Siemens SINAMICS S120 Function Manual page 414

Basic functions
8.27 Essential service mode (ESM) for CU310-2 on Blocksize power units
Signal p3880 = 0 deactivates the essential service mode:
● If one of the OFF1, OFF2 or OFF3 commands is active, the converter switches off the motor.
● If neither OFF1, OFF2 nor OFF3 is active, the converter switches the speed setpoint from
the "ESM setpoint source" to the normal setpoint source.
Special features of the essential service mode
The essential service mode (ESM) is characterized by the following features:
Use other signals to switch on and switch off the motor when the essential service mode is
active
Unexpected exiting of the essential service mode by selecting "Safe Torque Off"
PM240‑2 Power Modules have terminals to select the "Safe Torque Off" (STO) safety
function. An active STO function switches the motor off, thus terminating the essential service
mode. The termination of essential service mode can cause severe injury or death, e.g. as
smoke and associated gases are no longer extracted.
● Set both STO switches to the "OFF" position on the PM240‑2 Power Modules.
The OFF1, OFF2 and OFF3 commands for switching off the motor have no effect.
The inverter blocks all functions that switch off the motor to save energy, e.g. PROFIenergy or
hibernation mode.
Response to faults when the essential service mode is active
In the "essential service mode", the converter does not switch off the motor when faults
develop, but instead responds differently depending on the fault type:
● The converter ignores faults, which do not directly result in the destruction of the converter
or the motor.
● The converter 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 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.
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WARNING
Function Manual, 06/2019, 6SL3097-5AB00-0BP2
Drive functions