8.4.1 Under-Voltage during Power-Up
In this case the voltage level is high enough for the
encoder box to boot and load the firmware correctly, but
the voltage level is not high enough to ensure that a
power failure can be handled correctly.
The under-voltage during power-up is detected with a
timeout of 5 seconds and the encoder box displays “Err1”.
To reset this error, apply the correct supply voltage of 24 V
and carry out a power cycle.
130BD095.10
Err1
1
Power
on
16 V
>18 V
max. 5 s
2
Illustration 8.1 Under-Voltage during Power-Up
1
Power up and normal operation
2
Under-voltage during power-up, “Err1” shown on display
Table 8.1 Legend to
8.4.2 Sudden Voltage Drop
If the supply voltage suddenly drops, the encoder box will
log the event, close the log file on the SD card, and send a
voltage emergency message. If the drop is not enough to
shut down the encoder box, it remains in a state where
the voltage level is verified continuously in order to detect
a possible voltage rise. If a voltage rise is detected, an
internal reset is issued.
130BD096.10
1
2
>18 V
3
Illustration 8.2 Voltage Drop
1
Log event, send emergency message, close log
2
Wait for voltage rise
3
Internal reset
Table 8.2 Legend to
8.4.3 Power Failure
In this case the voltage drop to <18 V means a power
failure, in which case the encoder box will log the event,
close the log file on the SD card, and send a voltage
emergency message.
1
2
>18 V
130BD097.10
Illustration 8.3 Power Failure
1
Log event, send emergency message, close log
2
Power failure
Table 8.3 Legend to
Faults
VLT
®
ISD Encoder Box Operating Instructions
26
MG75F102 - VLT
®
is a registered Danfoss trademark
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