How to Choose the Right IEC 61111:2009 Class for Insulation Rubber Mats

1. Determine Your Maximum System Voltage
Start by identifying the highest voltage present in the work area.

• Measure the nominal voltage of live parts (transformers, switchgear, cables).
• Consider any temporary overvoltage or surge potentials (lightning, switching transients).

2. Apply a Safety Margin
IEC 61111 voltage classes are discrete steps. To prevent breakdown under unexpected conditions:

• Pick the next higher class above your system’s maximum voltage.
• For example, if your highest live voltage is 11 kV, choose Class 3 (26.5 kV working voltage).

3. Match to IEC 61111 Class Table
Once you know your system voltage plus margin, use this reference:

IEC 61111:2009 Class	Test Voltage	Working Voltage	Dielectric Strength
0	5 kV	1 000 V	10 kV
1	10 kV	7 500 V	20 kV
2	20 kV	17 000 V	30 kV
3	30 kV	26 500 V	40 kV
4	40 kV	36 000 V	50 kV

4. Account for Environmental and Operational Factors
Beyond voltage, consider how, where, and how often the mats will be used:

• Contamination risk (oil, dust, moisture): choose mats with higher slip-resistance grades.
• Mechanical stress (foot traffic, tool drops): thicker mats offer greater durability.
• Outdoor vs indoor: UV-resistant finishes matter if mats see sunlight.

5. Validate with Risk Assessment
Perform or review a formal risk assessment to confirm:

• All live-working tasks and their voltages are catalogued.
• Possible overvoltage scenarios are covered by the selected class.
• Environmental hazards will not undermine insulation integrity.

6. Implement and Maintain

• Mark or tag mats with their IEC 61111 class so users can verify compatibility at glance.
• Train personnel to match mats to specific jobs and voltages.
• Inspect, clean and retest mats per the standard's intervals to ensure ongoing protection.