Monitoring Functions; Earth Fault; Internal Earth-Fault Monitoring When Using A Current Measuring Module Or A 1St Generation Current / Voltage Measuring Module - Siemens SIMOCODE 3UF Programming And Operating Manual

Monitoring Functions

9.1

Earth Fault

9.1.1 Internal earth-fault monitoring when using a current measuring module or a 1st
generation current / voltage measuring module
Internal earth-fault monitoring via current measuring modules or current / voltage measuring
modules is only possible for motors with a 3-phase connection in networks that are either
grounded directly or with low impedance. You can activate internal ground-fault monitoring
by parameterization.
It covers two different operating conditions:
● Normal operation to 2x I
current I
● Start-up or overload operation to 2x I
the set current I
detected.
NOTICE
False tripping in the case of internal ground-fault monitoring
False tripping can occur if you use internal earth-fault monitoring for star-delta circuits.
During delta operation, the residual current is non-zero due to harmonics.
Response to internal earth-fault monitoring
Deactivated, signaling, warning, tripping
Delay
Setting range: 0 - 25.5 s (0.5 s)
Activity
Unless deactivated, this function is always active, regardless of whether the motor is running
or not (operating state "ON").
SIMOCODE PRO V PN FDI
Programming and Operating Manual, 05/2020, A5E44499659002A/RS-AA/001
. The actual operating current must be less than twice the set
s
. Fault currents of > 30 % of the set current l
s
. Residual currents of >15 % of the effective motor current will be
s
will be detected.
s
. The actual operating current is greater than twice
s
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