Honeywell Searchline Excel Cross-Duct, Техническое руководство

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MAN0530 Issue 09 October 03 Searchline Excel
2104M0506
6. PROBLEM SOLVING
Fault/Problem Causes Remedies
No signal or Receiver misaligned Re-align the Receiver, first using the telescope and then using
very low signal the Interrogator.
at Receiver
Transmitter misaligned
Re-align the Transmitter using the telescope.
The beam path has become Check that the beam path is clear from Transmitter to
obscured Receiver.
Remove any obstruction if present.
No output from Transmitter
1) Check that the Transmitter is flashing. When viewed
on the axis, an orange flash can be seen coming from
the Transmitter.
Alternatively, listen for a distinct ticking sound when the
lamp flashes.
Note: The infrared beam is invisible and eye safe.
2) If the Transmitter is not flashing, check that the +24V
supply is reaching the Transmitter correctly.
Unit does not Plastic test filters are only an
Searchline Excel units are calibrated on real gas.
respond exactly approximate simulation of
This results in a variation of the response of different Excel
as expected to gas
units to plastic test filters. See section 5.1.2.
test filters
1) Check that the response to the test filters is within the
limits stated in this handbook. See section 5.1.2.
2) Check that the value being used for response testing
corresponds correctly to the target gas that the unit has
been calibrated for.
Receiver misaligned 1) Use the telescope and Interrogator to optimise
Receiver alignment.
2) Re-zero unit.
Contamination of windows
1) Check the Transmitter and Receiver windows for build
up of contamination. Clean windows if required. See
Chapter 5
.
2) Re-zero unit.
Drift of unit’s zero position 1) Verify that there is no gas in the beam path.
2) Re-zero the unit.
Unit appears to Misinterpretation of INHIBIT , Searchline Excel does not report negative gas readings on
be reporting a BEAM-BLOCK or LOW the 4-20mA.
negative gas SIGNAL currents that are 1) Configure controller/PLC to interpret and present
reading on the output on the 4-20mA currents below 4mA correctly,
4-20mA or ,
2) Familiarise operators with the interpretation of sub-
4mA output currents from Excel as follows:
FAULT 0mA
INHIBIT 2mA
BEAM-BLOCK 2.5mA*
LOW SIGNAL 3mA*
or,
3) Reconfigure the INHIBIT , BEAM-BLOCK and LOW
SIGNAL currents output by the Excel unit.