Figure 2.1 Current And Voltage Input - Siemens 7SN71 Instruction Manual

2
Method of operation
Transient earth-fault relay 7SN71
2B1
I = 1 A
N
2B2
1B2
I = 5 A
N
1B1
I
E
2A1
V
L1
2A2
V
L2
2A3
V
L3
2A4
V
E
1A4
PE
Figure 2.1 Current and voltage input
2 - 2
Instruction Manual Order No.: E50410-A0007-U501-A1-7691
S
I>
R
S
I>
R
&
V>
&
V>
V>
0...70 ms
3
=1
S
R
t
v
M
S
R
2...0 s
4
Reset
I +
1
I -
V -
2
V +
"Release"
Continous
earth fault
Siemens AG March 1997