aci B5C, Installation, Operation And Maintenance Manual

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B5C Operation And Maintenance Manual
85950-301-000 RA Aug. 05, 2016 24
5. Troubleshooting
This troubleshooting guide is intended as an aid in identifying the cause of unexpected
behavior and determining whether the behavior is due to normal operation or an internal
or external problem.
SYMPTOMS PROBABLE CAUSE SUGGESTED SOLUTION
RS-485
RX LED or
TX LED constantly ON

RS-485 bus connection has a
problem

RS-485 driver U6 is damaged

Controller side RS-485 driver
has problem

Disconnect the cable to isolate
the problem

Replace U6 IC on main board

Replace the RS-485 driver on
the controller
No response to gas

Sensor screen is dirty

Sensor has expired

Clean sensor opening

Replace smart sensor assembly,
see Replacement Parts
Apparent false alarm 
Puff of gas

Not properly calibrated

Solvent fumes or interference
from high levels of interfering
gas

Radio frequency interference

Monitor is functioning

Recalibrate

Remove source of interfering
gas

Check that grounding and
shielding is correct