Diagnostics And Troubleshooting; Troubleshooting - Siemens SITRANS L LCS100 Operating Instructions Manual

Diagnostics and troubleshooting

8.1

Troubleshooting

LEDs
Green Yellow
Power Signal
supply output
OFF OFF
ON ON or OFF
ON ON or OFF
ON ON or OFF
ON OFF
ON Blinks
for a few
times,
then
stops
blinking
ON OFF
ON ON or OFF
ON ON or OFF
59
Behaviour
White Probe
cov-
ered/uncovered
OFF
ON Probe is uncovered but
LED white states cov-
ered
OFF Probe is covered but LED
white states uncovered
ON or OFF Yellow LED lights oppo-
site to white LED when
this is not meant to
happen
Blinks slowly (eve- Relay = idle
ry 2 seconds)
ON or OFF Blinking happens after
the potentiometer was
turned
Blinks fast (twice Current loop = 3.6mA,
per second) Relay = idle
ON or OFF No respond (change of
white and yellow LED)
when potentiometer is
turned and probe is
uncovered
ON or OFF Unequal current in cur-
rent loop
Cause
Proper power supply
not
applied to device
Connector came loose
Defective component in
device
Sensitivity is set too
high. Either sensitivity
setting not properly
done or too much ma-
terial buildup
Sensitivity is set too
low. Either sensitivity
setting not properly
done or too low dielec-
tric constant from ma-
terial.
Incorrect polarity on
power supply
Potentiometer is on the
clockwise stop position
and thus the 4-20mA
continuous mode is
active.
This is a normal
operation. The blinking
indicates the position of
the potentiometer after
it
was turned.
Diagnostics has indicat-
ed a failure
Defective component in
device
Loop circuitry is con-
nected against earth
SITRANS LCS100 2-wire mA and Relay Version
Operating Instructions, 05/2023, A5E52142831-AA
8
Action
Check power supply
Refasten connector
Contact distributor
Reduce sensitivity (see
Operating elements
(LEDs) (Page 39)). If
applicable clean probe
from buildup
Increase sensitivity (see
Operating elements
(LEDs) (Page 39)). Die-
lectric constant of mate-
rial must be 1.5 or more
Reverse polarity on
power supply. See Out-
put logic (Page 30).
If the switch mode is
required, go to
switchpoint setting (see
Operating elements
(LEDs) (Page 39))
No action required
Contact distributor
Contact distributor
Remove earth connec-
tion from loop circuitry