GE Multilin
T60 Transformer Protection System
3-19
3 HARDWARE
3.2 WIRING
3
CONTACT INPUTS
A dry contact has one side connected to terminal B3b. This is the positive 48 V DC voltage rail supplied by the power sup-
ply module. The other side of the dry contact is connected to the required contact input terminal. Each contact input group
has its own common (negative) terminal which must be connected to the DC negative terminal (B3a) of the power supply
module. When a dry contact closes, a current of 1 to 3 mA flows through the associated circuit.
A wet contact has one side connected to the positive terminal of an external DC power supply. The other side of this contact
is connected to the required contact input terminal. If a wet contact is used, then the negative side of the external source
must be connected to the relay common (negative) terminal of each contact group. The maximum external source voltage
for this arrangement is 300 V DC.
The voltage threshold at which each group of four contact inputs detects a closed contact input is programmable as
17 V DC for 24 V sources, 33 V DC for 48 V sources, 84 V DC for 110 to 125 V sources, and 166 V DC for 250 V sources.
Figure 3–17: DRY AND WET CONTACT INPUT CONNECTIONS
Wherever a tilde “~” symbol appears, substitute with the slot position of the module.
There is no provision in the relay to detect a DC ground fault on 48 V DC control power external output. We recommend
using an external DC supply.
GENERAL APPLICATION CONSIDERATIONS
Contacts outputs of protective relays, auxiliary contacts from breakers, disconnectors and other devices, are generally con-
nected to contacts inputs of protective relays. In some situations, the contact outputs of some protective relays can have
high impedance connected across it. When such a contact output is connected across a T60 contact input, it can spuriously
operate the T60 input even when the output is open, if there is a substantial distributed capacitance (represented by C1)
present in the wiring between the output and the T60 input and the debounce time setting in the T60 relay is low enough.
This false assertion of the contact input, when there is inadvertent ground present at the DC positive terminal, can be pre-
vented by inserting a resistor across the T60 input.
The following figure shows a typical DC circuit, with battery ground detection, of contact input. The contact output has par-
allel impedance across it (represented by R1).
827741A5.CDR
24 to 250 V
(Wet)
(Dry)
Contact input 1
Contact input 2
Contact input 3
Surge
Contact input 4
~7a
Common
~7b
~7c
~8a
~8b
~8c
Contact input 1
Contact input 2
Contact input 3
Surge
Contact input 4
~7a
Common
~7b
~7c
~8a
~8b
~8c
Control power
Surge
B5b
Filter
B8b
B6b
B6a
B8a
Critical failure
B1b
48 V DC output
B3b
B1a
B2b
B3a
HI+
LO+
Power supply module
Terminals from type 6B
contact input/output module
Terminals from type 6B
contact input/output module
NOTE
Summary of Contents for T60
Page 6: ...vi T60 Transformer Protection System GE Multilin TABLE OF CONTENTS ...
Page 14: ...xiv T60 Transformer Protection System GE Multilin TABLE OF CONTENTS ...
Page 34: ...1 20 T60 Transformer Protection System GE Multilin 1 5 USING THE RELAY 1 GETTING STARTED 1 ...
Page 490: ...5 344 T60 Transformer Protection System GE Multilin 5 10 TESTING 5 SETTINGS 5 ...
Page 522: ...6 32 T60 Transformer Protection System GE Multilin 6 5 PRODUCT INFORMATION 6 ACTUAL VALUES 6 ...
Page 536: ...7 14 T60 Transformer Protection System GE Multilin 7 1 COMMANDS 7 COMMANDS AND TARGETS 7 ...
Page 568: ...10 12 T60 Transformer Protection System GE Multilin 10 6 DISPOSAL 10 MAINTENANCE 10 ...
Page 596: ...A 28 T60 Transformer Protection System GE Multilin A 1 PARAMETER LISTS APPENDIX A A ...
Page 716: ...B 120 T60 Transformer Protection System GE Multilin B 4 MEMORY MAPPING APPENDIX B B ...
Page 762: ...E 10 T60 Transformer Protection System GE Multilin E 1 IEC 60870 5 104 PROTOCOL APPENDIX E E ...
Page 774: ...F 12 T60 Transformer Protection System GE Multilin F 2 DNP POINT LISTS APPENDIX F F ...