Dimensioning Of Brake Resistor - BONFIGLIOLI Agile Operating Instructions Manual

Parameter descriptions

7.10.4.1 Dimensioning of brake resistor

WARNUNG
Connect a brake resistor following the instructions and safety information provided in
chapter 5.6.5 "Brake resistor".
The following values must be known for dimensioning:
− Peak braking power P
− Resistance R in Ω
b
− Relative operation time OT in %
Calculation of peak braking power P
•
(
2
J ⋅ n − n
1 2
P
=
b Peak
182 ⋅ t
b
• Calculation of resistance R
2
U
d BC
R =
b
P
b Peak
The switch-on threshold U
switch-on threshold can be set via parameter
CAUTION
The resistance of the brake resistor must not be less than the minimum value R
10%. The values for R
If the calculated resistance R
resistance must be selected.
Calculation of relative operation time OT
•
t
b
O = T
t
c
In the case of infrequent short braking operations, typical values of the relative operation time OT are
at 10%, for long braking operations (≥ 120 s) typical values are at 100%. In the case of frequent
deceleration and acceleration operations, it is recommended that the relative operating time OT be
calculated according to the above formula.
The calculated values for P
the resistor-specific permanent power.
Special functions
in W
b Peak
b Peak
P = Peak braking power in W
b Peak
J = Moment of inertia of drive system in kgm
)
n = Speed of drive system before the braking operation in
2
1
min
n = Speed of drive system after the braking operation in
2
min
t = Braking time in s
b
b
R = Resistance in Ω
b
U = Switch-on threshold in V
dBC
P = Peak braking power in W
b Peak
is the DC link voltage at which the brake resistor is switched on. The
d BC
Trigger Threshold
are listed in chapter 11 "Technical data".
b min
of the brake resistor is between two standard series values, the lower
b
OT = Relative operation time (percentage duty cycle)
t = Braking time (duty cycle)
b
t = Cycle time
c
, R and OT can be used by the resistor manufacturers for determining
b Peal b
-1
-1
506.
Example:
t = 48 s, t = 120 s
b c
t
b
O T = = 0 4 . = 40
t
c
243
06/2013
2
b min
%
Agile
Operating Instructions
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