Conventions - GE 750 Instruction Manual

750/760
Feeder Management Relay

Conventions

Test Equipment
7–2
The setpoints considered for the measurement of parameters and the operation of
features are shown on the logic diagrams. All settings must be set to the application
requirement by the user before beginning the tests. To facilitate testing it is
recommended that all functions be initially set to "Disabled". Every feature which
will be used in the application should be set to the required function for the test,
then returned to "Disabled" at completion. Each feature can then be testing without
complications caused by operations of other features. At the completion of all tests
each feature is then set as required.
The procedures for testing of common operations will not be repeated in every test.
The common features, and the test procedure location are as follows:
• Thermal Exponential Demand Characteristic: Measurement of Current Demand
• Block Interval Demand Characteristic: Measurement of Current Demand
• Rolling Interval Demand Characteristic: Measurement of Current Demand
• Feature Function as "Trip", "Alarm", or "Control": Phase Time Overcurrent 1
• Fixed Delay Timing: Phase Time Overcurrent 1
• Front Panel RESET Key Resetting: Phase Time Overcurrent 1
• Logic Input Resetting: Phase Time Overcurrent 1
• Feature Blocking from Logic Inputs: Phase Time Overcurrent 1
• Element Operation of Output Relays: Phase Time Overcurrent 1
• Number Of Faulted Phases: Phase Instantaneous Overcurrent 1
• Feature Function as "Trip + AR": Autoreclose (760 Only)
We also recommend that the procedures outlined in Placing the Relay In Service on
page 7–63 be performed for all installations to verify proper operation and function
of the equipment.
The following conventions are used for the remainder of this chapter:
• It is assumed the VT and CT inputs are wired in accordance with the Typical
Wiring Diagram on page 3–7. With these connections, and assumed where
phase angles are noted, a unity power factor current in the primary circuit flows
into the relay marked terminal, with no phase shift with respect to the
corresponding phase-neutral voltage.
• The phase rotation of the relay test set is ABC.
• A current that lags a voltage has a positive phase angle.
• Phase A to neutral voltage is indicated by V
• Phase A to B voltage is indicated by V
• The sign convention for power parameters is as shown in FIGURE 6–3: Power
Quantity Relationships on page 6–8.
• The actual value display at the beginning of some sections is the display for the
measured parameter. All actual values are mentioned with their "path" as a
means of specifying the relative location of a particular message with regards to
its parent messages. For instance, the analog input, which in the message
structure is located under actual values page
under subheading
ANALOG INPUT
.
INPUT ANALOG INPUT
Excluding data acquisition testing, tests may be performed using the simulation
feature, eliminating the need of external AC voltage and current inputs. System
parameters, such as current and voltage information, are entered as setpoints.
When placed in simulation mode, the relay suspends reading actual AC inputs and
uses the programmed phasors to generate sample values that are placed in the
Trace Memory. All metering calculations and logic associated with protection,
monitoring, and control, are performed normally, using phasors calculated from the
samples placed in the memory instead of phasors generated from the input
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(arrowhead on the "a").
an
(arrowhead on the "a").
ab
as the first message
A2 METERING
, would be written as:
A2 METERING
Overview
ANALOG
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