The C25S4 is a ComPacT NSX250S basic frame — a 250 A moulded-case frame rated for distribution duty, built to EN/IEC 60947-2 and UL 60947-4-1. It ships without a trip unit, so you pair it with a separate electronic or thermal-magnetic trip module to set the actual protection curve. That is an S-break capacity class, typical for high-fault industrial switchboards where the available fault current exceeds 65 kA. The 690 V AC rated operational voltage and 800 V AC rated insulation voltage confirm it handles 480/600 V systems with margin, and the 8 kV impulse withstand covers surge environments typical of overvoltage category III and pollution degree 3.
Deployment context
This is a fixed-mount frame for backplate mounting — it bolts into a switchboard or panel enclosure, not a DIN rail. The 140 mm width and 161 mm height with 86 mm depth and a 35 mm connection pitch define the cutout and bus-bar spacing. The toggle control provides manual on/off and trip indication. Front-face Class II shock protection means no additional grounding of the front cover is required for operator safety.