3-12
T60 Transformer Protection System
GE Multilin
3.2 WIRING
3 HARDWARE
3
Figure 3–13: CONTROL POWER CONNECTION
3.2.4 CT/VT MODULES
A CT/VT module can have voltage or current inputs on channels 1 through 4 inclusive, or channels 5 through 8 inclusive.
Channels 1 and 5 are intended for connection to phase A, and are labeled as such in the relay. Likewise, channels 2 and 6
are intended for connection to phase B, and channels 3 and 7 are intended for connection to phase C.
Channels 4 and 8 are intended for connection to a single-phase source. For voltage inputs, these channel are labelled as
auxiliary voltage (VX). For current inputs, these channels are intended for connection to a CT between system neutral and
ground, and are labelled as ground current (IG).
Verify that the connection made to the relay terminals for nominal current of 1 A or 5 A matches the
secondary rating of the connected CTs. Unmatched CTs can result in equipment damage or inade-
quate protection.
To connect the module, size 12 American Wire Gauge (AWG) is commonly used; the maximum size is 10 AWG.
CT/VT modules may be ordered with a standard ground current input that is the same as the phase current input. Each AC
current input has an isolating transformer and an automatic shorting mechanism that shorts the input when the module is
withdrawn from the chassis. There are no internal ground connections on the current inputs. Current transformers with 1 to
50000 A primaries and 1 A or 5 A secondaries can be used.
CT/VT modules with a sensitive ground input are also available. The ground CT input of the sensitive ground modules is 10
times more sensitive than the ground CT input of standard CT/VT modules. However, the phase CT inputs and phase VT
inputs are the same as those of regular CT/VT modules.
The above modules have enhanced diagnostics, when ordered as such, that can automatically detect CT/VT hardware fail-
ure and take the relay out of service.
CT connections for both ABC and ACB phase rotations are identical as shown in the
Typical wiring diagram
.
The exact placement of a zero-sequence core balance CT to detect ground fault current is shown as follows. Twisted-pair
cabling on the zero-sequence CT is recommended.
AC or DC
NOTE:
14 gauge stranded
wire with suitable
disconnect devices
is recommended.
Heavy copper conductor
or braided wire
Switchgear
ground bus
UR-series
protection system
FILTER SURGE
–
+
LOW
+
HIGH
B8b B8a B6a B6b B5b
CONTROL
POWER
827759AA.CDR
—
+
OPTIONAL
ETHERNET SWITCH
AC or DC
GND
NOTICE
Summary of Contents for UR T60
Page 10: ...x T60 Transformer Protection System GE Multilin TABLE OF CONTENTS ...
Page 14: ...xiv T60 Transformer Protection System GE Multilin 0 1 BATTERY DISPOSAL 0 BATTERY DISPOSAL 0 ...
Page 34: ...1 20 T60 Transformer Protection System GE Multilin 1 5 USING THE RELAY 1 GETTING STARTED 1 ...
Page 436: ...5 298 T60 Transformer Protection System GE Multilin 5 10 TESTING 5 SETTINGS 5 ...
Page 678: ...C 30 T60 Transformer Protection System GE Multilin C 7 LOGICAL NODES APPENDIX C C ...
Page 688: ...D 10 T60 Transformer Protection System GE Multilin D 1 IEC 60870 5 104 PROTOCOL APPENDIX D D ...
Page 700: ...E 12 T60 Transformer Protection System GE Multilin E 2 DNP POINT LISTS APPENDIX E E ...
