Chapter 5. FUNCTIONS
• Automatic changeover B
To combine external switch input conditions with automatic changeover A, enter 2
in setup data setting
C26
and 9 or 10 in one of settings
C71
to
C74
.
When 9 is entered in
C71
to
C74
and the external switch is on, it is tied to channel 1.
When it is off, it is possible to switch channels from channel 1 to 2.
When 10 is entered in
C71
to
C74
and the external switch is on, it is tied to channel 2.
When it is off, it is possible to switch channels from channel 2 to 1.
• Automatic changeover C
Enter 2 in setup data
C26
when the PV to be calculated is the value between the low-
temperature sensor and high-temperature sensor in the dead band range. The switch
operation is described in the following example.
(1) When the high-temperature sensor senses that the temperature has dropped
below point A, the lower dead band limit, the channel switches from the high-
temperature sensor to the low-temperature sensor.
(2) When the high-temperature sensor senses that the temperature has risen to
between point A, the lower dead band limit, and point B, the higher dead band
limit, the controller calculates the value between the low-temperature sensor and
the high-temperature sensor. The ratio of the high-temperature sensor varies
between 0% at point A and 100% at point B.
(3) When the high-temperature sensor senses that the temperature has risen above
point B, the higher dead band limit, the channel switches from the low-tempera-
ture sensor to the high-temperature sensor.
(4) When the high-temperature sensor senses that the temperature has dropped
below point C and is going towards point D, the controller calculates the value
between the low-temperature sensor and the high-temperature sensor.
®
! ®
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CH1
CH2
OFF ON
Nothing
OFF ON
Nothing
Nothing
OFF ON
Nothing
OFF ON
CH1
CH1
CH1
CH2 CH2
CH2
5-35
