Function
16
CMD420_421-DM_D00224_01_M_XXEN/08.2016
or falls below the release value (response value plus hysteresis), the alarm
LEDs go out. With the fault memory activated, the alarm relays do not change
their actual state until the reset button R is pressed.
3.2.1 Window discriminator function
This operating can be used to monitor the measured current for two response
values overcurrent and undercurrent.
This operating mode (In) can be selected from the SEt menu.
Changing the operating mode of the current monitoring device, overcurrent
mode (Hi), undercurrent mode (Lo) or window mode (In) changes the me-
aning of the alarm LEDs AL1 and AL2:
3.2.2
Automatic self test
The device automatically carries out a self test after connecting to the system
to be monitored and later every 24 hours. During the self test internal functio-
nal faults will be detected and appear in form of an error code on the display.
3.2.3
Manual self test
After pressing the test button for > 1.5 s, the device carries out a self test. Du-
ring this test, internal functional faults are detected and will be displayed in
form of an error code. The alarm LEDs are checked during this test. While hol-
ding down the test button T, all device-relevant display elements appear on
the display.
Communi-
cation mode
LED lights
Meaning
HI
AL1
Prewarning overcurrent (>I)
AL2
Alarm overcurrent (>I)
Lo
AL1
Prewarning undercurrent (<I)
AL2
Alarm undercurrent (<I)
In
AL1
Alarm undercurrent (<I)
AL2
Alarm overcurrent (>I)