Bosch Rexroth VFC 610 Series Operating Instructions Manual page 26

Bosch Rexroth AG
Brake Chopper Overview
Brake pow- Brake chopper
er (KW) type code
75
FEAE07.1-VA2-
NNNN
90
Tab. 4-3: Type selection of brake resistor
The recommended resistance of the brake resistor is 100 % brak-
●
ing torque, selected according to necessity. If the actually needed
torque is not 100 %, the resistance of the brake resistor in the ta-
ble should be adjusted in inverse proportion, i.e. how much the
braking torque increases based on 100 %, the resistance of the
brake resistor should decrease by the same amount, vice versa.
When selecting brake resistor R
●
flows through the resistor is less than the current output ability of
the brake chopper. The current I
be calculated by formula I
operating voltage of brake chopper.
After the adjustment of the resistance of brake resistor, the power
●
of brake resistor should be also adjusted appropriately. The pow-
er can be calculated by formula P
actual working condition, the braking ratio ED % can be selected
to reduce the power of brake resistor reasonably for intermittent
braking load. The power of brake resistor can be calculated by for-
mula P
of brake resistor. The selection of the braking torque should be in
general smaller than 150 % of the rated motor torque, or consult
the technical support for more information.
When ED>10 %, the master / slave control mode is recommended
●
(see
or consult the technical support.
20/65
Brake resistence(Ω)
Number of
brake
Recom-
choppers
mended
value
1 13.6
1
= k × P × ED %, in which 'k' is the derating coefficient
R max
chapter 9.2.2 "Master / Slave Control Mode" on page
Power of brake resis-
Recom-
Min. value mended
value
≥5 9.60
20 ≥5 6.00
, make sure the current I
b
through the brake resistor can
c
= U / R , in which U
c d b
= U 2
max d
DOK-RCON04-VFC*BRAKE**-IT01-EN-P
Brake Chopper
Number of
tor(KW)
paralleled
brake re-
Min. value
sistors
≥9 2
≥10 3
which
c
is the braking
d
/ R . According to the
b
48),