GE b30, Instruction Manual, Page: 353 / 632

CHAPTER 5: SETTINGS SYSTEM SETUP
B30 BUS DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL 5-145
5
The phase reference and frequency tracking AC signals are selected based upon the source configuration, regardless of
whether or not a particular signal is actually applied to the relay.
Phase angle of the reference signal always displays zero degrees and all other phase angles are relative to this signal. If the
pre-selected reference signal is not measurable at a given time, the phase angles are not referenced.
The phase angle referencing is done via a phase locked loop, which can synchronize independent UR-series relays if they
have the same AC signal reference. This results in very precise correlation of phase angle indications between different UR-
series relays.
FREQUENCY TRACKING
is set to “Disabled” only in unusual circumstances; consult GE Grid Solutions for special variable-
frequency applications.
5.5.3 Signal sources
SETTINGS  SYSTEM SETUP  SIGNAL SOURCES  SOURCE 1(6)
Identical menus are available for each source. The "SRC 1" text can be replaced by with a user-defined name appropriate
for the associated source.
The first letter in the source identifier represents the module slot position. The number directly following this letter
represents either the first bank of four channels (1, 2, 3, 4) called “1” or the second bank of four channels (5, 6, 7, 8) called
“5” in a particular CT/VT module. See the Introduction to AC Sources section at the beginning of this chapter for details.
It is possible to select the sum of all CT combinations. The first channel displayed is the CT to which all others are referred.
For example, the selection “F1+F5” indicates the sum of each phase from channels “F1” and “F5,” scaled to whichever CT
has the higher ratio. Selecting “None” hides the associated actual values.
The approach used to configure the AC sources consists of several steps; first step is to specify the information about each
CT and VT input. For CT inputs, this is the nominal primary and secondary current. For VTs, this is the connection type, ratio
and nominal secondary voltage. Once the inputs have been specified, the configuration for each source is entered,
including specifying which CTs are summed together.
5.5.3.1 User selection of AC parameters for comparator elements
CT/VT modules automatically calculate all current and voltage parameters from the available inputs. Users must select the
specific input parameters to be measured by every element in the relevant settings menu. The internal design of the
element specifies which type of parameter to use and provides a setting for source selection. In elements where the
parameter can be either fundamental or RMS magnitude, such as phase time overcurrent, two settings are provided. One
setting specifies the source, the second setting selects between fundamental phasor and RMS.
The frequency tracking feature functions only when the B30 is in the “Programmed” mode. If the B30 is “Not
Programmed,” then metering values are available but can exhibit significant errors.
 SOURCE 1


SOURCE 1 NAME:
SRC 1
Range: up to 20 alphanumeric characters

SOURCE 1 PHASE CT:
None
Range: None, F1,... up to any 6 CTs. Only Phase CT
inputs are displayed.

SOURCE 1 GROUND CT:
None
Range: None, F1,... up to any 6 CTs. Only Ground CT
inputs are displayed.

SOURCE 1 PHASE VT:
None
Range: None, S5
Only phase voltage inputs are displayed

SOURCE 1 AUX VT:
None
Range: None, S5
Only auxiliary voltage inputs are displayed