Contents Of This Chapter - ABB ACS880-07 Hardware Manual

Resistor braking

Contents of this chapter

This chapter tells how to select, protect and wire brake choppers and resistors. The
chapter also contains the related technical data.
Operation principle and hardware description
The drive can be equipped with an optional built-in brake chopper (+D150). Brake
resistors are available as add-on kits or factory installed (+D151).
The brake chopper handles the energy generated by a decelerating motor. During the
deceleration, motor generates energy back to the drive and the voltage in the drive
intermediate DC link starts to rise. The chopper connects the brake resistor to the
intermediate DC circuit whenever the voltage in the circuit exceeds the limit defined by the
control program. Energy consumption by the resistor losses lowers the voltage until the
resistor can be disconnected.
Planning the braking system
Selecting the brake circuit components

1. Calculate the maximum power generated by the motor during braking (P
2. Select a suitable drive, brake chopper and brake resistor combination for the
application from the rating table on page 256. The braking power of the chopper must
be greater or equal than the maximum power generated by the motor during the
braking.
3. Check the resistor selection. The energy generated by the motor during a 400-second
period must not exceed the heat dissipation capacity of the resistor (E
Resistor braking 251
16
).
max
.
R)