GE G30 Instruction Manual page 396

GROUPED ELEMENTS
SPLIT PHASE SOURCE
protection.
SPLIT PHASE LOAD SOURCE
SPLIT PHASE A(C) PICKUP
phase) current due to an inter-turn fault.
SPLIT PHASE A(C) OFFSET
split phase current during normal (unfaulted) operation. Assign the split phase current and the load current (positive
sequence) to the data logger to identify the optimum value for this setting.
SPLIT PHASE A(C) SLOPE
pickup of the element due to variations in generator loading. The slope is defined as the ratio of the per-unit split phase
current over the per-unit load current. Assign the split phase current and the load current (positive sequence) to the data
logger to identify the optimum value for this setting.
SPLIT PHASE MIN LOAD
SPLIT PHASE MODE
phase current rises above the biased offset current plus the pickup setting. If "Over-under" mode is chosen, the element
also picks up if the split phase current falls below the biased offset current minus the pickup setting. See the earlier
description for details.
SPLIT PHASE DELAY
disturbance the CTs can saturate. CT saturation can cause a spurious split phase current, especially in the case where the
split phase current is derived from the external summation of two split phase CTs (first figure presented). In this instance, a
time delay can be used to ride through the saturation event. Alternately, the CT saturation flag also can be used to
supervise the function.
5
5-222
—Specifies a signal source used to provide current from the split phase CT to the split phase
— Specifies a signal source used to provide current from the load CT to the split phase protection.
— Specifies a pickup level for each phase. Set it less than the minimum expected unbalance (split
— Specifies the steady-state split phase current at no-load for the each phase. Set it equal to the
— Specifies the slope of split phase characteristic for each phase. This setting is used to bias the
— Specifies the minimum load (positive-sequence current) supervision level.
— Specifies the mode of operation. If the "Over" mode is chosen, the element picks up when the split
— Specifies a time delay required to operate after the pickup condition is established. During an external
G30 GENERATOR PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETTINGS