Honeywell Searchline Excel Cross-Duct, Техническое руководство

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78
MAN0530 Issue 09 October 03 Searchline Excel
2104M0506
6. PROBLEM SOLVING
Fault/Problem Causes Remedies
Electrical installation
1) Check that the +24V supply is reaching the unit.
problem
Voltage at the unit should be b18V and +32V.
2) Check cables and connections to the unit, especially
the 4-20mA loop connections.
3) Check that the unit has the correct type of 4-20mA
output for use with the controller that it is connected to.
Heavy contamination of Check the Transmitter and Receiver windows for build up of
optics contamination. Clean the windows if required. Re-zero unit.
Very low visibility along
1) Check that the Transmitter can be seen from the
beam path due to dense fog,
Receiver. If Transmitter can be seen, even with some
blizzard or sand-storm
difficulty, low visibility is unlikely to be the problem.
conditions
2) If the Transmitter cannot be seen from the Receiver,
very low visibility could be the problem. Wait until
visibility improves and verify that the unit then
returns to operational status.
Output is 2.5mA
.
Beam path is blocked
Check that the beam path is clear from the Transmitter to
(BEAM BLOCK) Receiver. Remove any obstruction if present.
Transmitter or Receiver 1) Connect SHC1 Interrogator to unit and check signal
misaligned levels.
2) If signal levels are low, use the telescope and SHC1
Interrogator to optimise Receiver alignment.
3) If signal levels remain low after re-aligning Receiver,
check the Transmitter alignment using the telescope.
4) Re-zero the unit after alignment. See Appendix A.5.3.4.
Output is 3mA Heavy contamination of Check the Transmitter and Receiver windows for build up of
(LOW SIGNAL) optics contamination. Clean windows if required. Re-zero the unit.
Transmitter or Receiver 1) Use the telescope and Interrogator to optimise
misaligned Receiver alignment.
2) If signal levels remain low after re-aligning Receiver,
check the Transmitter alignment using the telescope.
3) Re-zero the unit after alignment. See Appendix A.5.3.4.
Output is 2mA Unit has been inhibited by Release output from INHIBIT state using SHC1 Interrogator.
(INHIBIT) the Interrogator
Unit executing power-up 1) Wait for 1 minute. When power-up routine is completed
routine satisfactorily the unit s output should exit the INHIBIT
state.
2) If unit remains in INHIBIT , check the +24V supply is
reaching the unit. If the voltage is below +18V or is
fluctuating above and below +18V, the unit may be
being prevented from completing power-up. (This is an
electrical installation problem.)