Neutral Current - GE G30 Instruction Manual

GROUPED ELEMENTS
The phase directional element responds to the forward load current. In the case of a following reverse fault, the
element needs some time—in the order of 8 ms—to establish a blocking signal. Some protection elements, such as
instantaneous overcurrent, respond to reverse faults before the blocking signal is established. Therefore, a
coordination time of at least 10 ms must be added to all the instantaneous protection elements under the
supervision of the phase directional element. If current reversal is of concern, a longer delay—in the order of 20
ms—is needed.
5

5.7.5 Neutral current

5.7.5.1 Menu
SETTINGS  GROUPED ELEMENTS  SETTING GROUP 1(6)  NEUTRAL CURRENT
 NEUTRAL CURRENT

5-198
Figure 5-99: Phase directional logic
 NEUTRAL TOC 1


 NEUTRAL TOC 2


 NEUTRAL IOC 1


 NEUTRAL

 DIRECTIONAL OC1
 NEUTRAL

 DIRECTIONAL OC2
See below
See page 5-200
See page 5-201
G30 GENERATOR PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETTINGS