Motor protection breaker, 630 A, LSI, with UVR
Overload protection Ir is adjustable from 250 A to 630 A, short-circuit protection Isd from 3 to 15 × Ir, and instantaneous Ii fixed at 15 × In. Breaking capacity hits Icu = 55 kA at 415 V — enough headroom for most industrial distribution panels feeding motor control centers.
Below that, the breaker still coordinates selectively with downstream devices. The ETU350M is a microprocessor-based trip unit with LSI curves: Long-time (overload), Short-time (short-circuit with delay), and Instantaneous. The adjustable Ir from 250 A to 630 A lets you match the motor full-load current exactly, while Isd and Ii settings provide coordination with downstream contactors and starters. The UVR at 24 V DC means the breaker drops out on control-power loss — verify polarity on the UVR coil before wiring.
Panel integration
The nut keeper kit simplifies terminal tightening on the load side — no loose hardware to drop into live gear. The UVR terminals are clearly marked; keep the control wiring separate from the power conductors to avoid induced noise on the 24 V DC line.