Lenze EVS9332xS - Manual (Page 171)

Function library
Function blocks
3.2.40 Mains failure control (MFAIL)
3−119
l
EDSVS9332S−EXT EN 2.0
Fine setting
t
UG
t1 t2
Abschaltschwelle LU
Abschaltschwelle OU
Einschaltschwelle Bremseinheit
t
n
0
0
Ansprechschwelle
CMP2-OUT
MFAIL-DC-SET
t3
Fig. 3−104 Schematic with different brake torques
t = t1 Mains failure
t = t2 Zero speed with higher braking torque (short adjustment time)
t = t3 Drive reaches the LU switch−off threshold with lower brake torque (higher adjustment time)
without reaching speed 0
t > t3 Drive is no longer controlled (is braked by friction)
Repeat the following steps several times.
1. Obtaining a very low final speed before the controller reaches the undervoltage threshold LU:
– Increasing the proportional gain MFAIL V
p
(C0980).
– Decreasing the integral−action time MFAIL T
n
(C0981).
2. Avoid activation of the brake unit or the overvoltage threshold:
– Increasing the integral−action time MFAIL T
n
(C0981) until the characteristic in Fig. 3−103 is
almost reached.
– Reduce additionally the setpoint of the DC bus voltage at the input MFAIL−DC−SET (in the
example C0472/19), if necessary.