Choosing and Using a Two-Pole Voltage Tester Safely

What is a two-pole voltage tester?

A two-pole voltage tester has two probe bodies joined by a cable, carrying the contacts L and N. It is held directly between two points and shows the voltage between them without needing an earth reference through the user. That is exactly what sets it apart from a single-pole phase tester, which is regarded as unreliable and is not permitted for proving dead.

The reading is shown by an LED or LCD row and usually by a switchable load that makes the result mechanically and visually unmistakable. Modern instruments test AC and DC, detect polarity, show phase rotation and work over the full range without a battery.

What matters when choosing one?

The key factors are test range, measurement category and the type of indication. The tester must match the nominal voltage and the location of the installation and be built to EN 61243‑3.

• Category: CAT III for fixed installations, CAT IV for the supply area ahead of the main distribution board.
• Rated voltage to suit the installation, commonly up to 1000 V AC and 1500 V DC.
• Battery-free display of the voltage steps so the tester still works with a flat battery.
• One-hand operation, illuminated display and long enough probe tips with finger guards.
• GS mark and conformity with EN 61243‑3 confirmed on the device.

What are the five safety rules?

Before working on electrical installations the five safety rules to EN 50110‑1 apply. They are carried out in a fixed order, and the two-pole voltage tester is used at the third rule.

• Disconnect: isolate the installation from supply on all poles.
• Secure against reconnection: remove the fuse, lock off the switch, fit a warning sign.
• Prove dead: measure on all poles with the two-pole voltage tester.
• Earth and short-circuit: for high voltage and wherever required.
• Cover or barrier off adjacent live parts.

Proving dead is done on all poles, that is between all line conductors and against neutral and protective earth. Only when no combination shows voltage may the installation be treated as dead and released for work.

How are testers tested and cared for?

A voltage tester is a safety tool and is inspected accordingly at intervals. A visual and function check is made before every use, plus a recurring inspection of the portable equipment.

• Visual check for cracks in the housing, damaged cable and intact finger guards.
• Function test on a known voltage before and after every proving-dead.
• Document the recurring inspection as electrical equipment.
• Store dry and clean, withdraw faulty units immediately.

Frequently asked questions