Lenze 9212, Operating Instructions Manual, Page: 57 / 86

53
4.1.2. Setting
These setting instructions are meant as guideline and must not
always decelerate the machine to standstill before reaching the
undervoltage threshold. The parameter setting of the codes, which
influences the DC-bus control during mains failure detection (C079,
C080, C228, C236, C237), depend on the size of the drive
configurations and the mechanical features of the system.
There are minimum speeds at which the energy of the mechanical
system is not high enough to compensate the losses which occur
during the controlled deceleration (switched-mode power supplies,
inverter, machines).
Aim:
•
The aim is to have a controlled speed deceleration that allows a
DC-bus voltage value which remains higher than the
undervoltage threshold for as long as possible.
As soon as the value falls below this threshold, pulse inhibit will
be set and the drive will coast to standstill.
•
The brake chopper should not be activated during the controlled
deceleration of the speed.
Therefore, the parameter setting of the DC-bus control should
be "softly". It is not very important whether the DC-bus can be
loaded to the voltage set under C236.
Required measuring units:
•
Oscilloscope,
at least 2 channels, if possible with memory.
Test set-up:
•
Connect channel 1 of the oscilloscope with X5,62 of the axis
module (speed monitor).
•
Connect channel 2 of the oscilloscope with X3,2 of the supply
module (DC-bus monitor).
•
If available, connect channel 3 of the oscilloscope with X5,44 of
the axis module (RDY-output).
Presettings:
1. Set the speed controller of the axis module drive configuration
as usual.
2. Activate the mains failure detection of the master drive (C229 =
-1-).
If the function is activated, the RDY-output changes from the
HIGH level to the LOW level. As soon as the speed is
decelerated to 0, the RDY-output re-changes to HIGH.
3. The relevant codes must be set as follows:
Code Presetting
C079 -1-
C080 150 s
C228 1/10...1/20 of the natural slow-down time of the machine at
maximum operating speed
C229 -1-
C236 680 V
C237 1000 rpm or more