Zero Servo; Zero Servo Function Description - INVT Goodrive350-19 Series Operation Manual

Goodrive350-19 series VFD for crane
Function
code
Torque limit 1 in open-loop
P90.41
P90.42 Torque setting for brake release
Brake closing delay after stop
P90.44

5.12 Zero servo

5.12.1 Zero servo function description

The zero servo function needs to be used in closed-loop vector control. During stop, the VFD checks
whether the pulse value is greater than P93.05. If yes, the VFD reports the brake failure alarm, and
the output can be set through the relay. After the brake failure alarm protection input delay specified
by P93.06 (if the pulse value is greater than triple the zero servo tolerance pulse threshold specified
by P93.05 within the period, the delay specified by P93.06 is skipped), if P93.02=1 (Zero servo input
slows down), the VFD runs downward slowly at the frequency specified by P93.03, and it coasts to
stop when the slow lowering hold time specified by P93.04 is reached. Then the VFD performs
Name
vector control
DC braking starts
Description
The limit is specified by P90.41.
2: Torque/speed switchover mode 1
(boost with braking)
It is used when P90.04=1 since the
brake is involved. When the brake is
opened, the speed mode is
automatically used.
3: Torque/speed switchover mode 2
(horizontal moving)
Since the brake is not involved, the
torque/speed switchover is set
through P90.44. The set frequency
needs to be greater than P90.44.
Setting range: 0.0–300.0% (of the
motor rated current)
(P90.40=1 Torque limit mode)
0.0–200.0%
During the running, when the torque
feedback value is equal to or greater
than P90.42, brake release timing is
entered.
(It is valid only when P90.04=1, which
indicates the brake is controlled by
the VFD, and the VFD uses the
torque mode.)
0.00–50.00HZ
Used in torque/speed switchover
mode 2
-85-
Commissioning guidelines
Setting
120.0%
50.0%
8.00Hz