YOKOGAWA ZR22G User Manual page 224

(3) If the resistance value is within the range, the cold junction temperature sensor is
considered normal. Check that the wiring cable is not broken or short-circuited and that it
is securely connected to the terminal. Also check that the wiring resistance between the
transmitter and sensor is 10 Ω or less.
(4) If the wiring is correct, the electrical circuit inside the transmitter may be faulty.
Contact our service.
(8) Alarms 207 and 208: Thermocouple voltage alarm
Generated when the electromotive force of the thermocouple drops below-5 mV (approx.-
170°C) or exceeds 42.1 mV (approx. 1020°C). When alarm 207, 208 occurs, alarm 017 (heater
temperature error) is always generated.
• The heater TC signal wire between the converter and the detector is broken, or the cable is
not securely connected to the connection terminal.
• The positive and negative poles of the heater thermocouple signal wiring are shorted out in
the wiring extension or at the connection terminals.
• Defective thermocouple of sensor heater
• Converter internal electrical circuit error
<Searching for the cause of the error and remedy>
(1) Disconnect the power supply to the converter.
(2) Remove the wires from terminals 3 and 4 of the detector and measure the resistance
between terminals 3 and 4. If the resistance is 5 Ω or less, the thermocouple is considered
normal. If the resistance is greater than 5 Ω, the wire may be broken or disconnected.
Replace the heater assembly in this case (see section: "11.1.4
Heater Unit").
CAUTION
Measure the resistance of the thermocouple after the difference between the tip of the detector
and the ambient temperature is 50°C or less. If the electromotive force of the thermocouple is
large, it cannot be measured accurately.
(9) Alarms 209 and 210:AI current high and low alarm
If "External input" is selected in "Setting the measured gas pressure" or "Setting the measured
gas temperature", this occurs when the input current from the pressure or temperature
transmitter (hereinafter referred to as transmitter) deviates from the range of 3.8 to 20.5 mA. If
this alarm comes out at the same time as alarms 211 to 214 (pressure/temperature input alarm),
Take action for alarms 211 to 214. If alarms 209 and 210 are occurring independently, the cable
between the converter and the transmitter may be broken.
<Searching for the cause of the error and remedy>
(1) Check the cable status, including the connection terminals.
(2) If there is no problem with the cable connection, display the measured gas pressure/
temperature in the "Detailed Data Display".
Check that this pressure/temperature matches the signal from the transmitter. If the
pressure/temperature is incorrect, check that the output range of the transmitter matches
the "input temperature setting" of the tester.
(3) If there is no problem with the range setting, it is probable that the device's electrical circuit is
faulty. Please consult our service.
<12. Troubleshooting>
Replacement of the
IM 11M12G01-02EN 1sh Edition : Mar. 25, 2021-00
12-9