GE G30 Instruction Manual page 456

GROUPED ELEMENTS
5
The split phase element principle of operation is as follows. First, define the following parameters:
I = split-phase current
split
I = load current
load
pickup = pickup setting
min_load = minimum load supervision setting
Then, the expected value of the steady state unbalance (defined as bias current) is expressed as follows:
where
and offset is the split phase current at no-load. In "Over" mode, the element picks up if
5-242
Figure 5-125: Split phase protection for two CTs
Figure 5-126: Split phase protection for one CT
I = slope x I + offset
bias load
(I - I > pickup) and (I
split bias load
≥ min_load)
G30 GENERATOR PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETTINGS
Eq. 5-49
Eq. 5-50
Eq. 5-51