Main fuses, RCDs and consumer unit: a simple explanation

What’s inside your consumer unit and why it matters

Leafy Energy gives insight into energy usage and load, but the actual protection against overload and leakage takes place in your consumer unit. This article explains the key components in simple terms.

Main fuse

• Limits the maximum current your entire home can draw.
• Is managed by the grid operator and is not a DIY component.

RCD (Residual Current Device)

• Disconnects part of the installation when leakage current is detected.
• Protects against dangerous fault currents to earth.

Circuit breakers

• Divide the installation into separate circuits (for example kitchen, attic, charger).
• Trip when that specific circuit is overloaded or shorted.

Leafy Energy can show which loads contribute to stress on a circuit, but changing circuits or fuses is work for a licensed electrician.