Solar-string molded case circuit breaker
The 36 kA breaking capacity at 800 V AC (performance level F) gives headroom for high-fault solar combiner boxes and inverter-side protection where available fault current runs high.
Above that, thermal derating applies — the TM-D unit has a thermal memory, so repeated overloads accumulate heat and shorten the trip time on the next event. This matters for solar strings where partial shading can cause sustained overcurrents below the magnetic threshold. Category A utilisation confirms it is not intended for cascaded selectivity with downstream breakers — coordination must be achieved through selective coordination studies, not built-in delay. Mechanical durability of 20,000 cycles and electrical durability of 4,000 cycles at rated voltage give a realistic service life for a distribution breaker that sees occasional switching, not daily motor starts. Power dissipation of 9 W per pole (27 W total at rated load) must be factored into enclosure thermal calculations, especially in sealed outdoor combiner boxes.
Connection pitch is 40 mm, matching standard busbar spacing for 3-pole breakers in panelboards. Mounting position is flexible — horizontal or vertical — which helps in tight enclosures where busbar orientation varies. Dimensions of 120 x 205 x 105 mm (W x H x D) fit standard MCCB cutouts in sheet-metal panels.