6 Technical Data
6.9 Braking resistances
DC1…20… and DC1…OE1 Variable Frequency Drives
02/20 MN040059EN
www.eaton.com
173
6.9 Braking resistances
Figure 86:
Examples of DX-BR… brake resistor designs
The following tables provide examples of DX-BR… brake resistors rated for
individual DC1 variable frequency drives. They are specified based on the
“high duty” and “low duty” classification for intermittent braking with a cycle
time t
C
of 120 seconds and a pulse power P
Peak
equal to maximum braking
power P
max
of the variable frequency drive with the rated motor output.
Load groups (simplified classification)
•
Low duty
: Low load with short braking duration and low duty factor
(up to about 25 %), e.g., for horizontal conveyors and handling
equipment for bulk cargo and general cargo, end carriages, sliding doors,
and turbomachinery (centrifugal pumps, fans).
•
High duty
: High load with long braking duration and high duty factor
(at least 30 %), e.g., for elevators, downhill conveyors, winders,
centrifuges, flywheel motors, and large fans.
NOTICE
The specified minimum resistance R
Bmin
must not be fallen
below.
CAUTION
Brake resistors get extremely hot during operation!
1
2
T1
T2
