Heater Disconnection Detection Function (Available For The Q64Tcttbw, Q64Tcrtbw Only) - Mitsubishi Electric MELSEC Q Series User Manual

3 SPECIFICATIONS
3.2.7 Heater disconnection detection function (available for the Q64TCTTBW,
Q64TCRTBW only)
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(1) Heater disconnection detection function
(a) This is a function to check if there is a heater wire breakage using the
reference heater current value (load current value detected by the current
sensor (CT)), when the transistor output is on.
(b) The heater disconnection detection function compares the current values of
reference heater and heater disconnection alert, and determines that there is
a heater wire breakage when the current value of reference heater is below
that of heater disconnection alert.
However, when the transistor turned-on time is less than 0.5 seconds, the
heater disconnection detection is not performed.
(c) By restoring the disconnection, Alert definition (buffer memory address: 5
8 ) turns off the disconnection detection.
H
However, when setting CT monitor method switching (buffer memory
address: B0
off unless the heater turns on ("OUT" LED on the front of the module is lit).
The timing of turning on the heater differs according to Control output period
setting (buffer memory address: 2F
(d) The following shows setting procedures for the heater disconnection
detection function.
1) Set current sensor (CT) to be used to CT selection (buffer memory
address: 110
2) Set CT input to be assigned for each channel to CT input channel
assignment setting (buffer memory address: 108
3) Monitor the Heater current process value (buffer memory address:
100
is on.
4) Set a value monitored in 3) to Reference heater current value (buffer
memory address: 118
5) Set a value to judge whether to perform heater disconnection detection
and output off-time current error detection by percent (%) of the
reference heater current value in the Heater disconnection alert setting
(buffer memory address: 3A
6) Set 1 (ON current) in CT monitor method switching (buffer memory
address: B0
7) Set whether to use the heater disconnection compensation function in
the Heater disconnection compensation function selection (buffer
memory address: AA
8) Set the number of consecutive occurrences of heater disconnection
detection that becomes a trigger to give an alert in the Heater
disconnection/output off-time current error detection delay count
(buffer memory address: A6
POINT
Although standard setting value of the heater disconnection alert setting of *1 is
80%, variation of the current value may be increased depending on operating
status or characteristics of the heater. Fully make sure that no problem occurs in
the actual system.
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) to "1: ON current", the disconnection detection does not turn
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to 117 ).
H H
to 107 ) and check a value of current that flows while the heater
H H
to 11F
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, 5A
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) when not to detect current error while the output is OFF.
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).
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).
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MELSEC-Q
, 4F , 6F , 8F ).
H H H
to 10F
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).
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, 7A , 9A ). 1
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to
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).
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