What causes a split neutral fault and why is it dangerous – Advice from Electriman, North London Electricians

## What Is a Split Neutral Fault?

A **split neutral fault** happens when the neutral wire in your electrical circuit breaks or becomes disconnected, while the live wire stays connected and energised. In a healthy circuit, current flows out through the live wire and returns safely through the neutral. When the neutral is broken, that return path is lost — and electricity can behave in very unexpected and dangerous ways.

### Why Is It So Dangerous?

Unlike a blown fuse or tripped breaker, a split neutral doesn't always cut the power. Instead, it can:

- Make **metal casing on appliances become live** at mains voltage (230V)

- Cause **lights to flicker, dim, or burn extremely bright** as voltage shifts unpredictably

- Allow **current to return through earth conductors or pipework**, creating hidden shock and fire risks

- Fool you into thinking a circuit is safe when it isn't

### Common Causes

- **Loose or corroded neutral terminal** at the consumer unit, junction box, or socket

- **Rodent damage** to cable insulation and conductors in roof spaces or underfloor areas

- **Old wiring** with aluminium neutrals that have corroded at terminations

- **Poor workmanship** — an undertightened screw terminal that has gradually worked loose

- **Mechanical damage** to cables during building works or DIY

### What You Might Notice

- Lights flickering or changing brightness for no obvious reason

- Appliances behaving erratically or failing

Need a qualified electrician in North London?

Electriman covers Mill Hill, Barnet, Finchley, Edgware, Enfield, Watford and surrounding areas. All work is Part P certified and fully insured.