Bosch Rexroth EFC 3600, Operating Instructions Manual, Page: 170 / 238

● In the tables, the recommended resistance of the brake resistor is 100
% braking torque, selected according to necessity. If the actually nee‐
ded torque is not 100 %, the resistance of the brake resistor in the table
should be adjusted in inverse proportion, i.e. how much the brake tor‐
que increases based on 100 %, the resistance of the brake resistor
should decrease by the same amount, vice versa.
● When selecting brake resistor R
b
, make sure the current I
c
which flows
through the resistor is less than the current output ability of the brake
unit. The current I
c
through the brake resistor can be calculated by for‐
mula I
c
=U
d
/R
b
, in which U
d
is the braking operating voltage of brake
unit.
● After the adjustment of the resistance of brake resistor, the power of
brake resistor should be also adjusted appropriately. The power can be
calculated by formula P
max
=U
d
2 / R
b
. According to the actual working
condition, the braking ratio OT % can be selected to reduce the power
of brake resistor reasonably for intermittent braking load. The power of
brake resistor can be calculated by formula P
R
=K * P
max
* OT %, in
which k is the derating coefficient of brake resistor. The selection of the
brake torque should be in general smaller than 150 % of the rated mo‐
tor torque, or consulting the technical support for more information.
Bosch Rexroth AG
Accessories
DOK-RCON03-EFC-3600***-IT01-EN-P
Rexroth Frequency Converter EFC 3600
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