Lenze i750 User Manual

Braking oper
aon
If more regenerave power is generated in an inverter in the DC system than can be stored in
the DC bus of the inverter, this excess energy is used by the other inverters in the DC-bus
connecon.
If there are operang states in which excess regenerave energy is generated for the enre
DC-bus connecon, an addional brake resistor must be used at the supplier. This avoids the
disconnecon of the DC-bus connecon due to too high DC-bus voltage. The excess energy is
converted into heat in the brake resistor.
NOTICE
Overheang of the br
ake resistor due to overload
Possible consequences: Destrucon of the brake resistor or the supplier.
▶
If you use non-intrinsically safe brake resistors: If the thermal contact responds, the voltage
supply to the supplier must be disconnected (e.g. switch o the control of the mains
contactor).
▶
Use intrinsically safe brake resistors.
Precondions f
or trouble-free braking operaon
•
Check whe
ther sucient braking power is available from the brake chopper in the supplier
for the maximum regenerave power occurring in all operang states.
•
When designing for connuous braking power in the DC bus, the liming monitors must be
included:
•
Monitoring the brake chopper
•
Monitoring the brake resistor
•
Increasing the braking power:
•
You can use several suppliers with brake chopper and brake resistor in parallel.
•
One supplier must be dened as "master", all other suppliers as "slave".
•
Adjust the wiring of the control terminals to ensure simultaneous switching of all brake
choppers on request of the master:
Connect the digital input DI3 of each slave to GND potenal.
Connect the digital output DO1 of the master with DI1 of the slaves.
X20.2 X20.2
DO1DO2GD
X20.1
DI1DI2
DI3
Master
Slave
|
DC 24 V
(.19.2...+28.8V)
DI1DI2
DI3
DO1DO2GD
X20.1
Fig. 5: Master-slave wiring of the brake chopper with suppliers connected in parallel
Informaon on pr
oject planning
DC-bus connecon
Braking operaon
39

Lenze i750 Specifications

General

Brand	Lenze
Model	i750
Category	Inverter
Language	English