Other Features; Flash Memory; Line Overload; Current Unbalance Detection - GE LPS-D Instruction Manual

1.5 OTHER FEATURES

1 PRODUCT DESCRIPTION
1.5 OTHER FEATURES

1.5.1 FLASH MEMORY

1
The program code resides in Flash memory rather than EPROM. This new technology provides the same func-
tionality during normal operations of the relay. The advantage to the Flash Memory is it can be changed for
software upgrades without opening the relay. The contents can be overwritten through the communications
ports already provided in the relay. The ability to change the contents requires special software and does not
come with any of the standard LPS-D communications packages.

1.5.2 LINE OVERLOAD

The Line Overload function provides an event and a programmable signal. This signal can be used to provide
alarm indication (contact closure) that the load current on the protected line has exceeded a set level for a set
time interval. Two alarm levels are included. Level 1 is generally set with a lower pickup setting and a longer
time delay than level 2.

1.5.3 CURRENT UNBALANCE DETECTION

If the Fault Detector, FD, remains pickup up for 60 seconds, a non-critical alarm is issued and an event mes-
sage generated. This function indicates sustained unbalanced current conditions such as an open or shorted
current transformer.

1.5.4 FAULT LOCATION

A separate algorithm provides fault-location information, which is presented as miles, kilometers, or percent of
line from the relay location to the fault. The distance to the fault is based on a line length provided by the user
as a setting. Fault location output is displayed on the front panel liquid crystal display as part of the target infor-
mation following a relay trip, and it is also contained in the Fault Report described below.

1.5.5 FAULT REPORT

When a fault or oscillography trigger occurs, pertinent information, consisting of unit ID, date and time, operat-
ing time, prefault currents, fault currents and voltages, fault type, trip type, distance to fault, and selected
events, is stored in memory. The number of fault events that are stored is selectable by the user and may be
set for: 6, 12, 24, or 36 fault reports. Each fault report is associated with an oscillography data file. See Section
8.2.3: REQUEST FAULT INFORMATION on page 8–20 for obtaining a fault report via the local user interface
and Section 11.8: INFORMATION on page 11–18 for fault reports using ALPS-Link.

1.5.6 OSCILLOGRAPHY

Oscillography data are stored in memory each time the LPS-D issues a trip and, optionally when an internal
oscillography trigger flag is set or an external contact is closed. Protection Setting 2026: CONFOSC allows a
configurable oscillography trigger to be assigned by Xpression Builder.
Note that OSC Trigger stores oscillography data, but does not necessarily set t = 0, the time sample that delin-
eates between prefault and postfault oscillography cycles. The term disturbance period is defined as the num-
ber of cycles of oscillography data (prefault plus postfault) as determined by General Setting 301: NUMFLTS. If
the internal Fault Detector, FD, comes up initially and OSC Trigger follows within the disturbance period, oscil-
lography data are stored whether or not the LPS-D issues a trip.
If the LPS-D issues a trip, then a normal fault report is stored as part of the oscillography data. If the LPS-D
does not issue a trip, a pseudofault report is created. The trip type is listed as OSC, the trip time is set to when
the OSC Trigger occurred, the operating time is set to zero, and the fault type and location are computed,
1- LPS-D Line Protection System GE Power Management
18