These breakers from MidNite Solar break their rated amperage load at 300 DC volts repeatedly and with no damage when. They have been evaluated by ETL to 300VDC and is listed for the U.S. and Canada. All of the NRTL listings still apply, making them suitable for use in the solar industry. All MidNite circuit breakers hold 100% rated current independent of ambient temperature.
Always use a properly sized breaker for disconnecting.