MV design guide - Schneider Electric

Standards
IEC - ANSI comparison
100
90
70
50
10
Upeak (%)
tc
Onde coupée suivant ANSI
pour le matériel d'extérieur
t (µs)
According to ANSI
Rated Rated lightning Rated power frequency
voltage withstand voltage withstand voltage
(kV) (kV) 50 Hz 1 mm (kV)
Indoor equipment
4.16 60 19
7.2 95 36
13.8 95 36
38 150 80
Outdoor equipment
15.5 110 50
25.8 125 60
150
38 150 80
200
N.B.
c BIL: Basic Insulation Level
The outdoor equipment is tested with chopped waves.
c The impulse withstand is equal to:
1.29 BIL for a duration of tc = 2 µs
1.15 BIL for a duration tc = 3 µs
Rated normal current
According to IEC
c Values of rated current: 400 - 630 - 1250 - 1600 - 2500 - 3150 A
According to ANSI
c Values of rated current: 1200 - 2000 - 3000 A
Short-time withstand current
According to IEC
c Values of short-circuit rated breaking capacity:
6.3 - 8 - 10 - 12.5 - 16 - 20 - 25 - 31.5 - 40 - 50 - 63 kA
According to ANSI
c Values of short-circuit rated breaking capacity:
v indoor equipment: 12.5 - 20 - 25 - 31.5 - 40 kA
v outdoor equipment:
Class (MVA)
Breaking capacity (kA)
I at Umax
KI at Umin
250 29 36
350 41 49
500 18 23
750 28 36
1000 37 46
1500 21 35
2750 40 40
Schneider Electric
Merlin Gerin MV Design Guide
73