GE TRANSFORMER MANAGEMENT RELAY 745 Instruction Manual page 97

5 SETPOINTS
e) 5TH HARMONIC INHIBIT
PATH: SETPOINTS S4 ELEMENTS
5th HARM INHIBIT
[ENTER] for more
th
The 5 harmonic inhibit feature of the percent differential element allows inhibiting the percent differential during intentional
overexcitation of the system. This feature inhibits the percent differential element in a particular phase if the 5
the same phase exceeds the harmonic inhibit level setting. With harmonic averaging enabled, all three phases are inhibited
if the three-phase average of the 5
• HARMONIC AVERAGING: Select "Enabled" to use the three-phase average of the 5th harmonic current against the
harmonic inhibit setting.
• 5th HARMONIC INHIBIT LEVEL: Enter the level of 5th harmonic current above which the percent differential element
will be inhibited from operating.
GE Multilin
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DIFFERENTIAL 5th HARM INHIBIT
ð
5th HARMONIC INHIBIT
ENTER
FUNCTION: Enabled
ESCAPE
HARMONIC AVERAGING:
ESCAPE
Disabled
MESSAGE
5th HARMONIC INHIBIT
ESCAPE
LEVEL: 10.0% f0
MESSAGE
th
harmonic exceeds the level setting.
Figure 5–12: 5TH HARMONIC INHIBIT SCHEME LOGIC
745 Transformer Management Relay
5.6 S4 ELEMENTS
Range: Enabled, Disabled
Range: 0.10 to 0.50 x CT in steps of 0.01
Range: 0.1 to 65.0% f in steps of 0.1
0
th
harmonic of
5
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