Test equipment

RCD Tester

Injects a known leakage current and times the trip — the only way to prove an RCD will actually save someone.

Real part — tap a marker

RCD Tester

Injects a known leakage current and times the trip — the only way to prove an RCD will actually save someone.

Rotary selector — IΔn, ×½, ×1, ×5 and the ramp test
Display — trip time in milliseconds
Test button — starts the injection
Mains lead — plugs into a socket on the circuit under test
Earth/loop ranges — Zs and, with the supply isolated, Ze and R1+R2
Polarity and wiring check before any test is allowed to run

🔧 Use it while you build

Terms used here

Defined in the glossary — each one opens at its own entry.

⚠ Safety note

An RCD tester connects to live parts by design, so the instrument, its lead and your hands are at supply voltage during the test. Never start a test with the circuit energised from an unknown source, and never use the ×5 range as a shortcut — 150 mA through a person-sized fault path is precisely what the device exists to prevent.

More tools

← Needle-Nose Pliers Side Cutters (Diagonal Cutters) →

Tool understood. Time to wire.

Run the real thing — a guided circuit, live current, and fault simulation in your browser.

Open ElectraSim Free Browse all tools →