The A350E Cooling Control can be used as a
standalone device or in conjunction with other
System 350 plug-together accessory modules to
control a wide variety of single or multiple-stage
equipment. Typical applications include:
•
frozen/refrigerated food cases
•
cooling tower control
•
beverage/milk coolers
•
chiller staging
•
space temperature control (cooling only)
A typical cooling control scheme includes the following:
•
A350E Cooling Control
•
One or more S350 Stage Modules
•
D350 Digital Temperature Sensor/Setpoint Display
Module
•
Y350R Power Module (or 24 VAC Class 2
transformer)
•
A99B Temperature Sensor
O
peration
The A350E Cooling Control operates on 24 VAC and
provides an SPDT relay output. A front-panel LED
lights to indicate when the relay is energized.
Adjustable features include:
•
setpoint
•
differential
•
minimum setpoint
IMPORTANT: All System 350 controls are
designed for use
only
as
operating controls. Where an
operating control failure would
result in personal injury and/or
loss of property, it is the
responsibility of the installer to add
devices (safety, limit controls) that
protect against, or systems
(alarm, supervisory systems) that
warn of, control failure.
Setpoint Adjustment
Setpoint is defined as the temperature at which the
A350E’s relay will de-energize. Refer to Figure 3
.
Use
the Setpoint Dial on the front of the A350E to adjust
setpoint. See Figure 2.
Minimum Setpoint Jumper
Four possible settings are available: 20°F (-7°C),
30°F (-1°C), 40°F (4°C), and Off. Refer to Figure 2 and
use the jumper to select the desired minimum setpoint.
The minimum setpoint function overrides any knob-
selected setpoint that is lower than the minimum
setpoint. For example, if a minimum setpoint of 40°F is
selected and the dial is set at 32°F (0°C), then the
control setpoint will be 40°F (4°C). The external knob
will change the control setpoint only when it is adjusted
between 40 and 65°F (4 to 18°C).
When the minimum setpoint jumper is removed or the
Off position is selected, the setpoint can be adjusted
over the full range of 10 to 65°F (-12 to 18°C).
Setpoint
Dial
Module
Connector
Relay
LED Indicator
Minimum
Setpoint Jumper
OFF
N.C.
Relay
COM
Output
N.O.
Terminals
Relay
DIFF
(Differential
Potentiometer)
RelayRelay
24V
COM
COM
SEN
20 F (-7 C)°°
30 F (-1 C)°°
40 F (4 C)°°
Figure 2: A350E Electronic Cooling Control
Board Layout and Terminal Locations

Johnson Controls A350E Specifications

General

Brand	Johnson Controls
Model	A350E
Category	Controller
Language	English