6 Specifications
6.9 Braking resistors
DA1 Variable Frequency Drives
08/18 MN04020005Z-EN
www.eaton.com
183
6.9 Braking resistors
Figure 104:Examples of DX-BR… braking resistor designs
The following tables provide examples of DX-BR… braking resistors rated for
individual DA1 variable frequency drives. They are specified according to the
“High duty” and “Low duty” classification, for intermittent braking, with a
cycle time t
C
of 120 seconds, corresponding to a pulse power P
Peak
, which
corresponds to the maximum braking output 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.
WARNING
The resistor value must not be less than the specified minimum
resistance R
Bmin
CAUTION
Braking resistors get extremely hot during operation!
1
2
T1
T2