GE L30 Instruction Manual page 291

5 SETTINGS
usually not critical. This delay will provide security against spurious neutral current during switch-off transients and
external fault clearing.
• CURRENT DIFF DTT: This setting enables and disables the sending of a DTT by the current differential element on
per single-phase basis to remote devices. To allow the L30 to restart from master-master to master-slave mode (very
important on three-terminal applications),
• CURRENT DIFF KEY DTT: This setting selects an additional protection element (besides the current differential ele-
ment; for example, distance element or breaker failure) which keys the DTT on a per three-phase basis.
For the current differential element to function properly, it is imperative that all L30 devices on the protected line
have exactly identical firmware revisions. For example, revision 5.62 in only compatible with 5.62, not 5.61 or 5.63.
NOTE
GE Multilin
must be set to "Enabled".
CURR DIFF DTT
L30 Line Current Differential System
5.6 GROUPED ELEMENTS
5-155
5