Mitsubishi Heavy Industries FDT71VNXVD Service Manual page 12

(u) External input/output control (CnT)
Be sure to connect the wired remote controller to the indoor unit. Without wired remote controller remote operation by CnT is
not possible to perform.
Optional
1
2
XR1
CnT 3
XR2
Blue
4
12V XR3
5
XR4
6
XR5
1) Output for external control (remote display)
Following output connectors (CnT) are provided on the indoor control PCB for monitoring operation status.
① Operation output: Outputs DC12V signal for driving relay during operation
② Heating output: Outputs DC12V signal for driving relay during heating operation
③ Thermostat ON output: Outputs DC12V signal for driving relay when compressor is operating.
④ Error output: Outputs DC12V signal for driving relay when anomalous condition occurs.
2) Remote operation input
Remote operation input connector (CnT-6) is provided on the indoor control PCB.
However remote operation by CnT-6 is not effective, when "Center mode" is selected by center controller.
In case of plural unit (twin, triple, double twin), remote operation input to CnT-6 on the slave indoor unit is invalid.
Only the "LEVEL INPUT" is acceptable for external input, however when the indoor function setting of "Level
input (Factory default)" or "Pulse input" is selected by the function for "External input" of the wired remote controller,
operation status will be changed as follows.
a) In case of "Level input" setting (Factory default)
Input signal to CnT-6 is OFF→ON ...... unit ON
Input signal to CnT-6 is ON→OFF ...... unit OFF
Operation is not inverted.
Note: The latest operation has priority
It is available to operate/stop by remote controller or center controller
b) In case of "Pulse input" setting (Local setting)
It is effective only when the input signal to CnT-6 is changed OFF→ON, and at that time unit operation [ON/OFF] is
inverted.
CnT-6 input
Unit A
Unit B
① Operation output
② Heating output
③ Thermostat ON output
④ Error output
⑤ Remote operation input
ON
OFF
CnT-6 input
ON
Unit A
OFF
ON
Unit B
ON
OFF OFF
ON
OFF
ON
OFF
-
(CnT-2: XR1)
(CnT-3: XR2)
(CnT-4: XR3)
(CnT-5: XR4)
(CnT-6: No-voltage contactor)
ON
OFF OFF
ON
OFF
OFF
ON
OFF
OFF
ON
OFF
OFF
ON
-
12
'10 • PAC-SM-137A