GE 745 Instruction Manual page 152

S4 ELEMENTS
5.6.3.5 Fifth harmonic inhibit

5th HARM []
INHIBIT
5–56
FIGURE 5–12: Energization sensing scheme logic
PATH: SETPOINTS S4 ELEMENTS

5th HARMONIC INHIBIT
FUNCTION: Enabled
HARMONIC AVERAGING:
MESSAGE
Disabled
5th HARMONIC INHIBIT
MESSAGE
LEVEL: 10.0% fo
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
exceeds the harmonic inhibit level setting. With harmonic averaging enabled, all three
phases are inhibited if the three-phase average of the 5
setting.
• HARMONIC AVERAGING: Select "Enabled" to use the three-phase average of the 5th
harmonic current against the harmonic inhibit setting.
DIFFERENTIAL 5th HARM INHIBIT
 
Range:
Range:
Range:
th
harmonic of the same phase
th
harmonic exceeds the level
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTS
Enabled, Disabled
0.10 to 0.50 x CT in steps of
0.01
0.1 to 65.0% f in steps of 0.1
0