What this 4-pole 100 A MCCB covers
Its TM220 thermal-magnetic release provides fixed thermal pickup and magnetic short-circuit response — no field-adjustable trip unit, which simplifies ordering but means the breaker is matched to a specific load profile at the factory.
Interrupting capacity and thermal derating — the numbers that decide fit
The interrupting ratings drop as system voltage rises: 76 kA at 440 V, 17 kA at 500 V, and 17 kA at 690 V. That steep roll-off above 440 V means this breaker is sized for 400 V class systems (up to 440 V) where the 121 kA or 76 kA rating gives real fault-clearing headroom. Thermal derating is mild through 50 °C (still 100 A), then drops to 98 A at 55 °C, 96 A at 60 °C, 94 A at 65 °C, and 91 A at 70 °C.
The 101.6 mm width (4 inches) is standard for a 4-pole MCCB in this frame size — it occupies four 25.4 mm pole positions on the DIN rail or mounting plate. Front protection is IP40, so it's splash-resistant from the front but not sealed against hose-down; keep it inside a panel with a door. The 50 % N-conductor protection design means the neutral pole is rated at half the phase current (50 A in this case), which matches typical 3-phase + neutral feeder applications where the neutral carries only unbalanced load — not a full-capacity neutral for harmonic-rich loads like VFDs with significant triplen currents.