Troubleshooting - Panasonic KT7 Instruction Manual

Heater burnout alarm (option), Loop break alarm and Alarm utilize common output terminals.
This option cannot be applied to DC current output type.
Rating
Setting range : 5A, 0.0 to 5.0A (Off when set to 0.0)
Setting accuracy:
Action
Output
Serial communication (option)
The following operations can be carried out from the external computer.
(1) Reading and setting of SV, PID and various set values
(2) Reading of the PV and action status (3) Change of the functions
Cable length
Communication interface
Communication method
Communication speed
Parity
Stop bit
Communication protocol
Connectable number of units : Maximum 31 units to 1 host computer
Communication error detection: Parity, checksum (LRC, CRC)

12. Troubleshooting

If any malfunctions occur, refer to the following items after checking the power supply to the controller.
12.1 Indication
Problem
PV display is indicating
[ ].
[ ] is flashing on the
PV display.
[ ] is flashing on the
PV display.
: 5A, 10A, 20A, 50A (Must be specified)
20A, 0.0 to 20.0A (Off when set to 0.0)
5% of the rated value
: ON/OFF action
: Open collector, Control capacity, 24V DC 0.1A (Max.)
: Max. communication distance 1000m, Cable resistance; Within 50
: EIA RS-485
: Half-duplex communication start-stop synchronous
: 2400, 4800, 9600, 19200bps (Selectable by keypad)
: Even, Odd and No parity (Selectable by keypad)
: 1, 2 (Selectable by keypad operation)
: Modbus RTU, Modbus ASCII (Selectable by keypad)
• Control output OFF function is working.
Press the
• Burnout of thermocouple, RTD or disconnection of DC voltage (0 to 1V 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
between A-B of the instrument and between B-B is shorted, and
if a value around 0
be operating normally, however, the sensor may be burnt out.
[DC voltage (0 to 1V 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 1V DC) are securely mounted to the instrument input terminal.
Connect the sensor terminals to the instrument input terminals securely.
• Check whether input signal source for DC voltage (1 to 5V DC) or
DC current (4 to 20mA DC) is disconnected.
How to check whether the input signal wire is disconnected
[DC voltage (1 to 5V DC)]
If the input to the input terminals of the instrument is 1V 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.
[DC current (4 to 20mA DC)]
If the input to the input terminals of the instrument is 4mA 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 5V DC) or DC current
(4 to 20mA DC) is securely connected to the instrument input terminals.
• Check if polarity of thermocouple or compensating lead wire is correct.
• Check whether codes (A, B, B) of RTD agree with the instrument terminals.
10A, 0.0 to 10.0A (Off when set to 0.0)
50A, 0.0 to 50.0A (Off when set to 0.0)
Presumed cause and solution
key for approx. 1 second to release the function
of resistance is connected to the input terminals
(32 ) is indicated, the instrument is likely to
19
.