Lenze EVS93 Series, System Manual

Page: 236 / 386

Function library
Function blocks
3.2.62 Mains failure control (MFAIL)
3−208
l
EDSVS9332K−EXT EN 4.0
3. Increase of the deceleration time or reduction of the brake torque (see Fig. 3−157) is only
possible with restrictions:
– An increase of the acceleration time MFAIL T
ir
(C0982) reduces the initial brake torque and
simultaneously increases the deceleration time.
– Increasing the reset time MFAIL T
n
(C0981) decreases the braking torque and
simultaneously increases the deceleration time. If C0981 contains too high reset times, the
controller runs into the LU threshold before speed 0 is reached. Thus, the drive is not
controlled anymore.
4. If required, relink the signals to the outputs of the controller (terminals X6).
)
Note!
All settings must be saved non−volatilely in a parameter set under C0003.
3.2.62.3 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).
l
How to protect the drive from a restart is explained in chapter 3.2.62.2.
l
In C0472/18 you can enter the threshold in [%] of nmax (C0011) below which you do not want
the drive to restart.
– Speed at mains recovery < threshold in C0472/18: Drive is continued to be braked in a
controlled way. This function can only be terminated by MFAIL−RESET = HIGH.
– Speed after mains recovery > threshold in C0472/18 Drive accelerates to its setpoint along
the set ramps.
l
The function is deactivated by:
– C0472/18 = 0 % or
– C0975 = 1000 (FIXED0% to MFAIL−THRESHLD)
l Reset with MFAIL−RESET = HIGH
– is required after every mains connection
– is displayed by MFAIL−STATUS = HIGH, if MFAIL−FAULT = LOW
3.2.62.4 Reset of the mains failure control
l
The mains failure control is reset with MFAIL−RESET = HIGH (in the example with terminal
X5/E5).
l
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.