The SOL40B3A320 is a 3-pole EasyPact Solar MCCB from Schneider Electric, rated 320 A at 40 °C with a 25 kA breaking capacity at 800 V AC. For a solar combiner box or distribution panel feeding inverter outputs, that SCCR headroom means you don't need an upstream fuse to cover a high-fault scenario. The thermal-magnetic TM-D trip unit provides LI protection: L for overload (thermal, adjustable) and I for short-circuit (magnetic, fixed). The thermal memory means it remembers prior heating, so repeated overloads close together will trip faster, which matters for distribution circuits feeding intermittent loads like pump banks or compressor groups. It's rated for 800 V AC 50/60 Hz operation, with an insulation voltage (Ui) of 1250 V AC — that's the voltage the internal insulation system can withstand continuously, giving headroom for switching transients on a 600 V or 800 V solar array.
Mounting and integration in the panel
Fixed-mount MCCB with backplate mounting, 40 mm connection pitch between poles. The 40 mm pitch is standard for 3-pole MCCBs in this frame size; it fits the typical busbar spacing in a solar combiner or distribution panel. Mounts horizontally or vertically — no derating required for orientation. IP20 finger-safe protection on the front, so it's suitable for enclosed panels where operators don't need to access live parts. The grey (RAL 7015) housing is the standard EasyPact colour.
Suitability for isolation per EN/IEC 60947-2 — it can be used as a disconnecting means with a visible gap. Overvoltage category III, which covers fixed installation distribution boards.