Restart protection, Reset of the mains failure control, Function library – Lenze EVS9332xS User Manual
Page 172

Function library
Function blocks
3.2.40
Mains failure control (MFAIL)
3−120
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EDSVS9332S−EXT EN 2.0
3. Increase of the deceleration time or reduction of the brake torque (see Fig. 3−104) is only
possible with restrictions:
– An increase of the acceleration time MFAIL T
ir
(C0982) reduces the initial brake torque and
increases the deceleration time.
– Increasing the integral−action time MFAIL T
n
(C0981) decreases the braking torque and
simultaneously increases the deceleration time. If C0981 contains too high integral−action
times, the controller runs into the LU threshold before speed 0 is reached. Thus, the drive is
not controlled anymore.
4. Re−establish possibly required signal connections to the outputs of the controller (terminals
X6).
)
Note!
All settings must be saved non−volatile in a parameter set under C0003.
3.2.40.3
Restart protection
The integrated restart protection is to avoid a restart in the lower speed range, after the supply voltage
was interrupted for a short time only (mains recovery before the drive has come to standstill).
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How to protect the drive from restart is explained in chapter 3.2.40.2.
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Go to C0472/18 and enter the threshold in [%] of nmax (C0011) if you do not want an
automatic restart below this threshold after mains recovery.
– Speed at mains recovery < threshold in C0472/18: Drive is continued to be braked in a
controlled way. This function can only be completed by MFAIL−RESET = HIGH.
– Speed after mains recovery > threshold in C0472/18 Drive accelerates to its setpoint along
the set ramps.
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The function is deactivated by:
– C0472/18 = 0 % or
– C0975 = 1000 (FIXED0% to MFAIL−THRESHLD)
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Reset with MFAIL−RESET = HIGH
– is required after every mains connection
– is displayed by MFAIL−STATUS = HIGH, if MFAIL−FAULT = LOW
3.2.40.4
Reset of the mains failure control
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The mains failure control is reset with MFAIL−RESET = HIGH (in the example with terminal
X5/E5).
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The reset pulse is always required if:
– the restart protection is active.
– the restart protection is used and the supply (mains or DC supply) was switched on.