49
3
Selection and application
3-3 Selective trip applications
High-voltage fuse
JC type
Transformer
6/0.42kV
MCCB
● 3 φ 6.3kV/420V
Capacity (kVA)
100
200
300
500
750
1000
Secondary current (A)
137
275
412
687
1031
1375
Secondary short-circuit current (kA)
3.4
6.9
10.3
17.2
25.8
34.4
JC type power fuse rated current (A)
20
30
50
60
75
100
MCCB type
ELCB type
CB breaking
capacity (kA)
CB rated current (A)
BW32AAG– (2,3)P
○○○
EW32EAG–3P
○○○
1.5
5 to 32
*
*
*
*
*
*
BW50AAG– (2,3)P
○○○
EW50AAG– (2,3)P
○○○
5 to 50
*
*
*
*
*
*
BW32SAG– (2,3)P
○○○
EW32SAG–3P
○○○
2.5
3, 5 to 32
*
*
*
*
*
*
BW50EAG– (2,3)P
○○○
EW50EAG–3P
○○○
5 to 50
*
*
*
*
*
*
BW63EAG– (2,3)P
○○○
EW63EAG–3P
○○○
60, 63
*
*
*
*
*
*
BW50SAG– (2,3)P
○○○
EW50SAG–3P
○○○
7.5
5 to 32
*
*
*
*
BW63SAG– (2,3)P
○○○
EW63SAG–3P
○○○
60, 63
*
*
*
*
BW50RAG– (2,3)P
○○○
EW50RAG–3P
○○○
10
10 to 50
*
*
*
*
BW63RAG– (2,3)P
○○○
EW63RAG–3P
○○○
60, 63
*
*
*
*
BW100EAG– (2,3)P
○○○
EW100EAG–3P
○○○
50, 60, 63, 75, 100
*
*
*
*
BW125JAG– (2,3)P
○○○
EW125JAG– (3,4)P
○○○
30
15 to 75
*
BW125RAG– (2,3)P
○○○
EW125RAG– (3,4)P
○○○
50
BW125JAG– (2,3)P
○○○
EW125JAG– (3,4)P
○○○
30
100 to 125
BW125RAG– (2,3)P
○○○
EW125RAG– (3,4)P
○○○
50
BW250EAG– (2,3)P
○○○
EW250EAG–3P
○○○
18
125
*
*
BW250JAG– (2,3,4)P
○○○
EW250JAG– (3,4)P
○○○
30
*
BW250RAG– (2,3,4)P
○○○
EW250RAG– (3,4)P
○○○
50
BW250EAG– (2,3)P
○○○
EW250EAG–3P
○○○
18
150 to 250
*
*
BW250JAG– (2,3,4)P
○○○
EW250JAG– (3,4)P
○○○
30
*
BW250RAG– (2,3,4)P
○○○
EW250RAG– (3,4)P
○○○
50
BW400EAG– (2,3)P
○○○
EW400EAG–3P
○○○
30
250
*
BW400SAG– (2,3)P
○○○
EW400SAG–3P
○○○
36
BW400RAG– (2,3,4)P
○○○
EW400RAG– (3,4)P
○○○
50
BW400HAG– (2,3,4)P
○○○
EW400HAG– (3,4)P
○○○
70
BW400EAG– (2,3)P
○○○
EW400EAG–3P
○○○
30
300
BW400SAG– (2,3)P
○○○
EW400SAG–3P
○○○
36
BW400RAG– (2,3,4)P
○○○
EW400RAG– (3,4)P
○○○
50
BW400HAG– (2,3,4)P
○○○
EW400HAG– (3,4)P
○○○
70
BW400EAG– (2,3)P
○○○
EW400EAG–3P
○○○
30
350, 400
*
BW400SAG– (2,3)P
○○○
EW400SAG–3P
○○○
36
BW400RAG– (2,3,4)P
○○○
EW400RAG– (3,4)P
○○○
50
BW400HAG– (2,3,4)P
○○○
EW400HAG– (3,4)P
○○○
70
BW630EAG–3P
○○○
EW630EAG–3P
○○○
36
500, 600, 630
BW630RAG–3P
○○○
EW630RAG–3P
○○○
50
BW630HAG–3P
○○○
EW630HAG–3P
○○○
70
BW800EAG–3P
○○○
EW800EAG–3P
○○○
36
700, 800
BW800RAG–3P
○○○
EW800RAG–3P
○○○
50
BW800HAG–3P
○○○
EW800HAG–3P
○○○
70
Note: 2 or 3 poles are entered for (2, 3), 3 or 4 poles are entered for (3, 4) and 2, 3 or 4 poles are entered for (2, 3, 4). The 3-pole 30A molded-case circuit breaker is
described as BW50AAG–3P030. The rated current described as “3A” is the rating applicable to a molded-case circuit breaker only.
Range that may exceed the allowable
time-current range of the fuse
3-3-3 Selective trip coordination with a high-voltage fuse
This section describes selective trip coordination for a transformer primary-side high-voltage fuse and a
secondary-side molded case circuit breaker or earth leakage circuit breaker. The applicable range, however,
is within the short-circuit current determined by the transformer capacity and percentage of impedance for
the breaking capacity of the molded case circuit breaker or earth leakage circuit breaker. (Use caution for
the ranges marked with an asterisk (*).) This gives the secondary short-circuit current that is assumed to
have an impedance percentage of 4% of the transformer depending on the conditions of short-circuit current
calculation.