9
05.01
9.4 Application examples
9-366
©
Siemens AG 2012 All Rights Reserved
SIMODRIVE 611 Configuration Manual (PJU) – 02/2012 Edition
Table 9-13
Determining MTTF
d
Parameter
Value
Comment
Channel 1
Safety relay –K1
B
10d
value
20.000.000
Manufacturer’s data
n
op
24972 per years
24960 per year by the protective door + 12 per
year by EMERGENCY STOP
MTTF
d
(–K1)
8008 years
MTTF
d
=
B
10d
0,1 x n
op
Contactor relay –K6
B
10d
value
1.333.333
Manufacturer’s data
n
op
24972 per year
24960 per year by the protective door + 12 per
year by EMERGENCY STOP
MTTF
d
(–K6)
534 years
MTTF
d
=
B
10d
0,1 x n
op
Intermediate result, channel 1
MTTF
d
(channel 1)
501 years
Capped to 100
years
MTTF
d
(Channel 1)
1
MTTF
d
(–K1, –K6)
1
=
∑
Channel 2
Line contactor –K2
B
10d
value
1.333.333
Manufacturer’s data
n
op
12 per year
12 actuations per year as a result of
EMERGENCY STOP
MTTF
d
(–K2)
1.111.111 years
MTTF
d
=
B
10d
0,1 x n
op
Auxiliary contactors –K3, –K4 and –K5
B
10d
value
1.333.333
Manufacturer’s data
n
op
24972 per year
24960 per year by the protective door + 12 per
year by EMERGENCY STOP
MTTF
d
(contactor
relay)
534 years
MTTF
d
=
B
10d
0,1 x n
op
Intermediate result, channel 2
MTTF
d
(RESPOND)
100 years
→
high
MTTF
d
values for both channels were capped
at 100 years
→
it is not necessary to symme-
trize both channels
Determining
MTTF
d
9 Cabinet Design and EMC
02.12