4.19
Date Code 20080918 Instruction Manual SEL-749M Relay
Protection and Logic Functions
Basic Motor Protection
Figure 4.9 Phase Reversal Element Logic
0.5 s
0
47T
E47T = Y
Voltage Option = Y
DELTA_Y = Wye
|VA|
|VB|
|VC|
|VAB|
|VBC|
60 V
0.5 • |V2|
0.25 • FLA
min
|V1|
|IA|
|IB|
|IC|
0.5 • |I2|
|I1|
35 V
Relay
Word
Bits
Relay
Inputs
I1, V1 and I2, V2 indicate positive-sequence
and negative-sequence quantities.
FLA
min
= Lowest Full Load Current Setting Allowed
Relay
Inputs
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