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13. Troubleshooting
If any malfunctions occur, refer to the following items after checking that power is being
supplied to the controller.
13.1 Indication
Problem
Possible Cause and Solution
[
], nothing or PV
is indicated on the PV
Display.
• Control output OFF function is working.
Press the
key for approx. 1 second to release the
function.
[
] is flashing on
the PV Display.
• Burnout of thermocouple, RTD or disconnection of DC
voltage (0 to 10 mV DC, -10 to 10 mV DC, 0 to 50 mV DC,
0 to 100 mV DC, 0 to 1 V DC)
Change each sensor.
How to check whether the sensor is burnt out
[Thermocouple]
If the input terminals of the instrument are shorted, and if a
value around room temperature is indicated, the instrument
is likely to be operating normally, however, the sensor may
be burnt out.
[RTD]
If approx. 100 of resistance is connected to the input
terminals between A-B of the instrument and between B-B
is shorted, and if a value around 0 (32 ) is indicated,
the instrument is likely to be operating normally, however,
the sensor may be burnt out.
[DC voltage (0 to 10 mV DC, -10 to 10 mV DC, 0 to 50 mV
DC, 0 to 100 mV DC, 0 to 1 V DC)]
If the input terminals of the instrument are shorted, and if
a scaling low limit value is indicated, the instrument is likely
to be operating normally, however, the signal wire may be
disconnected.
• Check whether the input terminals of thermocouple, RTD or
DC voltage (0 to 10 mV DC, -10 to 10 mV DC, 0 to 50 mV
DC, 0 to 100 mV DC, 0 to 1 V DC) are securely mounted to
the instrument input terminal.
Connect the sensor terminals to the instrument input
terminals securely.
[
] is flashing on
the PV Display.
• Check whether input signal wire for DC voltage (1 to 5 V DC)
or direct current (4 to 20 mA DC) is disconnected.
How to check whether the input signal wire is disconnected
[DC voltage (1 to 5 V DC)]
If the input to the input terminals of the instrument is 1 V DC
and if a scaling low limit value is indicated, the instrument is
likely to be operating normally, however, the signal wire
may be disconnected.
[Direct current (4 to 20 mA DC)]
If the input to the input terminals of the instrument is 4 mA
DC and if a scaling low limit value is indicated, the
instrument is likely to be operating normally, however, the
signal wire may be disconnected.
• Check whether input signal wire for DC voltage (1 to 5 V DC)
or direct current (4 to 20 mA DC) is securely connected to
the instrument input terminals.