19
Air Circuit Breakers
BT2 series
0.4
1
10
0.001
0.1
0.2
1
100
1000
10000
100000
t (s)
0.3
0.4
1.6
15
kA
I
r1
80
10
0.01
I
r1
t
1
long-time delay curve
I
r2
I
2
T ON
Short-time delay curve
t
2
I
2
T OFF
Instantaneous curve
Instantaneous range
Instantaneous
range
I
r3
= 1.6kA~35kA+OFF BT2-1600
2kA~50kA+OFF BT2-2000
2.5kA~50kA+OFF BT2-2500
4kA~65kA+OFF BT2-4000
6.3kA~80kA+OFF BT2-6300
The range of short-time delay
I
r2
=(0.4~15)In+OFF
t
2
=0.1s~0.4s
The range of long-time delay
I
r1
=(0.4~1)In
t
1
=60s~1440s
Illustrational curve
Characteristic curve
Characteristic curve of high-voltage fuse I
4
t
• T/I (time / current) curve of type 25 and 26 intelligent controllers (OCR)
