Siemens SINAMICS S120 Function Manual page 419

Automatic restart during active essential service mode
● The converter ignores the settings in p1206 (faults without automatic restart) and works
with the setting "restart after a fault with further start attempts" (p1210 = 6).
● The converter carries out the maximum number of restart attempts set in p1211
corresponding to the settings in p1212 and p1213. If these attempts are not successful,
then the converter goes into a fault condition with F07320.
Speed setpoint when the essential service mode is active
● p3881 specifies the speed setpoint. If you have defined an analog input as setpoint
source using p3881, then for wire breakage, the converter can switch over to setpoint
p3882.
● Wire-break monitoring can only take place with a setting as current input at the analog
inputs of the CU310-2 and the TM31. Wire-break monitoring cannot take place with a
setting as voltage input in essential service mode, thus there is no switchover to the
alternative setpoint p3882.
Interaction between bypass and the essential service mode
● If, when activating the essential service mode, bypass operation is active, converter
operation is selected internally in order to ensure that the setpoint is entered via the
source intended for the essential service mode.
● If faults are still present after the number of start attempts parameterized in p1211, then
the converter goes into a fault condition with F07320. In this case, there is an option of
switching over to bypass operation and then directly connecting the motor to the line
supply.
Behavior with active speed limitations
In essential service mode, the adjustable speed setpoint of the ESM source observes the
settings of active speed limitations:
● If the set ESM speed is less than the minimum speed, the minimum speed is effective in
essential service mode.
● The settings of the skip frequency bands and maximum speeds are observed.
Automatic switchover in the event of an encoder fault to encoderless operation
With corresponding parameter assignment (p0491 = 1 or p0491 = 5) the essential service
mode can even be maintained in the event of an encoder fault. If an encoder error occurs
while ESM is active, the drive changes to encoderless control to maintain emergency
operation.
Drive functions
Function Manual, 11/2017, 6SL3097-4AB00-0BP5
7.26 Extended service mode for CU310-2 connected to blocksize power units
Basic functions
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