5-4
B90 Low Impedance Bus Differential System
GE Multilin
5.1 OVERVIEW
5 SETTINGS
5
For voltage elements the primary base quantity is the nominal phase-to-phase primary voltage of the protected system pro-
vided that the VT ratio setting is set to the nominal ratio of the VTs and the secondary voltage setting is set to the phase-to-
phase voltage seen by the relay when the voltage of the protected system in nominal. The UR uses the convention that
nominal voltages in a three-phase system are phase-to-phase voltages.
For example, on a system with a 13.8 kV nominal primary voltage, the base quantity is 13800 V. With 14400:120 V delta-
connected VTs, the secondary base quantity and secondary voltage setting is:
(EQ 5.1)
For wye-connected VTs, the primary and secondary bases quanitities are as before, but the secondary voltage (here a
phase-to-phase ground value) is:
(EQ 5.2)
Many settings are common to most elements and are discussed below:
•
FUNCTION setting:
This setting programs the element to be operational when selected as “Enabled”. The factory
default is “Disabled”. Once programmed to “Enabled”, any element associated with the function becomes active and all
options become available.
•
NAME setting:
This setting is used to uniquely identify the element.
•
PICKUP setting:
For simple elements, this setting is used to program the level of the measured parameter above or
below which the pickup state is established. In more complex elements, a set of settings may be provided to define the
range of the measured parameters which will cause the element to pickup.
•
PICKUP DELAY setting:
This setting sets a time-delay-on-pickup, or on-delay, for the duration between the pickup
and operate output states.
•
RESET DELAY setting:
This setting is used to set a time-delay-on-dropout, or off-delay, for the duration between the
Operate output state and the return to logic 0 after the input transits outside the defined pickup range.
•
BLOCK setting:
The default output operand state of all comparators is a logic 0 or “flag not set”. The comparator
remains in this default state until a logic 1 is asserted at the RUN input, allowing the test to be performed. If the RUN
input changes to logic 0 at any time, the comparator returns to the default state. The RUN input is used to supervise
the comparator. The BLOCK input is used as one of the inputs to RUN control.
•
TARGET setting:
This setting is used to define the operation of an element target message. When set to
“
Disabled
”
,
no target message or illumination of a faceplate LED indicator is issued upon operation of the element. When set to
“Self-Reset”, the target message and LED indication follow the operate state of the element, and self-resets once the
operate element condition clears. When set to “Latched”, the target message and LED indication will remain visible
after the element output returns to logic 0 until a RESET command is received by the relay.
•
EVENTS setting:
This setting is used to control whether the pickup, dropout or operate states are recorded by the
event recorder. When set to “Disabled”, element pickup, dropout or operate are not recorded as events. When set to
“Enabled”, events are created for:
(Element) PKP (pickup)
(Element) DPO (dropout)
(Element) OP (operate)
The DPO event is created when the measure and decide comparator output transits from the pickup state (logic 1) to
the dropout state (logic 0). This could happen when the element is in the operate state if the reset delay time is not 0.
13800
14400
----------------
120
115 V
=
13800
14400
----------------
120
3
----------
66.4 V
=
Summary of Contents for B90
Page 10: ...x B90 Low Impedance Bus Differential System GE Multilin TABLE OF CONTENTS ...
Page 284: ...5 166 B90 Low Impedance Bus Differential System GE Multilin 5 8 TESTING 5 SETTINGS 5 ...
Page 334: ...10 8 B90 Low Impedance Bus Differential System GE Multilin 10 2 BATTERIES 10 MAINTENANCE 10 ...
Page 338: ...A 4 B90 Low Impedance Bus Differential System GE Multilin A 1 PARAMETER LISTS APPENDIX A A ...
Page 460: ...C 30 B90 Low Impedance Bus Differential System GE Multilin C 7 LOGICAL NODES APPENDIX C C ...
Page 476: ...E 10 B90 Low Impedance Bus Differential System GE Multilin E 1 IEC 60870 5 104 APPENDIX E E ...
Page 502: ...viii B90 Low Impedance Bus Differential System GE Multilin INDEX ...