CHAPTER 5: SETTINGS
GROUPED ELEMENTS
N60 NETWORK STABILITY AND SYNCHROPHASOR MEASUREMENT SYSTEM – INSTRUCTION MANUAL
5-233
5
Figure 5-122: Phase directional logic
5.7.5 Neutral current
5.7.5.1 Menu
SETTINGS
GROUPED ELEMENTS
SETTING GROUP 1(6)
NEUTRAL CURRENT
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.
NEUTRAL CURRENT
NEUTRAL TOC 1
See below
NEUTRAL TOC 6
NEUTRAL IOC 1
NEUTRAL IOC 12