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Undervoltage Release (UVR)

The undervoltage release (UVR) is an optional device on both manually and electrically operated Magnum and NRX circuit breakers. It opens the circuit breaker when its supply voltage falls to between 35–60% of rated voltage. If the release is not energized to 85% of its supply voltage, the circuit breaker cannot be closed electrically or manually. The opening time is 70ms.

The UVR operates instantaneously and will not ride through power blips. There is a time delay UVR that mounts externally to the breaker.

If installed, this accessory MUST be wired. If left un-wired, the breaker will not be able to close, as the UVR will never see the required voltage to energize.

Magnum UVR:


Magnum renewal parts

NRX renewal parts