Automatic Restart" Function After Power Failure - Siemens Sinamics G120 CU240E Operating Instructions Manual

Functions
5.10 Technological functions
5.10.2.2

"Automatic restart" function after power failure

Restart after a power failure and/or faults within a few seconds.
This function is particularly useful when the frequency converter is operated as a stand-alone
device.
The "automatic restart" function is used to restart the drive automatically once the power has
been restored following a power failure. All faults are acknowledged automatically and the
drive is switched on again.
Line undervoltage or power failure
The term "line undervoltage" describes a situation in which the line voltage fails momentarily
and is then restored. The power failure is so short that the 400V power supply of the
frequency inverter is briefly interrupted, but the electronics power supply is still maintained.
The term "power failure" describes a situation in which the power fails for a longer period,
whereby the DC link collapses completely and the Control Unit of the converter is in a zero-
current state.
An ON command prior to the power failure and when the system is powered-up is required
for the "automatic restart" function.
Since the function is not restricted to line supply faults, it can also be used to automatically
acknowledge faults and restart the motor after any tripping. To allow the drive to be switched
to a motor shaft that is still rotating, the "flying restart" function must be activated via P1200.
When the "automatic restart" function is active (P1210 > 1), a motor can restart
automatically once the power has been restored. This is particularly critical if it is incorrectly
assumed that the motors have been shut down after a long power failure.
For this reason, death, serious injury, or considerable material damage can occur if
personnel enters the working area of motors in this condition.
Automatic restart mode
Table 5- 43
P1210 = 0: Disable automatic restart
automatic restart inactive
P1210 = 1: acknowledge all faults without automatic restart
When P1210 = 1, any faults that are present are acknowledged automatically once the cause has
been rectified. If more faults occur once the previous faults have been acknowledged, these are also
acknowledged automatically. If the ON/OFF1 signal (control word 1, bit 0) is set to HIGH, a period of
P1212 + 1s must elapse between when a fault is acknowledged and another one occurs. If the
ON/OFF1 signal is set to LOW, the time between when a fault is acknowledged and another one
occurs must be at least 1 s.
When P1210 = 1, fault F07320 is not generated if the attempt to acknowledge the fault is
unsuccessful (e.g. due to frequent faults).
140
WARNING
Automatic restart mode
Frequency inverter
Operating Instructions, 08.10. 2008, t.b.d.