GE 745 - 5.6.12.3 Harmonic Derating

CHAPTER 5: SETPOINTS S4 ELEMENTS
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL 5–89
FIGURE 5–38: THD level scheme logic
5.6.12.3 Harmonic Derating
PATH: SETPOINTS  S4 ELEMENTS  HARMONICS  W1(3) HARMONIC DERATING
• 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.
 W1 HARMONIC []
DERATING
W1 HARM DERATING
FUNCTION: Disabled
Range: Enabled, Disabled
MESSAGE
W1 HARM DERATING
RLYS (1-8): --------
Range: 1 to 8
MESSAGE
W1 HARM DERATING
TARGET: Self-Reset
Range: Self-Reset, Latched, None
MESSAGE
MINIMUM OPERATING
CURRENT: 0.10 x CT
Range: 0.03 to 1.00 x CT in steps of
0.01
MESSAGE
W1 HARM DERATING
PICKUP: 0.90
Range: 0.01 to 0.98 in steps of 0.01
MESSAGE
W1 HARM DERATING
DE L AY: 1 0 s
Range: 0 to 60000 s in steps of 1
MESSAGE
W1 HARM DERATING
BLOCK: Disabled
Range: Logc Inpt 1 to 16, Virt Inpt 1 to
16, Output Rly 2 to 8, SelfTest
Rly, Vir Outpt 1 to 5, Disabled