Are the iC60H miniature circuit breakers suitable for use on a DC system?

Yes
The standard iC60H miniature circuit breakers are suitable for use on DC systems IEC/EN 60947-2.

1 pole 48Vdc 20kA
1 pole 72Vdc 10kA
2 pole 133Vdc 10kA (in series)
3 pole 133Vdc 20kA (in series)
4 pole 250Vdc 10kA ( in series )

However we also manufacture a specific range of C60-DC ( A9Nxxx ) suitable for use on a DC system which has a higher performance.

1 pole 220Vdc 10kA
2 pole 250Vdc 20kA
2 pole 440Vdc 10kA
2 pole 500Vdc 6kA

Released for:Schneider Electric Ireland