Chapter 8
7-segment display
7
8
, Change override
lamp
a2
, alternating
a3
, alternating
a4
, alternating
a5
, alternating
a6
, alternating
a7
, alternating
e
f1
f4
or
,
alternating
f2
f5
or
,
alternating
Tab. 8-1: Troubleshooting table for the safety evaluation unit LE 20 and LE 20 Muting
1
) Clear monitoring area and muting area, respectively (by way of override pushbutton or manually)
2
) Cut operating voltage and restore
3 1 6
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Troubleshooting
8
Troubleshooting
The LE 20 evaluation unit monitors itself during operation:
When the device is switched on, it performs a self-test in which
the electronic components are checked.
If a fault is detected during the self-test, the device displays an
error message on the 7-segment display and stops the hazar-
dous process.
Meaning
Override lamp faulty or - if
no override lamp
connected - override
function active (start
possible with override
pushbutton)
External device monitoring
fault
Faulty photoelectric switch,
invalid configuration
Override time-out
Override time-out fault
Concurrence time exceeded
3 seconds
Starting/stopping sequence
of muting photoelectric
switches faulty
Both muting lamps are faulty Wiring fault, lamp burnt out
System error
Overcurrent at OSSD 1 or
OSSD 2
OSSD 1 or OSSD 2 has short-
circuit with 24 V
Cause/Check
Check override lamp, if fitted.
If the override function is
active the monitored area
must be free once
momentarily within 30
minutes so that the LE 20
does not switch to OFF.
EDM input not wired or
contactors do not release
Check wiring,
check TEST/NON input
Override time elapsed
Override active longer than
30 minutes
Muting sensor faulty,
object moving too slowly
Muting sensor faulty
Switch operating voltage off
and on again
Check wiring between OSSD
1 and OSSD 2
Check wiring between OSSD
1 and OSSD 2
Operating Instructions
Safety Evaluation Unit LE 20
Remedy/Action
Change override lamp,
Check wiring, check
2
contactors,
)
Correct wiring,
test safety photoelectric
switches at the sensor,
Correct wiring, check
photoelectric switches
Check layout of muting
1
2
sensors,
),
)
Check object movement,
check muting sensors,
Check layout of muting
1
sensors,
)
Change both lamps,
Change device
Measure current consumption
(max. 500 mA),
2
)
Correct short-circuit,
8 008 685/Q913/2007-05-21
1
2
),
)
2
)
1
)
1
2
),
)
2
)