17
Detecting Gas Saving Lives
English
6. Fault finding
6.1 Errors signalled by LED
LED Pattern
Detector Status
Action
Regular flash each second.
Healthy.
On with short blips off.
Detector in start-
up mode.
Wait 10 seconds.
Fast flash on and off or
irregular flash pattern.
Supply voltage
too low or too
high.
Ensure the
IRmax
supply voltage is
correctly set. Ensure measurement
is made directly at the detector
terminals.
Permanently on.
Fault, host or
i-module error.
Power-cycle the
IRmax
, if fault
persists, return to
Crowcon
.
Two long flashes followed
by a short flash.
Fatal error; lamp
or detector fault.
Return to
Crowcon
.
Fast double flash each
second.
Fatal error,
module or
configuration
fault.
Check the detector configuration
using PC communications kit
software.
Check power supply.
If fault persists, return to
Crowcon
.
Short blip each second.
Optics obscured.
Check window and mirror, clean if
necessary. Re-zero
IRmax
and check
calibration.
Any other faults can only be rectif
i
ed by returning the
IRmax
to
Crowcon
or authorised
service agent.
6.2 Analogue Output
IRmax
will remain in Fault state and “Service required” will also be shown on the
IR Display
(if fitted) if the analogue output signal has failed or is not connected to a
control system or load resistor.
IRmax
actively monitors the 4-20mA analogue output
signal to verify it is in range. If the signal is out of range the detector will go into fault
and the output will be set to 1mA. Thus, when testing a detector it is essential that it is
either connected to a control panel or a 100
Ω
load resistor is connected between the ‘0V’
and ‘Sig’ terminals (detector set to ‘Source’ mode) or between the ‘0V’ and ‘+V’ terminals
(detector set to ‘Sink’ mode).
