Connecting To Ct And Vt Circuits - ABB Relion 670 Series Installation Manual

Section 6
Connecting
The auxiliary power wiring should have a minimum cross-sectional area of 1.0 mm
rating of 250 V. Branch circuit protection must be provided in the auxiliary power supply wiring to
the IED, and if necessary it must be possible to disconnect manually from the power supply. Fuse
or circuit breaker up to 6 A and 250 V should be close to the equipment. It is recommended to
separate the instrument transformer leads from the other cables, that is, they should not be run in
the same cable ducts or loom. The connections are made on connector X11.
6.1.4

Connecting to CT and VT circuits

CTs and VTs are connected to the 24–pole connector of the Transformer input module (TRM) on
the rear side of the IED. Connection diagram for TRM is shown in figure 16.
Use a solid conductor with a cross section area between 2.5-6 mm
conductor with a cross section area between 2.5-4 mm
If the IED is equipped with a test-switch of type RTXP 24, COMBIFLEX wires with 20 A sockets
must be used to connect the CT and VT circuits.
Connectors on TRM (for location see section
transformer circuits are so called "feed-through IED blocks" and are designed for conductors with
cross sectional area up to 4 mm
tightened with a torque of 1Nm.
Connector terminals for CT and VT circuits, as well as terminals for binary input and output
signals, can be of either ringlug or compression connection type, depending on ANSI/IEC
standards, or customers choice.
48
Insert only the corresponding male connector to the female connector. Inserting
anything else (such as a measurement probe) may violate the female connector
and prevent a proper electrical contact between the printed circuit board and the
external wiring connected to the screw terminal block.
2
(AWG 12). The screws used to fasten the conductors should be
2
(AWG14-10) or a stranded
2
(AWG14-12).
"Rear side connectors") for current and voltage
1MRK 514 026-UUS F
2
and a voltage
M11991-6 v3
M11991-10 v4
670 series
Installation manual