Siemens SCALANCE XR524-8C Operating Instructions Manual page 21

Meaning in display mode D
In display mode D, the "L1" and "L2" LEDs indicate whether the power supply is monitored.
Table 3- 3
LED color
-
Green
Table 3- 4
LED color
-
Green
SCALANCE XR-500
Operating Instructions, 05/2014, A5E03275845-05
Monitoring for devices with 24 VDC
L1/L2 LED L1/L2 connector
LED status
Off Power supply is not monitored.
If the power supply falls below 17 VDC, the signaling contact does
not respond.
On Power supply is monitored.
If the power supply falls below 17 VDC, the signaling contact
responds.
Monitoring for devices with 100 to 240 VAC
L1/L2 LED L1/L2 connector
LED status
Off Power supply is not monitored.
If the power supply falls below 90 VAC, the signaling contact does
not respond.
On Power supply is monitored.
If the power supply falls below 90 VAC, the signaling contact
responds.
Description of the device
3.3 LED display
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