IDEC MicroSmart Pentra - Manual (Page 146)

T ROUBLESHOOTING
FC5A MicroSmart PID Module User’s Manual FC9Y-B1283 8-5
Input Status Checking
Sensor may be burnt out if any of the following problems occur.
(1) Operating status over range flag remains ON.
(2) Operating status under range flag remains ON.
(3) Input value constantly shows 0mA or 0V.
Please make sure these conditions are checked thoroughly and take the appropriate action.
(1) Operating status over range flag remains ON.
Checking Items Action
Is thermocouple or resistance
thermometer burnt out? Is voltage
input (0 to 1V DC) disconnected? Replace sensor.
[How to check sensor burn out or voltage disconnection]
[Thermocouple]
Short the input terminals of the PID module. If a value around
room temperature is indicated, the PID module is operating
normally and the sensor may be burnt out.
[Resistance thermometer]
Connect a pprox. 100Ω resistor between the input terminals A
and B, and short the input terminals B and B of the PID module.
If a value around 0°C (32°F) is indicated, the PID module is
operating normally and the sensor may be burnt out.
[Voltage (0 to 1V DC)]
Short the input terminals of the PID module. If a linear
conversion minimum value is indicated, the PID module is
operating normally and the signal wire may be disconnected.
(2) Operating status under range flag remains ON.
Checking Items Action
Does the input signal source for voltage (1
to 5V DC) or current (4 to 20mA) operate
normally? Check the input signal source for voltage (1 to 5V DC) or current
(4 to 20mA).
[How to check whether the input signal wire is disconnected]
[Voltage (1 to 5V DC)]
Input 1V DC to the input terminals of the PID module. If a linear
conversion minimum value is indicated, the PID module is
operating normally and the signal wire may be disconnected.
[Current (4 to 20mA)]
Input 4mA to the input terminals of the PID module. If a linear
conversion minimum value is indicated, the PID module is
operating normally and the signal wire may be disconnected.
(3) The process variable (PV) constantly shows the linear conversion minimum value.
Checking Items Action
Does the input signal source for voltage (0
to 5V DC, 0 to 10V DC) or current (0 to
20mA) operate normally? Check input signal source for voltage (0 to 5V DC or 0 to 10V DC)
or current (0 to 20mA).
[How to check whether the input signal wire is disconnected]
[Voltage (0 to 5V DC or 0 to 10V DC)]
Input 1V DC to the input terminals of the PID module. If a
converted value, calculated with the linear conversion minimum
and maximum values, corresponding to 1V DC is indicated, the
PID module is operating normally and the signal wire may be
disconnected.
[Current (0 to 20mA)]
Input 4mA to the input terminals of the PID module. If a
converted value, calculated with the linear conversion minimum
and maximum values, corresponding to 4mA is indicated, the
PID module is operating normally and the signal wire may be
disconnected.