Siemens SINAMICS S150 NEMA, Operating Instructions Manual

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Functions, monitoring and protective functions
9.3 Drive functions
Enclosed Drives
578
Operating Instructions, 12/2018, A5E36652151A
Bypass as a fallback strategy
If the converter fails due to an internal, non-acknowledgeable fault, essential service mode is
no longer possible. In this case, the motor can be operated via the controller in bypass mode
in the event of converter failure. For this purpose, bit 7 of the status word for the automatic
restart (r1214.7) must be interconnected with p1266.
The bypass function must also be activated without synchronization (p1260 ≠ 3), and the
changeover source for the bypass must be set to "Bypass via signal (BI: p1266)"
(p1267.0 = 1).
You must ensure that r1214.7 is also set, otherwise there will be no changeover to the line
supply. To end the bypass mode, the essential service mode must be deactivated. There is
no switchover to converter operation (drive coasts down).
Automatic switchover to encoderless operation for encoder faults
By automatically pre-assigning parameter p0491 (motor encoder fault response ENCODER)
with the value "1", then the drive maintains the emergency service mode even when there is
an encoder fault.
In addition, setting values "5" or "6" can be used. These setting values are lost after a power
interruption at the Control Unit – or when the drive restarts. After this, the drive continues to
operate with automatic pre-assignment (p0491 = 1).
WARNING
Pending drive standstill in the essential service mode (ESM)
As a result of the automatic drive switchover to encoderless operation, controlled starting of
the drive after a power interruption can fail, in spite of the fact that the automatic restart
function (AR) is activated. If the drive comes to a standstill, then this can cause severe
injury or death, e.g. for ventilation and smoke extraction systems.
•
To avoid the motor coming to a standstill, when the essential service mode (ESM) is
activated, switchover the drive to encoderless operation.
Display of activations/faults of essential service mode
The number of activations and the errors that occurred during essential service mode are
displayed in parameter r3887:
● r3887[0]: Number of activations of essential service mode
● r3887[1]: Number of faults during essential service mode
The counter statuses in r3887 can be reset with p3888 = 1.
Function diagrams
FP 3040 Setpoint channel - Direction limitation and direction reversal
FP 7033 Technology functions - Essential service mode (ESM)