NORD Drivesystems BU0750 - Manual (Page 119)

7.7 Extra functions
BU 0750 GB-3311 Subject to technical amendments 119
Parameter Setting value / Description / Note
Parameter
set
Available with option
P554 Min. chopper trigger point Always visible
65 … 100 % With this parameter it is possible to program a manual (peak) power limit for the brake resistor. The
switch-on delay (modulation level) for the chopper can only rise to a certain maximum specified limit.
Once this value has been reached, the inverter switches off the current to the resistor, irrespective of
the level of the link voltage.
The result would be an overvoltage switch-off of the FI.
P555 Chopper power limit Always visible
5 ... 100 %
[ 100 ] With this parameter it is possible to program a manual (peak) power limit for the brake resistor. The
switch-on delay (modulation level) for the chopper can only rise to a certain maximum specified limit.
Once this value has been reached, the inverter switches off the current to the resistor, irrespective of
the level of the link voltage.
The result would be an overvoltage switch-off of the FI.
P556 Brake resistor Always visible
3 ... 400

[ 120 ]
Value of the brake resistance for the calculation of the maximum brake power to protect the resistor.
IOnce the maximum continuous output (P557) has been reached, then an I 2 t limit error (E003) is
triggered.
P557 Brake resistor power Always visible
0.00... 100.00 kW
[
0
.00 ]
Continuous resistor output (nominal power) for the calculation of the maximum braking power.
0.00 = Monitoring disabled
P558 Magnetizing time P Always visible
0/ 1/ 2...500 ms
[ 1 ] The ISD control can only function correctly if there is a magnetic field in the motor. For this reason, a
DC current is applied before starting the motor. The duration depends on the size of the motor and is
automatically set in the factory setting of the FI.
For time-critical applications, the magnetizing time can be set or deactivated.
0 = Switched off
1 = Automatic calculation
2...500 = corresponding to set value
Note: Values that are too low can reduce the dynamics and torque development during start-up.
P559 DC run-on time P Always visible
0.00 ... 5.0 s
[ 0.50 ] Following a stop signal and the braking ramp, a direct current is briefly applied to the motor to fully
bring the drive to a stop. Depending on the inertia, the time for which the current is applied can be
set in this parameter.
The current level depends on the previous braking procedure (current vector control) or the static
boost (linear characteristic).
P560 EEPROM storage Always visible
0 ... 1
[ 1 ] 0 = Changes to the parameter settings will be lost if the FI is disconnected from the mains
supply.
1 = All parameter changes are automatically written to the EEPROM and remain stored there
even if the FI is disconnected from the mains supply.
NOTE: If USS communication is used to implement parameter changes, it must be ensured that
the maximum number of write cycles (100,000 x) in the EEPROM is not exceeded.
7.8 PosiCon
For the description of parameter P6xx please refer to the instruction manual BU 0710.
These parameters are only visible if the option SK XU1-POS PosiCon positioning is used.