GE Multilin L30 Line Current Differential System 9-13
9 APPLICATION OF SETTINGS 9.4 INSTANTANEOUS ELEMENTS
9
The elements must be treated selectively. If, for example, the phase over or under voltage setting includes margin or time
delay sufficient to accommodate the maximum additional error on re-synchronization, blocking or delay are not needed for
these elements. Similarly, if the phase instantaneous overcurrent setting has sufficient margin, blocking is not needed. Note
that significant zero-sequence and negative-sequence current or voltage error do not appear during L30 startup, therefore
all sequence-based elements using these quantities are safe.
For the three-terminal line, the synchronization process is longer and block times need to be three times longer than two-
terminal line block times.