GE L90

CHAPTER 5: SETTINGS GROUPED ELEMENTS
L90 LINE CURRENT DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL 5-267
5
PHASE DIR 1 EVENTS — This setting enables and disables the logging of phase directional overcurrent events in the
sequence of events recorder.
Figure 5-145: Phase directional logic
5.7.9 Neutral current
5.7.9.1 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
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 NEUTRAL TOC 1
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See below
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 NEUTRAL TOC 6
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 NEUTRAL IOC 1
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See page 5-269
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