Baumuller BM4400 - Page 110

Additional data referring to water-cooled brake resistors
Instruction handbook b maXX BM4400, BM4600, BM4700
Document No.: 5.12008.07 Baumüller Nürnberg GmbH
110
of 358
3.6
Example for the calculation of BM4446
Device type Peak
power
P
Smax
3)
Continuous
power
P
Dmax
2) 3)
Constants
for calculation
C
1
C
2
C
3
BM4446-ZIX/FIX-XXXXXR10 61 kW 1.5 kW 0.2 K/W 0.01605 K/Ws -0.9169 s
-1
Technical data see brake resistors on ZPage 106–.
n =5, see brake cycle ZFigu
re 51– on page 108
P
S
t
on
t
off
P
S_1
= 20 kW < 61 kW t
on_1
= 0.15 s < 1 s t
off_1
= 1.11 s
P
S_2
= 13 kW < 61 kW t
on_2
= 0.15 s < 1 s t
off_2
= 1.79 s
P
S_3
= 20 kW < 61 kW t
on_3
= 0.15 s < 1 s t
off_3
= 6.85 s
P
S_4
= 23 kW < 61 kW t
on_4
= 0.15 s < 1 s t
off_4
= 1.85 s
P
S_5
= 24 kW < 61 kW t
on_5
= 0.15 s < 1 s t
off_5
= 5.65 s
T
cycle
= = 5 0.15s + 1.11s + 1.79s + 6.85s + 1.85s + 5.65s = 18 s
P
D
=
= 0.417 kW = 417 W < P
Dmax
< 1.5 kW internal brake resistor can be used
T
M
= P
0
C
1
= 417 W 0.2 K/W = 83.4 K
Start value: T
0
= P
0
C
1
= 417 W 0.2 K/W = 83.4 K
T
1
= T
0
+ C
2
P
s_1
t
on_1
= 83.4 K + 0.01605 K/Ws 20 000 W 0.15 s = 131.55 K
T
2
=
= = 132.1 K
t
on_n
t
off_n
1
n

+
1
n

D
1
2
---
P
s_1
t
ein_1
+ ......+ P
s_n
t
off_n

T
cycle
-------------------------------------------------------------------------------------------------------

1
2
---
20kW 13kW 20kW 23kW 24kW++++015s
18s
-----------------------------------------------------------------------------------------------------------------------------------
==
T
1
T
M
–e
C
3
t
off_1

 T
M
C
2
P
s_2
t
on_2
++=
131
·
,55K 83,4K–e
0,9169s–
1–
1,11s
 83,4K 0,01605K/Ws 13000W 0,15s++=