Siemens SIPROTEC 7SD610 User Manual

Functions
2.1 General
SIPROTEC, 7SD610, Manual
C53000-G1176-C145-6, Release date 02.2011
35
Voltage Connection
The device features four voltage measuring inputs, three of which are connected to the set of voltage trans-
formers. Various possibilities exist for the fourth voltage input U
4
:
• Connection of the U
4
input to the open delta winding Ue–n of the voltage transformer set:
Address 210 is then set to: U4 transformer = Udelta transf..
When connected to the e-n winding of a set of voltage transformers, the voltage transformation ratio of the
voltage transformers is usually:
The factor Uph/Udelta (secondary voltage, address 211 Uph / Udelta) must be set to 3/√3
= √3 ≈ 1.73.
For other transformation ratios, i.e. the formation of the displacement voltage via an interconnected trans-
former set, the factor must be corrected accordingly. This factor is of importance for the monitoring of the
measured values and the scaling of the measurement and disturbance recording signals.
• If the input U
4
is not required, set:
Address 210 U4 transformer = Not connected.
Factor Uph / Udelta (address 211, see above) is also of importance in this case, as it is used for scaling
the measured data and fault recording data.
Connection of the Currents
The device features four current measurement inputs, three of which are connected to the set of current trans-
formers. Various possibilities exist for the fourth current input I
4
:
• Connection of the I
4
input to the earth current in the starpoint of the set of current transformers on the pro-
tected feeder (normal connection):
Address 220 is then set to: I4 transformer = In prot. line and address 221 I4/Iph CT = 1.
• Connection of the I
4
input to a separate earth current transformer on the protected feeder (e.g. a summation
CT or core balance CT):
Address 220 is then set to: I4 transformer = In prot. line and address 221 I4/Iph CT is set:
Example
:
Phase current transformers 500 A / 5 A
Earth current transformer 60 A / 1 A
• Connecting the I
4
input to the starpoint current of a transformator; this is used for the earth fault differential
protection:
Address 220 is then set to: I4 transformer = IY starpoint, and address 221 I4/Iph CT is accord-
ing to transformation ratio of the starpoint transformer to the transformer set of the protected line.
• If the input I
4
is not required, set:
Address 220 I4 transformer = Not connected,
Address 221 I4/Iph CT is then irrelevant.
In this case, the neutral current is calculated from the sum of the phase currents.

Siemens SIPROTEC 7SD610 Specifications

General

Brand	Siemens
Model	SIPROTEC 7SD610
Category	Relays
Language	English