System 350 A350E Electronic Cooling Control Product/Technical Bulletin
3
Differential Adjustment
Differential is defined as the change in sensor
temperature between the energization and
de-energization of the relay. (See Figure 3.) The
differential can be adjusted between 1 and 30F°
(0.6 and 16.7C°). Adjustment is made using the differential
potentiometer, marked DIFF. (See Figure 2 for location.)
ON
OFF
(+)
(-)
Di
ffer
e
nt
ia
l
ON = Energized
OFF = De-energized
Setpoint
Temperature
OFF
D
iff
er
en
tia
l
ON
OFFSET
Figure 3: Relationship Between Differential
Setpoint and Offset
A
dd-On Modules
The S350 Stage Modules, D350 Digital Temperature
Display Module, and Y350R Power Module connect
together and plug into a connector on the right side of
the A350E. The maximum number of add-on modules
is listed in Table 1.
Table 1: Maximum Number of S350 Stage
Modules per A350E
Power
Source
Number
of S350A
or S350C
Modules
Allowed
Number of
S350A or
S350C
Modules
(with
1 S350P)
Allowed
Number
of S350A
or S350C
Modules
(with
2 S350Ps)
Allowed
Y350R
9
6
4
External
Class 2
Transformer
9
8
7
S350A On/Off Stage Modules
S350A On/Off Stage Modules receive power, setpoint,
and sensor input from the A350E control. S350A Stage
Modules perform switching functions based upon the
A350E’s setpoint, sensor information, with the offset and
differential selected at the S350A. For more information
on these modules, refer to the
System 350
TM
S350
Temperature, S351 Humidity, and S352 Pressure On/Off
Stage Modules Product/Technical Bulletin (LIT-930080).
S350C Slave Stage Modules
S350C Slave Stage Modules receive power and
sensor input from the A350E control. S350C Slave
Stage Modules perform switching functions based
upon the A350E’s sensor information, with the setpoint
and differential selected at the S350C. For more
information on these modules, refer to the
System 350
TM
S350C Temperature Slave Stage
Module Product/Technical Bulletin (LIT-930084).
S350P Proportional Stage Modules
S350P Proportional Stage Modules receive power,
setpoint, and sensor input from the A350E control. The
S350P responds with an analog 0 to 10 VDC and
0 to 20 mA output signal. This is based upon the
A350E’s setpoint and sensor information, with the offset,
throttling range, and minimum output selected at the
S350P.
For more information on these modules, refer to the
System 350
TM
S350P Proportional Plus Integral
Temperature Stage Module Product/Technical Bulletin
(LIT-930086).
D350 Temperature Sensor/Setpoint
Display Module
The D350 receives its power, sensor, and setpoint
information from the A350E. A 3-digit Liquid Crystal
Display (LCD) gives a continuous read-out of the
sensed temperature. The setpoint of the adjoining
A350E is displayed when the PRESS FOR SETPOINT
button on the front of the D350 is pushed.
Y350R Power Module
The Y350R provides a convenient method of powering
System 350 Modules from a 120 or 240 VAC power
source. See Figure 5 for a typical wiring diagram where
a Y350R is used to power the A350E. Up to nine
S350A/C stage modules and one D350 can be
operated from a Y350R.
For more information on this module, refer to
System 350
TM
Y350R Power Module
Product/Technical Bulletin (LIT-930090).