Selecting The Control Operation (Forward/Reverse); Forward (Cooling)/Reverse (Heating); Setting The Control Operation (Pins 4 And 5) - Omron CJ Series Operation Manual

Selecting the Control Operation (Forward/Reverse)

3-4

Selecting the Control Operation (Forward/Reverse)

3-4-1

Forward (Cooling)/Reverse (Heating)

3-4-2

Setting the Control Operation (Pins 4 and 5)

Example Setting
54
With forward operation (cooling), the manipulated variable is increased as the
PV increases. With reverse operation (heating), the manipulated variable is
increased as the PV decreases.
Manipulated variable
100%
0%
Low SV
temperature
Forward operation
For example, when heating control is being performed and the present tem-
perature (PV) is lower than the set point (SP), the manipulated variable is
increased proportionally as the difference between the PV and SP increases.
Consequently, heating control uses "reverse operation" and cooling control
uses "forward operation."
Set reverse operation or forward operation with pins 4 and 5 of the Unit's DIP
switch. Pin 4 controls the operation of loops 1 and 3; pin 5 controls the opera-
tion of loops 2 and 4.
If pin 4 is turned OFF and pin 5 is turned ON, loops 1 and 3 will be set for
reverse operation (heating) and loops 2 and 4 will be set for forward operation
(cooling).
The following diagram shows pins 4 and 5 set to their factory settings (OFF),
which sets reverse operation (heating) for all loops.
If this setting is changed during operation, the new setting will not become
effective until the power is turned ON or the Unit is restarted.
Manipulated variable
100%
0%
Low
High
temperature
temperature
Pins 4 and 5
Control Operation
Setting
Reverse OFF
Forward ON
Section 3-4
SV High
temperature
Reverse operation