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2.2 GENERAL SETTINGS
The LPS-D counts the total number of breaker operations and calculates and accumulates the total breaker
duty on a per phase basis according to the following equation:
∑
I
Total Duty =
2
where,
I = RMS current
t = breaker operating time
x = user settable exponent
The number of operations and accumulated duty will be compared to set values (entered by user). When the
respective value is reached, an event will be recorded and the non-critical alarm will be initiated if programmed
to do so. The number of operations and the total duty can start from zero, or if the existing number of opera-
tions or total duty is known, those values can be entered into the LPS-D to use as a starting point. The follow-
ing settings (General Settings 400 through 410) need to be made.
401: EXPONENT - Exponent x to use in I
EXPONENT can be set from 1 to 2 in 0.1 steps. Use a value that meets the specific breaker used in the appli-
cation.
402: MAX_OP - Maximum Number Of Breaker Operations Permitted
This number can be set from 0 to 9999. Enter the maximum number of operations that the breaker can tolerate
before maintenance is required.
403: MAX_IXT - Maximum Breaker Duty
This number can be entered in the range of 0 to 999.9M in steps of 0.1K. Enter a number equal to the maxi-
mum duty recommended by the breaker manufacturer. Index Flag 139 Breaker Equipment Duty Alarm
(BRMNDT) is set when the Breaker duty equals 80% of the set value. This flag may be directly assigned to an
output contact, or used in configurable logic.
404: IXTPHASEA - Accumulated Duty, Breaker Phase A
IXTPHASEA can be set over the range of 0 to 999.9M with a step of 0.1K. If the accumulated duty to that point
in time is known, enter that value, otherwise, enter an estimated value or use the default value of zero (0).
405: IXTPHASEB - Accumulated Duty, Breaker Phase B
IXTPHASEB can be set over the range of 0 to 999.9M with a step of 0.1K. If the accumulated duty to that point
in time is known, enter that value, otherwise, enter an estimated value or use the default value of zero (0).
406: IXTPHASEC - Accumulated Duty, Breaker Phase C
IXTPHASEC can be set over the range of 0 to 999.9M with a step of 0.1K. If the accumulated duty to that point
in time is known, enter that value, otherwise, enter an estimated value or use the default value of zero (0).
407: NUM_OP - Present Number Of Breaker Operations
(Three Phase Tripping models only)
NUM_OP can be set over the range of 0 to 9999 with a step of 1. If the number of operations to that point in
time is know, enter that value, otherwise, enter an estimated value or use the default value of zero (0). Index
Flag 138: Number of Breaker Operations Alarm (BRMNOP) is set when the Breaker duty equals the set value.
This flag may be directly assigned to an output contact, or used in configurable logic.
2-
8
x
t
x
t Calculation
LPS-D Line Protection System
2 CALCULATION OF SETTINGS
2.2.4 EQUIPMENT DUTY
GE Power Management
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