YOKOGAWA EXAxt ZR22G, Руководство пользователя, Страница: 191 / 211

<12. Troubleshooting>
12-10
IM 11M12A01-02E 16th Edition : Mar. 19, 2020-00
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Alarm 11: Thermocouple Voltage Alarm
This alarm is generated when the emf (voltage) of the thermocouple falls below -5 mV (about
-170°C) or exceeds 42.1 mV (about 1020°C). Whenever Alarm 11 is generated, Error2 (heater
temperature failure) occurs.
(1) Breakage of the heater thermocouple signal wire between the converter and the detector
occurred, or the cable is not securely connected to the connecting terminals.
(2) The positive and negative poles of the heater thermocouple signal wiring are shorted out in
the wiring extension or at the connection terminals.
(3) A failure of the thermocouple at the detector heater assembly occurred.
(4) A failure of the electrical circuits inside the converter occurred.
<Locating cause of failure, and countermeasures>
(1) Stop the power to the converter.
(2) Remove the wiring from terminals 3 and 4 of the detector and measure the resistance
between these terminals. If the resistance value is 5 Ω or less, the thermocouple seems to
be normal. If it is higher than 5 Ω, it may indicate the possibility that the thermocouple has
broken or is about to break. In this case, replace the heater unit (refer to Section 11.1.3,
Replacement of the Heater Unit).
CAUTION
Measure the thermocouple resistance value after the difference between the detector tip
temperature and ambient temperature falls to 50°C or less. If the thermocouple voltage is large,
accurate measurement cannot be achieved.
(3) If the thermocouple is normal, check whether or not the wiring cable is broken or shorted
out, and also whether the wiring cable is securely connected to the terminals.
Also check that the wiring resistance between the converter and the detector is 10 Ω or less.
(4) If there is no failure in the wiring, the electrical circuits inside the converter may possibly fail.
Contact the service personnel at Yokogawa.
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Alarm 12: Input Current Alarm
When “mA-input” is selected in the Exhaust gas setup display, this alarm occurs if the current
input from the temperature transmitter goes outside he range from 3.2 to 21.6 mA.
If this alarm occurs simultaneously with Alarm 9: Exhaust Gas Temperature Alarm, first solve
the problem for Alarm 9. If Alarm 12 occurs independently, the cable connection between this
equipment and the temperature transmitter may be improper (disconnected).
<Locating cause of failure, and countermeasures>
(1) Check that cable connections (including connecting lugs) are proper.
(2) If the cable connections are correct, display the exhaust gas temperature and check that it
matches the temperature transmitter’s temperature signals. If mismatched, check whether
the transmitter output range meets the Exhaust gas setup of this equipment.
(3) If the range setting is correct, the analyzer electronics may be defective. In such a case,
contact your local Yokogawa service or sales representative.
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Alarm 13: Battery Low Alarm
An internal battery is used as backup for the clock. After this alarm occurs, removing power from
the instrument may cause the clock to stop but should not affect stored parameters. The internal
clock is used for blow back scheduling; if you use this then after a battery alarm occurs (until the
battery is replaced) be sure to check / correct the date and time every time you turn on the power.