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2 CALCULATION OF SETTINGS
2.2 GENERAL SETTINGS
2.2 GENERAL SETTINGS
2.2.1 CONFIGURATION
101: UNITID - Unit ID Number
The UNITID is a decimal number between 0 and 9999 that uniquely identifies an LPS-D relay. When the LPS-
D is accessed via one of the serial ports the UNITID must be known to establish communication, thus providing
an additional measure of security. UNITID can only be changed via the keypad. It is not possible to change
UNITID with the ALPS-Link communications program.
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102: SYSFREQ - System Frequency
SYSFREQ establishes the operating frequency of the LPS-D. It can be set to either 50 Hz or 60 Hz. When this
setting is changed it will only be implemented by turning the DC power off and then on to re-initialize the relay.
103: PHASRROTATE - Phase Rotation
PHASRROTATE can be set to ABC or ACB to match the positive-sequence phase rotation for the power sys-
tem where the LPS-D is installed. This setting permits proper reporting the faulted phase or phase pair.
104: TIMESYNCH - Select Time Synchronization
TIMESYNCH determines the method of synchronizing the LPS-D internal clock; it can be set to 0 (INTERNAL)
or 1 (IRIG-B). TIMESYNCH = 0 lets the clock run freely from the internal oscillator. TIMESYNCH = 1 synchro-
nizes the clock using an IRIG-B signal connected directly to the LPS-D via the assigned port.
105: NUM_BKR - Number of Breakers
NUM_BKR can be set to either 1 or 2. When set to 1, the TRIP and CLOSE commands can only be used to
activate the BREAKER 1 trip and close outputs. When set to 2, the TRIP and CLOSE commands can selec-
tively be used to activate either the BREAKER 1 or BREAKER 2 outputs. When a POTT or PUTT scheme is
selected, this setting also determines whether 52/b contacts from one breaker or two breakers are used to key
the transmitter with the breaker(s) open.
106: NUM_TC - Number of Trip Circuits
The LPS-D has 6 high-speed (SCR or relay contact) trip outputs available, labeled T1 to T6. Assignment of trip
outputs is made via the NUM_TC setting and is directly coupled to General Setting 105: NUM_BKR.
With the Single Phase Tripping model, all six outputs (T1 to T6) are available and are assigned per the
NUM_TC setting as shown below in Table 2–1: NUM_TC SETTING (SINGLE PHASE MODELS). In this case,
outputs T4 to T6 are available for assignment through Xpression Builder only when one breaker with one set of
trip coils is being controlled (NUM_TC = 1).
With the Three Phase Tripping model, four of the six outputs (T1 to T4) are available for tripping and are
assigned per the NUM_TC setting as shown below in Table 2–2: NUM_TC SETTING (THREE PHASE MOD-
ELS). If one breaker with a single trip circuit is being used (NUM_TC = 1), then outputs T2 to T6 are available
for assignment to different tasks through the Xpression Builder program provided with the LPS-D. Outputs T3
and T4 are used only if two breakers are being controlled and if each of the breakers has two independent trip
circuits (NUM_TC = 2). If independent trip coils are not being used, then the T3 to T6 contacts can be re-
assigned through Xpression Builder.
The LPS-D has the capability (when enabled) to trip the breaker(s) locally through the keypad, or remotely via
the ALPS-Link program or ASCII commands. For the LPS-D to recognize which breaker should be tripped, the
NUM_TC setting must be set as shown in the tables below and the trip outputs connected to the appropriate
trip coils assigned in the tables. For example, if a three phase tripping scheme is employed and NUM_TC = 2,
then trip output T1 must be connected to the trip coil TC-1 of breaker number 1 and the output T2 must be con-
nected to the trip coil TC-1 of breaker number 2.
GE Power Management
LPS-D Line Protection System
2-
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