Parker AC890 Product Manual page 90

Calculation
Brake resistor assemblies must be rated to absorb both peak braking power during deceleration and the
average power over the complete cycle.
Peak braking power P
Average braking power P
Obtain information on the peak power rating and the average power rating of the resistors from the resistor
manufacturer. If this information is not available, a large safety margin must be incorporated to ensure that
the resistors are not overloaded.
By connecting these resistors in series and in parallel the braking capacity can be selected for the
application.
IMPORTANT The minimum resistance of the combination and maximum dc link voltage must be as specified in
Appendix E: "Technical Specifications" - Internal Dynamic Brake Switch.
890SD (Standalone) Drive: Frame G, H & J
 J  
2
0 0055 . ( n n
1 2

pk
t
b
P
pk

x t
av
t
b
c
2
)
( ) W
J - total inertia (kgm
n - initial speed (rpm)
1
n - final speed (rpm)
2
t - braking time (s)
b
t - cycle time (s)
c
Associated Equipment
)
2
5-4
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