TERASAKI TemBreak 2 - Connecting DC Circuit Breakers

4-2
Connection of conductors to DC circuit breakers
It is more difficult to interrupt DC current than AC current because DC current does not have a zero point. Therefore for high
DC voltages, 3-pole or 4-pole circuit breaker main contacts are connected in series to ensure breaking performance. As
illustrated below, the main power conductors for DC-use air circuit breakers, moulded case circuit breakers, and switch
disconnectors shall be connected generally as shown below but also depending on the type of breaker, the number of poles,
and the DC operating voltage.
Type of breakers
No.s of
poles
Applicable
voltage
(V)
Non-grounded system
(Protection + Isolation function)
Applicable
voltage
(V)
Ordinally
connection
Source
Load
Source
Load
Source
Load
Reverse
connection
Load
Source
Source
Load
Source
Load
Applicable
voltage
(V)
S1000-ND
✽：2 poles breaker is a 3 pole breaker with the center pole omitted.
2P
≦250 ≦250 ≦150
Grounded system
(Protection)
Grounded system
(Protection + Isolation function)
Rated breaking
capacity
I
cu
/ I
cs
Rated breaking
capacity
I
cu
/ I
cs
Rated breaking
capacity
I
cu
/ I
cs
50kA/20kA 50kA/20kA 50kA/20kA
Type of breakers
No.s of
poles
Applicable
voltage
(V)
Non-grounded system
(Protection + Isolation function)
Applicable
voltage
(V)
Ordinally
connection
Source
Load
Source
Load
Source
Load
Applicable
voltage
(V)
XS3200ND
✽：2 poles breaker is a 3 pole breaker with the center pole omitted.
2P
≦250 ≦250 ≦150
Grounded system
(Protection)
Grounded system
(Protection + Isolation function)
Rated breaking
capacity
I
cu
/ I
cs
Rated breaking
capacity
I
cu
/ I
cs
Rated breaking
capacity
I
cu
/ I
cs
50kA/30kA 50kA/30kA 50kA/30kA
XS1250ND 2P
≦250
50kA/30kA
≦250
50kA/30kA
≦150
50kA/30kA
XS1600ND 2P
≦250
50kA/30kA
≦250
50kA/30kA
≦150
50kA/30kA
XS2000ND 2P
≦250
50kA/30kA
≦250
50kA/30kA
≦150
50kA/30kA
XS2500ND 2P
≦250
50kA/30kA
≦250
50kA/30kA
≦150
50
kA/30kA
✽：2 poles breaker is a 3 pole breaker with the center pole omitted.