How To Calculate Insulation Resistance Of Cable

Insulation resistance is a critical factor in electrical cable safety and performance. Calculating it helps prevent failures and ensures compliance with safety standards.

1. Enter the voltage, current, and cable length.
2. Click ‘Calculate’.
3. View the result and chart.

The formula for insulation resistance (R) is:

R = V / I

Where:

• V = Voltage (V)
• I = Current (A)

Case Studies

Comparison of Insulation Resistances

Cable Type	Insulation Resistance (MΩ/km)
PVC	500 – 2000

Expert Tips

• Regularly test insulation resistance.
• Use higher insulation resistance for critical applications.

FAQ

What is a good insulation resistance value?

It depends on the application, but generally, higher is better.

For more information, see:

• OSHA’s guide to grounding
• IEEE paper on cable insulation