Operating instructions
Functions
5.10 Technological functions
CU240S and CU240E Control Units, FW 3.2
130 Operating Instructions, 03/2009, A5E02440075B AA
● Dynamic braking
–
Advantages:
defined braking characteristics; no additional motor temperature
increase; constant braking torque; in principle, also functions when the power fails
–
Disadvantages:
A braking resistor is required; braking energy is lost as heat; the
permissible load of the braking resistor must be taken into account
● Regenerative braking
–
Advantages:
Constant braking torque; the regenerative energy is not converted into
heat, but is regenerated into the line supply; can be used in all applications;
continuous regenerative operation is possible - e.g. when lowering a crane load
–
Disadvantage:
Does not function when power fails
5.10.1.1 DC and compound braking
Application areas for DC braking and compound braking
DC braking and compound braking are typically used for applications in which the motor is
normally operated at a constant speed and is only braked down to standstill in longer time
intervals, e.g. centrifuges, saws, grinding machines and conveyor belts.
Operating characteristics of DC braking
_I_
3
U
%LW
3
3
W
W
W
W
2))
2))2))
21
2))
'&EUDNLQJ
'&EUDNLQJDFWLYH
Figure 5-9 DC braking after an OFF1 or OFF3 command