Testing insulating mats per IEC 61111

An insulating mat that looks intact on visual inspection can break down in the dielectric test. Rubber ages, develops micro-cracks and absorbs moisture — all invisible, all dangerous. IEC 61111 describes the classes, test voltages and testing interval.

Classes and test voltages

The classes follow the same logic as IEC 60903 for gloves. The same voltage regime, a different test object and a different test setup.

Test procedure

1. Visual inspection

Check for cuts, punctures, blisters or structural deformation. Replace when in doubt. A mat is replaceable, a worker is not.

2. Record mat identification

Record the mat identification and class in the test report, so every measurement traces back to the right mat.

3. Electrode setup

Lay the mat flat with a top electrode (metal plate) and a bottom earthing electrode. Even contact across the whole surface is not optional here.

4. Ramp up the voltage

Raise the voltage gradually to the proof voltage for your class and hold the test voltage for the prescribed time. Watch for breakdown or flashover during the test.

5. Assessment

IEC 61111 has no leakage current limit. The mat passes if the test voltage holds for the full test time without breakdown or flashover. If breakdown occurs, the mat is rejected. For class 0, visual inspection suffices at re-test; the dielectric proof test applies from class 1.

6. Certification

Test report with date, mat identification, class, proof voltage and test result.

Test interval

IEC 61111: every 12 months for mats in use. Manufacturer, internal policy or national standards may prescribe a shorter term. After mechanical damage or an incident, re-test or discard immediately — do not wait for the next regular round.

More about testing high-voltage PPE

This article is part of a series on the periodic testing of high-voltage PPE:

• Testing insulating gloves — IEC 60903
• Testing hot sticks — IEC 60832-1 / 60855-1
• Testing voltage detectors — IEC 61243
• Testing phase comparators — IEC 61481-1
• Testing earthing equipment — IEC 61230

Or read the complete overview with all standards and intervals.