Alstom SHPM 101 - Typical SOTF Trip Times for Close up 3 Phase and Single Phase Faults

SERVICE MANUAL R5888C
QUADRAMHO Chapter 2
Page 74 of 74
Fault Source SW1 to left SW1 to right
type impedance any Z1/Z2/Z3 Current No Volts
(ohms)
Line VT Busbar VT Line VT Busbar VT
SOTF TRIP TIMES (ms)
Min Max Min Max Min Max Min Max
A–B–C–G 108 29 35 16 22 30 36 39 45
36 30 35 14 22 30 37 40 46
4 2932142130343844
A–G 108 29 27 21 32 32 38 36 50
Quad’l 36 28 37 21 33 32 41 38 49
relay 4 28 34 22 29 31 38 38 49
A–G 108 27 38 17 26 32 38 36 50
Mho 36 30 34 16 26 32 41 38 49
relay 4 28 37 14 28 31 38 38 49
Table 10: Typical SOTF trip times for close up 3 phase and single phase faults.
Relay settings: Z
Ph
=Z
N
= 4.8Ω
θ
Ph
= θ
N
=85°
Z1 multiplier = 1
Z2 multiplier = 2
Z3 multiplier = 3