Operating instructions7SV512
V1
C53000---G1176---C91
74
With address 1112, the device is instructed as to
howthe earth current inputoftherelay isconnected.
This information is important for the monitoring of
measured values.
Two possibilities exist for the earth current path:
--- Connection ofthe earth current fromthe starpoint
of the current transformers (standard circuit ar-
rangement, see also Appendix B, Figure B.2):
Address 1112 is then set as Ie/Iph = 1.00
--- Connection of the earth current from a separate
earth current detection transformer (e.g. summa-
tion current transformer, see also Appendix B,
Figure B.4).
Address 1112 is then set as
ratio of the earth current CT
ratio of the phase current CT
Ie/Iph =
Example:
Phase current transformers 400A/5A
Summation transformer 60A/1A
60/1
400/5
= 0.75Ie/Iph =
Under address 1115, the minimum trip command
duration canbeset. This time is then valid for all pro-
tection functions of the device which can issue a trip
signal.
1 1 1 2 I e / I p h
1 . 0 0
Matching factor for earth current:
1.00 for connection in c.t. starpoint;
summation (earth) c.t. ratio
(phase) c.t. ratio
for connection to separate earth current trans-
former
Smallest setting value: 0.10
Largest setting value: 20.00
1 1 1 5 T - T R I P
0 . 1 0 s
Minimum duration of trip command
Smallest setting value: 0.00 s
Largest setting value: 32.00 s
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