Troubleshooting
NAR300 system for high temperature
42
Hauser
Prior to performing an alarm operation check, take preemptive measures to ensure that
the alarm system will not be impacted even if an oil leak alarm is activated. Refer to the
previous section "Operation check flow diagram" for how to perform an operation check.
The following diagram shows the voltage check point that was described in the flow
diagram.
A
FG
H-
H+
TB1
TB2
FRAME GUARD
PROBE
FEL+
FEL-
A0039874
25
Intrinsically safe terminal box
A
Sensor I/F Ex box
H- Blue
H+ Blue
FEL+Red
FEL- Blue
7.3.2
Transmitter/alarm system problems
Item
Description
LED is lit red: Normal
alarm activation
An alarm is activated even if the sensor voltage has not been detected. Replace the
transmitter if there is no problem with the wiring between the transmitter and the
sensor I/F Ex box.
LED is lit green: There is
no alarm signal from the
sensor
If an alarm has been activated under this condition, investigate the resistance
values of the transmitter's alarm output terminal in the following order:
1.
Turn off the power supply to the alarm activation system.
2.
Disconnect the alarm output wire from the transmitter.
3.
Check to ensure that the LED is continuously lit green.
4.
Measure the resistance between 1: COM and NO and 2: COM and NC. The
transmitter is normal if 1: 0 Ω (short) and 2: several MΩ or higher (open).
Otherwise, replace the transmitter.
LED is not lit: The
transmitter is not turned
on
If there is rated voltage between terminal L and N on the transmitter, replace the
transmitter. If the voltage cannot be measured between the L and N terminals,
check the power supply or the power cable.
