Line protection with a 500 A frame and ETU550 trip unit
Its ETU550 electronic trip unit allows adjustable long-time pickup and delay settings, with an adjustable response value time tr max. of 20 seconds, giving the integrator fine-grained coordination for feeder or main breaker duty.
Breaking capacity is 187 kA at 240 V, 121 kA at 415 V, 55 kA at 440 V, 36 kA at 500 V, and 9 kA at 690 V. At 240 V this MCCB handles high-fault utility feeds; at 690 V the 9 kA figure still covers most industrial motor branch circuits. The 6 kA limited short-time rating (1 s and 0.5 s) supports selective coordination downstream.
At 55 °C it carries 477 A, at 60 °C it carries 455 A, at 65 °C it carries 432 A, and at 70 °C it carries 410 A. The 110 mm depth fits standard 400 mm deep enclosures; the 138 mm width and 248 mm height leave room for side-mounted accessories or adjacent breakers on a busbar stack.