5-33
• Automatic changeover A
Set 1 in setup data setting
C26
to allow automatic changeover to set the
temperature (switch point) where channels are switched and the dead band
setting that prevents switch chattering. Examples 1 to 4 below describes switch
operations.
Example 1:
(1) When the high-temperature sensor senses that the temperature has risen to
changeover point A, the channel switches from the low-temperature to the
high-temperature sensor.
(2) No switching is performed at changeover point C when the high-
temperature sensor senses that the temperature has only reached point B
and does not exceed the upper limit of the dead band.
(3) When the high-temperature sensor senses that the temperature has dropped
to point D the lower limit of the dead band, the channel switches from the
high-temperature to the low-temperature sensor.
Example 2:
(1) When the temperature rises and the high-temperature sensor senses that the
temperature has risen to changeover point A, the channel switches from the
low-temperature sensor to the high-temperature sensor.
(2) When the high-temperature sensor senses that the temperature has risen
above the upper limit of the dead band and reached point B, the channel
switches from the high-temperature to the low-temperature sensor at
changeover point C.
A
B
C
D
+
–
1/2 dead band
1/2 dead band
Changeover
setting
Low temper-
ature sensor
High temper-
ature sensor
Low temper-
ature sensor
High temper-
ature sensor
Low temperature
sensor
Chapter 5. FUNCTIONS
A
B
C
+
–
1/2 dead band
1/2 dead band
Changeover
setting
Low temper-
ature sensor
High temper-
ature sensor
Low temper-
ature sensor
High temper-
ature sensor
Low temperature
sensor
