GE 745 Instruction Manual page 185

CHAPTER 5: SETPOINTS
5.6.12.3 Harmonic Derating
 W1 HARMONIC
DERATING
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
PATH: SETPOINTS S4 ELEMENTS


[ ] W1 HARM DERATING
FUNCTION: Disabled
W1 HARM DERATING
MESSAGE
RLYS (1-8): --------
W1 HARM DERATING
MESSAGE
TARGET: Self-Reset
MINIMUM OPERATING
MESSAGE
CURRENT: 0.10 x CT
W1 HARM DERATING
MESSAGE
PICKUP: 0.90
W1 HARM DERATING
MESSAGE
DELAY: 10 s
W1 HARM DERATING
MESSAGE
BLOCK: Disabled
• MINIMUM OPERATING CURRENT: Enter the minimum value of current (in units of relay
nominal current) required to allow the harmonic derating element to operate.
• W1(3) HARMONIC DERATING PICKUP: Enter the harmonic derating below which the
winding 1(3) harmonic derating will pickup and start the delay timer.
• W1(3) HARMONIC DERATING DELAY: Enter the time that the harmonic derating must
remain below the pickup level before the element operates.
FIGURE 5–38: THD level scheme logic
HARMONICS
 
S4 ELEMENTS
W1(3) HARMONIC DERATING
Range: Enabled, Disabled
Range: 1 to 8
Range: Self-Reset, Latched, None
Range: 0.03 to 1.00 x CT in steps of
0.01
Range: 0.01 to 0.98 in steps of 0.01
Range: 0 to 60000 s in steps of 1
Range: Logc Inpt 1 to 16, Virt Inpt 1 to
16, Output Rly 2 to 8, SelfTest
Rly, Vir Outpt 1 to 5, Disabled
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