GE AKD-10 - Voltage-Specific Breaker Selection

26
M
ain Feeder circuit breakers
F
ully rated or Zone
selective Selective selective Fully rated
Table 26.2 240 volts, three phase
T
ransformer
r
ating 3-phase Max short-circuit Full load
S
hort-circuit rating sym current (A)
kVA and MVA available continuous Long-time inst. Long-time
impedance from primary current Transformer 100% or long-time Long-time short-time Long-time
p
ercent system (amperes)
À Â
a
lone Motor load Combined short-time
À
s
hort-time inst. inst.
5
0 14200 17100
100 15000 17900
300
150 15400 18300
4
.5%
Á
250 722 15600 2900 18500 WPS-08 WPS-08 WPS-08 WPS-08
500 15800 18700
7
50 15900 1
8800
Unlimited 16000 18900
50 21900 26700
1
00 24100 28900 WPS-08
500
150 24900 29700
4.5%
Á
250
1203 25600 4800 30400 WPS-16 WPS-08 WPS-08
500 26100 30900
WPH-08
750 26300 31100
Unlimited 26700 31500
50 24900 32100
100 27800 35000
750
150 1804 28900 36100
5.75%
250
 (2526) 29800 7200 37000 WPS-20 WPH-08 WPS-08 WPS-08
500 30600 37800
750 30800 38000
Unlimited 31400 38600
50 31000 40600 WPH-08 WPS-08 WPS-08
100
35600 45200
1000
150 2406 37500 47100 WPH-08 WPH-08
5.75%
250
 (3368) 39100 9600 48700 WPS-32 WPX-08
500
40400
50000
750 40900 50500 WPX-08 WPX-08
Unlimited
41800
51400
50 41200 55600
WPX-08
WP
X-08 WPX-08
100 49800 64200
1500
150 3608 53500 67900
5.75%
250
 (5052) 56800 14400 71200 WPS-40
500 59600 74000 WPH-32 WPS-32 WPS-32
750
60600
75000
Unlimited
62800
77200
50 49300 68500
WPH-32 WPS-32 WPS-32
100
62100
81300
2000
150 67900 87100
5.75%
250 4811 73500 19200 92700 WPS-50
500
78200 97400
WPX-32 WPH-32 WPH-32
750
 (6735) 80000 99200
Fused
Unlimited 83700 102900
br
eak
er
À With transformer operating on base temperature rise, without fans. Larger frame
size main br
eaker may be required when dual temperature rise for forced cooled
transformers are used.
Á Minimum impedance.
 Maximum forced cooled rating indicated in parentheses.
L = Long-time delay trip (overload tripping)
S
=
Short-time delay trip (selective fault tripping)
I
=
Instantaneous trip (high fault curr
ent fast tripping)
Table 26.1 Transformer forced cooled ratings
S
elf-cooled
Transformer type kVA % increase with fans
L
iquid filled: 65° C rise 750-2000 15%
2500-5000 25%
L
iquid filled: 55/65° C rise 750-2000 15% (fans) + 12% (65° C)
2500-5000 25% (fans) + 12% (65° C)
V
entilated dry 750-2500 33%
C
ast coil 500-2500 40%
3
000-5000 25%
LS
LS LSI LI
L
I
L
I
F
ully rated
arrangement
Selectively
coordinated
a
rrangements
Distribution or motor control center