3-20
B90 Low Impedance Bus Differential System
GE Multilin
3.2 WIRING
3 HARDWARE
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 3–18: DRY AND WET CONTACT INPUT CONNECTIONS
Wherever a tilde “~” symbol appears, substitute with the slot position of the module.
Contact outputs can be ordered as form-A or form-C. The form-A contacts can be connected for external circuit supervi-
sion. These contacts are provided with voltage and current monitoring circuits used to detect the loss of DC voltage in the
circuit, and the presence of DC current flowing through the contacts when the form-A contact closes. If enabled, the current
monitoring can be used as a seal-in signal to ensure that the form-A contact does not attempt to break the energized induc-
tive coil circuit and weld the output contacts.
There is no provision in the relay to detect a DC ground fault on 48 V DC control power external output. We recom-
mend using an external DC supply.
NOTE
NOTE
Summary of Contents for B90 UR Series
Page 316: ...A 4 B90 Low Impedance Bus Differential System GE Multilin A 1 PARAMETER LISTS APPENDIX A A ...
Page 406: ...B 90 B90 Low Impedance Bus Differential System GE Multilin B 4 MEMORY MAPPING APPENDIX B B ...
Page 436: ...C 30 B90 Low Impedance Bus Differential System GE Multilin C 7 LOGICAL NODES APPENDIX C C ...
Page 446: ...D 10 B90 Low Impedance Bus Differential System GE Multilin D 1 IEC 60870 5 104 APPENDIX D D ...
