81
3
Selection and application
3-13 MCCBs for DC circuit applications
Table 3-27 MCCBs DC line up
Rated voltage
Frame size
25/32
50
63
100/125
160
200/250
400
630
800
DC
125V
BW32SBG
BW50SBG
BW63SBG
10/10
10/10
10/10
250V
BW50EAG
BW63EAG
"7%!1
BW100EAG
BW160EAG
BW250EAG
BW400EAG
BW630EAG
BW800EAG
C2
C2
C2
2.5/2
2.5/2
5/3
10/5
10/5
20/10
20/10
20/10
BW32SAG
"73!1
BW50SAG
"73!1
BW63SAG
"73!1
BW125JAG
"7*!1
□
C2
BW160JAG
BW250JAG
"7*!1
□
C2
BW400SAG
C2
C2
C2
2.5/2
5/3
5/3
15/8
20/10
20/10
20/10
BW50RAG
BW63RAG
BW125RAG
"72!1
□
C2
BW160RAG
BW250RAG
"72!1
□
C2
BW400RAG
"72!1
□
C2
BW630RAG
"72!1
□
C2
BW800RAG
"72!1
□
C2
C2
C2
5/3
5/3
40/20
30/15
30/15
40/20
40/20
40/20
BW50HAG
BW125HAG
BW250HAG
BW400HAG
"7(!1
□
C2
BW630HAG
"7(!1
□
C2
BW800HAG
"7(!1
□
C2
40/20
40/20
40/20
40/20
40/20
40/20
400V
BW32SAG
BW50SAG
BW63SAG
BW100EAG
-3P
C4
-3P
C4
-3P
C4
-3P
C4
2.5/-
2.5/-
2.5/-
5/-
500V
BW400EAG
BW630EAG
BW800EAG
-3P
-3P
-3P
20/-
20/-
20/-
BW125JAG
BW250JAG
BW400SAG
-3P C5
-3P
C5
-3P
10/-
10/-
20/-
BW125RAG
BW250RAG
BW400RAG
BW630RAG
BW800RAG
-3P
C5
-3P
C5
-3P
-3P
-3P
20/-
20/-
40/-
40/-
40/-
BW400HAG
BW630HAG
BW800HAG
-3P
-3P
-3P
40/-
40/-
40/-
600V
BW125JAG
BW250JAG
-3P CP
-3P CP
3/-
3/-
BW 50SBG
BW 63SBG
BW 125RAG
BW 250JAG
BW 400RAG
BW 630RAG
BW 800RAG
-3P C6
-3P C6
-4P C6
-4P C6
-4P
-4P
-4P
10/-
10/-
25/-
25/-
40/-
40/-
40/-
BW 250RAG
BW 400HAG
BW 630HAG
BW 800HAG
-4P C6
-4P
-4P
-4P
40/-
40/-
40/-
40/-
750V
BW 400RAG
BW 630RAG
BW 800RAG
-3P CP
-3P CP
-3P CP
10/5
10/5
10/5
1000V
BW 400RAG
BW 630RAG
BW 800RAG
-4P CP
-4P CP
-4P CP
5/5
5/5
5/5
Note: If there is no DC-specific model code such as “C2,” “C5” and “C6” at the end of the type description, a standard product can be used for both AC and DC. Only DC250V is indicated for
DC rating (DC125V is indicated for BW32SBG, BW50SBG and BW63SBG). For those adjusted to DC circuit, please specify “C2” (DC250V rating), “C5” (DC500V rating), or “C6” (DC600V
rating) at the end of the type description.
Upper row : Type
Lower row:breaking capacity Icu/Ics(kA)
The minimum
operating current at
DC is
about 110–140% of
that for AC.
The instantaneous trip
current is higher than
that for an AC circuit.
The rate of variation
depends on the
ampere-frame size,
rated current and
model. The trip
current can be as high
as 140% of the AC
value.
Instantaneous trip
characteristics
Inverse time-delay
trip characteristic
Trip
device
Operating
characteristic curve
Not applicable
None
Solid state
Operating characteristic changes for DC circuit application
Thermal-
magnetic
Hydraulic-
magnetic
AC
DC
Current
Operating time
AC
DC
Current
Operating time
3-13 MCCBs for DC circuit applications
While MCCBs are designed for an AC circuit, some may be
used in a DC circuit. The DC rating is cited in the catalog for
those applicable to a DC circuit. If a MCCB adjusted for AC is
to be used in a DC environment, the operating characteristics
will change as indicated in the table on the right. Therefore,
FAB adjusted for DC shall be used for a DC load. Further, due
to the absence of a zero-crossing point, it is more difficult to
break a DC current than an AC current in high-voltage levels.
Therefore, standard products cannot be used.
In such a case, it is necessary to use a breaker dedicated for
use with a DC high voltage.
ELCB cannot be used because it cannot detect leakage of DC
current.