Neutral Earth Links: Applications, Standards, and Specification Guide

A neutral earth link (also called a neutral-earth bridge, MEN link, or N-E link) is a short, removable conductor that electrically connects the neutral busbar to the earth (ground) busbar at a specific point in an electrical distribution system. It is a critical safety component in earthing systems that use the multiple earthed neutral (MEN) architecture.

In most domestic, commercial, and light industrial electrical installations, this connection is made at the main distribution board (MDB) or at the point where the supply authority's neutral connects to the installation's earth conductor. The link ensures that the neutral and earth conductors share a common reference potential at the supply origin, allowing protective devices (fuses, circuit breakers, RCDs) to operate correctly under fault conditions.

In a multiple earthed neutral (MEN) system — the standard earthing arrangement in the UK, Australia, New Zealand, India, and many other countries — the supply authority earths the neutral at multiple points along the distribution network. At the consumer's installation, a single neutral-earth link at the main switchboard creates the local earth reference for the installation.

The significance of the link being removable is that electricians can disconnect the neutral from earth for testing purposes — particularly when testing insulation resistance (megger testing) of the installation, where the N-E connection would short-circuit the test instrument. After testing, the link must be replaced before energising the installation.

• Solid (non-removable) neutral earth link — a fixed conductor, usually a flat brass or copper bar bolted between the neutral and earth bars; used where the connection is permanent and testing is done by other means
• Removable link — designed to be easily disconnected for insulation testing; typically has a single screw or bolt securing the link, with a warning label indicating its function
• Link with test point — includes a terminal or probe point that allows voltage measurements to verify the N-E connection without removing the link
• DIN rail-mounted link — modular link designed to clip onto standard DIN rail and bridge adjacent N and E busbars in modular distribution boards

• Main distribution boards (MDB) — the primary application; the N-E link is usually located at the supply incomer position
• Sub-distribution boards and sub-boards — where a local earth is derived from the neutral at a sub-panel
• Consumer units — domestic-scale distribution boards, where the link connects the neutral bar to the earth bar at the main switch
• Switchgear panels — industrial switchgear cabinets with neutral and earth bus systems
• Generator and UPS systems — where an earthed neutral is required at the output
• Temporary power installations — portable distribution units where the MEN link ensures correct earth reference

When ordering custom neutral earth links, provide the following information:

• Current rating — maximum continuous current the link must carry (determines cross-sectional area)
• Material — copper or brass; with or without plating
• Plating — tin, nickel, or natural
• Overall dimensions — length × width × thickness, or span between hole centres
• Hole diameter and pitch — to match the neutral and earth bar bolt pattern
• Mounting method — flat bar, bolt-through, DIN rail, or screw terminal
• Applicable standard reference if required