BONFIGLIOLI Agile User 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
b Peak
in W
− Resistance R
b
in Ω
− Relative operation time OT in %
• Calculation of peak braking power P
b Peak
( )
b
2
2
2
1
Peak b
t182
nnJ
P
⋅
−⋅
=
P
b Peak
=
Peak braking power in W
J
=
Moment of inertia of drive system in kgm
2
n
1
=
Speed of drive system before the braking operation in
min
-1
n
2
=
Speed of drive system after the braking operation in
min
-1
t
b
=
Braking time in s
• Calculation of resistance R
b
Peak b
2
BC d
b
P
U
R =
R
b
=
Resistance in Ω
U
dBC
=
Switch-on threshold in V
P
b Peak
=
Peak braking power in W
The switch-on threshold U
d BC
is the DC link voltage at which the brake resistor is switched on. The
switch-on threshold can be set via parameter
Trigger Threshold 506.
CAUTION
The resistance of the brake resistor must not be less than the minimum value R
b min
-
10%. The values for R
b min
are listed in chapter 11 "Technical data".
If the calculated resistance R
b
of the brake resistor is between two standard series values, the lower
resistance must be selected.
• Calculation of relative operation time OT
c
b
t
t
TO =
OT
=
Relative operation time (percentage duty cycle)
t
b
=
Braking time (duty cycle)
t
c
=
Cycle time
Example:
t
b
= 48 s, t
c
= 120 s
%404.0
t
t
TO
c
b
===
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
b Peal
, R
b
and OT can be used by the resistor manufacturers for determining
the resistor-specific permanent power.
243
Special functions 06/2013 Operating Instructions
Agile

BONFIGLIOLI Agile Specifications

General

Brand	BONFIGLIOLI
Model	Agile
Category	DC Drives
Language	English