Insulation Resistance Meter

What is a Megohmmeter?

A megohmmeter is a specialized measuring instrument used to determine insulation resistance in electrical systems. It works by applying a high voltage to the insulation of cables, transformer windings, or other electrical components to assess their ability to withstand stress without breakdown or energy loss.

Key Issues Addressed by a Megohmmeter:

• Insulation degradation or damage over time can lead to short circuits or even fires.

• Regular insulation testing helps prevent accidents caused by electrical failures.

• A megohmmeter helps identify whether the insulation can withstand operating conditions, which in turn helps avoid costly repairs.

How a Megohmmeter Works

The main function of a megohmmeter is to measure resistance between wires, grounded parts, or other conductive components. This helps detect insulation breakdowns. Low resistance indicates flaws in the insulation material, which may result in short circuits or other hazards.

The megohmmeter applies high test voltages to evaluate the insulation's ability to handle voltage spikes in the network. This helps detect potentially dangerous weak points that may cause failures under real-world operating conditions.

Megohmmeters are commonly used to test insulation in windings of electrical machines, such as transformers, revealing internal defects, including insulation breakdowns.

Difference Between a Megohmmeter and an Insulation Tester

A megohmmeter differs from a standard insulation tester by its ability to apply significantly higher test voltages to the system under inspection. This allows for a more realistic assessment of insulation performance, while regular testers typically use lower voltages for basic checks.

How to Use a Megohmmeter to Measure Resistance

Using a megohmmeter to test insulation resistance requires following a clear sequence of steps to ensure accurate results. The basic procedure is as follows:

1. Ensure the system is completely disconnected from any power sources.

2. Connect one lead of the megohmmeter to the cable or winding, and the other lead to ground or a metal part that should not carry current.

3. Select the appropriate test voltage depending on the system (commonly 250 V, 500 V, or 1000 V).

4. The megohmmeter will display the resistance value.

   • High resistance indicates good insulation.

   • Low resistance signals potential issues.

Approximate resistance guidelines:

• Over 1 MΩ – good insulation;

• Less than 1 MΩ or 500 kΩ – poor insulation.

Where to Buy a Megohmmeter in Ukraine

To purchase a reliable and accurate device for measuring insulation resistance, visit our online store at sea-tm.com.ua. We offer a wide range of megohmmeters from leading manufacturers, all compliant with high quality standards.

You’ll find instruments suited for various applications — from basic models for home use to professional-grade devices for large industrial facilities. We provide fast delivery across Ukraine and in-store pickup in Kyiv.