Page 24 - Ferraz semiconductor BS88

Semiconductor fuses
Semiconductor (AC) fuses

®
Other Protistor Fuses
BS88-4 Fuses
000 BS88 - 500 V to 690 VAC

L/R (ms) DC Application data
Um (V)
100 d c b a
Rated
90 1400 Curve Ipm (A)
L/R =80 ms current
80 L/R =25 ms
1200 20 a 60
70
L/R =10 ms 25 a 65
60 1000 32 a 90
50 800 40 a 120
40 50 a 150
600 63 a 200
30 80 a 270
20 400 100 a 370
10 200 125 a 500
0 160 a 700
0 U (V) 0 200 b 1200
100 200 300 400 500 600 700 0 100 200 300 400 500 600 700 U (V) 250 c 1800
Above: curves indicate permissible value of time constant 315 c 2200
L/R as a function of DC working voltage. Above: Curves indicate peak arc 350 d 2600
Curve a: for ratings from 20 to 160 A voltage Um which may appear
Curve b : for ratings from 180 to 200 A across the fuse terminals at wor- 400 d 3100
Curve c : for ratings from 250 to 315 A king voltage U.
Curve d : for ratings from 350 to 400 A Ipm values give minimum DC inter-
rupting current in amps.
Current limitation curves
Watts loss
Below: Curves show, for each rating, value of peak let-through
I (A) current Ic as a function of available fault current Ip. Ip (A) P/Pn
C
10 5 400 A 0.9 1
Ic = 2.5 Ip gRB URB Ic = 2.5 Ip Ic = 2 Ip 350 A 0.8
315 A
250 A
200 A
0.7
160 A
10 4 Ic = 2 Ip 125 A 150 A 0.6
100 A
125 A
110 A
80 A
63 A
50 A 100 A 0.5
80 A
40 A 75 A 0.4
32A
25 A 0.3
20 A
3 0.2
10
0.1
0
0.5 0.6 0.7 0.8 0.9 1.0 1.1 I/In
2
10 Above: Curve enables computation of
10 10 3 10 4 10 5 10 6 10 2 10 3 10 4 10 5 10 6 power losses P for a IN-rated fuse as a
function of the R.M.S. current I (as a mul-
Time vs current characteristics tiple of IN for steady state operation)
t (s) 25 40 63 100 gRB t (s) 80 100 110 125 150 160 200 315 URB
20 32 50 80 125 75 250 350 400
10 4 10 4 Left: Curves
indicate, for
10 3 10 3 each rated
a= 130 a= 130 current, pre-
A2=0.6 A2=0.6 arcing time
10 2 B1= 1.25 10 2 B1= 1.25 vs. R.M.S.
B2= 0.6 B2= 0.6 pre-arcing
Cf3= 0.8 Cf3= 0.8
C C' current
10 10 C C'
1 1
10 -1 10 -1
Tolerance
10 -2 10 -2 for mean
pre-arcing
current ±
10 -3 10 -3 8%.
10 -4 10 -4
4
5
10 10 2 10 3 10 I (A) 10 10 2 10 3 10 4 10 I (A)
SCAC217
12/04