The C25N3TM250C is a Schneider Electric ComPacT NSX250N moulded-case circuit breaker (MCCB) with a TM-D thermal-magnetic trip unit, rated 250 A at 50 °C in a 3-pole configuration. It sits in the ComPacT NSX family, which is the workhorse distribution and protection platform for commercial and industrial switchboards.
Breaking capacity — what the N code means for your fault level
The N breaking capacity code (50 kA at 415 V AC) is the mid-range option in the NSX line — above the B (25 kA) and below the S (70 kA) and H (100 kA) frames. At 220/240 V the breaker clears 90 kA Icu; at 440 V it holds 50 kA; at 500 V it drops to 36 kA; at 525 V to 35 kA; at 660/690 V it still clears 10 kA. This means the C25N3TM250C is sized for a 415 V distribution board with a prospective short-circuit current up to 50 kA — common for transformer-fed main switchboards in commercial or light industrial installations. If your site fault level exceeds 50 kA at 415 V, step up to the S or H frame.
The 105 mm width, 161 mm height, and 86 mm depth fit standard NSX cutouts and busbar connection patterns. The toggle control is manual; no rotary handle or motor mechanism on this variant.
Durability and thermal management
Mechanical durability is rated at 20,000 cycles; electrical durability varies with load — 20,000 cycles at 440 V at half rated current (In/2), 10,000 cycles at full In, and 5,000 cycles at 690 V full In. The IP40 front face and IK07 impact resistance handle typical switchboard service conditions.