Siemens SINAMICS G120 Operating Instructions Manual page 246

Advanced commissioning
6.11 Essential service mode
The inverter blocks all functions that switch off the motor to save energy, e.g. PROFIenergy
or hibernation mode.
Unexpected exiting of the essential service mode by selecting "Safe Torque Off"
The PM240‑2 and PM240P‑2, FSD ... FSF Power Modules provide terminals for selecting
the "Safe Torque Off" (STO) safety function. An active STO function switches the motor off
and so terminates essential service mode. The termination of essential service mode can
cause severe injury or death, e.g. for the failure of a flue gas extraction.
● Set both STO switches to the "OFF" position on the PM240‑2 or PM240P‑2, FSD ... FSF
Reaction to faults during active essential service mode
In "essential service mode", the inverter does not switch off the motor when faults develop,
but rather reacts differently depending on the fault type:
● The inverter ignores faults, which do not directly result in the destruction of the inverter or
the motor.
● The inverter attempts to automatically acknowledge faults, which cannot be ignored, using
the automatic restart function.
● For faults that cannot be acknowledged, it is possible to switch over the motor to line
operation using the bypass function.
Automatic restart during active essential service mode
The inverter 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 inverter 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 inverter goes
into a fault condition with F07320.
Speed setpoint during active essential service mode
P3881 specifies the setpoint. If you have defined an analog input as setpoint source using
p3881, then for wire breakage, the inverter can switch over to setpoint p3882.
Interaction for bypass and essential service mode
● If, when activating the essential service mode, bypass operation is active, inverter 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 inverter 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.
246
WARNING
Power Module.
Converter with the CU230P-2 Control Units
Operating Instructions, 09/2017, FW V4.7 SP9, A5E34257946B AE