Installation and Commissioning
8-12
7SA6 Manual
C53000-G1176-C156-2
This results in an upper limit for the resistance dimension, R
max
, and a lower limit R
min
,
from which the optimal value of the arithmetic mean should be selected.
To ensure the minimum voltage for the control of the binary input, R
max
is derived as:
So the circuit breaker trip coil does not remain energized in the above case, R
min
is
derived as:
If the calculation results that R
max
< R
min
, then the calculation must be repeated, with
the next lowest switching threshold U
BI min
, and this threshold must be implemented
in the relay using plug-in bridges (see Sub-section 8.1.3).
For the power consumption of the resistance:
Example:
I
BI (HIGH)
Constant current with BI on (= 1,7 mA)
U
BI min
Minimum control voltage for BI
=19 V for delivery setting for nominal voltage of 24/48/60 V;
=73 V for delivery setting for nominal voltage of 110/125/220/250 V;
UCTR
Control voltage for trip circuit
R
CBTC
DC resistance of circuit breaker trip coil
U
CBTC (LOW)
Maximum voltage on the circuit breaker trip coil that does not lead to tripping
I
BI (HIGH)
1.8 mA (from SIPROTEC
®
7SA6)
U
BI min
19 V for delivery setting for nominal voltage 24/48/60 V
73 V or delivery setting for nominal voltage 110/125/220/250 V
UCTR
110 V (from system / release circuit)
R
CBTC
500
Ω
(from system / release circuit)
U
CBTC (LOW)
2 V (from system / release circuit)
R
R
max
R
min
+
2
---------------------------------
=
R
max
U
CRT
U
BI min
–
I
BI (High)
--------------------------------------
è
ø
æ
ö
R
CBTC
–
=
R
min
R
TC
U
CTR
U
TC (LOW)
–
U
TC (LOW)
-----------------------------------------------
è
ø
æ
ö
⋅
=
P
R
I
2
R
⋅
U
C TR
R
R
CBTC
+
----------------------------
è
ø
æ
ö
2
R
⋅
=
=
R
max
110 V - 19 V
1.8 m
Α
---------------------------------
è
ø
æ
ö
500
Ω
–
=
R
min
500Ω
110 V - 2 V
2V
------------------------------
è
ø
æ
ö
⋅
=
R
max
50.1 k
Ω
=
R
min
27 k
Ω
=
R
R
max
R
min
+
2
--------------------------------
38.6 k
Ω
=
=
Summary of Contents for siprotec 7SA6
Page 2: ...Siemens Aktiengesellschaft Book No C53000 G1176 C156 2 ...
Page 18: ...xviii 7SA6 Manual C53000 G1176 C156 2 ...
Page 32: ...Introduction 1 14 7SA6 Manual C53000 G1176 C156 2 ...
Page 82: ...Hardware and Connections 2 50 7SA6 Manual C53000 G1176 C156 2 ...
Page 119: ...SIPROTEC 4 Devices 4 25 7SA6 Manual C53000 G1176 C156 2 Figure 4 20 CFC Logic example ...
Page 190: ...Configuration 5 62 7SA6 Manual C53000 G1176 C156 2 ...
Page 652: ...Installation and Commissioning 8 78 7SA6 Manual C53000 G1176 C156 2 ...
Page 724: ...Technical Data 10 56 7SA6 Manual C53000 G1176 C156 ...
Page 800: ...Appendix A 76 7SA6 Manual C53000 G1176 C156 2 ...
Page 866: ...Appendix B 66 7SA6 Manual C53000 G1176 C156 2 ...