Lenze EMB9352−C - Manual (Page 87)

Dimensioning
Dimensioning examples
Complex movement
5
l
87 EDBMB935X DE/EN/FR 13.0
Step 1: Calculate brake resistance
R
B
+
U
DC
2
P
gen,max
+
(725 V) 2
61.25 kW
+ 8.58 W
Step 2: Determine the number of brake resistors
Three brake resistors are selected with 22
W each which are connected in
parallel.
ƒ Please observe the rated power when dimensioning the brake resistors. It
results from the average braking power of a machine cycle.
Step 3: Calculate the number of brake choppers per brake resistor
N
Brm
+
P
gen,ave
(3s)
N
R
@ P
N
(U
DC
)
+ 36.875 kW
3 @ 10 kW +
1.23 å 2
Every one of the three brake resistors requires two brake choppers.
Alternative: Four brake resistors with 33 W each:
N
Brm
+
P
gen,ave
(3s)
N
R
@ P
N
(U
ch
)
+ 36.875 kW
4
@ 10 kW +
0.92 å 1
The four brake resistors only require one brake chopper each.
)
Note!
Technically, both solutions are possible. Please check the solutions
for cost effectiveness.