Shunt release NZM4-XA208-250AC/DC 266451

What is it and what is it used for

The NZM4-XA208-250AC/DC shunt release is a control element that enables remote switching-on of a power circuit breaker by applying a control voltage – both alternating (AC) and direct (DC). It has no contacts, does not detect current, and does not function as a protective device. It operates solely as a pulse actuator: when a voltage in the range of 208–250 V is applied to its terminals, the release activates the closing mechanism of the main switch. Once the voltage is removed, the mechanism remains in the ON position. It does not disconnect the circuit.

How it works and where it is installed

It is mounted directly onto NZM4(-4) or N(S)4(-4) series circuit breakers. Electrical connection is made via a screw terminal – no additional wires or connectors are required. It cannot be installed together with an undervoltage release (NZM..-XU...) or a pre-closing auxiliary contact (NZM..-XHIV..). All these components operate on the same control path; their simultaneous presence would cause a conflict.

When the release is energized, the mechanism prevents accidental contact with the main terminals during switching-on attempts, providing an additional safety layer for the installer. No current setting is required – its tripping range is 0 A, as it is not a protective device. Its sole function is to "push" the circuit breaker mechanism into the ON position.

Why this solution makes sense

• Operates on AC and DC – no need to choose between alternating or direct voltage. As long as the voltage is within the 208–250 V range, frequency (50 Hz or 60 Hz) is irrelevant.
• No configuration required – with no current settings, there is nothing to adjust. It works immediately after connection.
• Compatible with the modular NZM system – integrates seamlessly with existing Eaton solutions without requiring replacement of the entire device.
• Safe for operation – mechanical blocking prevents contact with terminals during activation, reducing the risk of electric shock during live work.
• Not suitable for motors or relays – this is neither an overload protection device nor a short-circuit release. It is purely a control element. If protection is required, use an appropriate motor circuit breaker or relay.

If you already have an NZM4 and wish to add remote switching via a signal from a control panel or automation system, this component is exactly what you need.