Electrical insulation testing solutions

The leading portfolio for installation and power assets, from Megger

When the world’s leading electrical experts need the tools to get the job done right, they go with Megger. That’s because as the industry experts, we design our insulation testers to address every critical challenge that may arise, throughout the complete lifecycle of the asset. From commissioning and installation to transportation and repairs, you can trust our in-depth knowledge and top-of-the-line products to empower your decision-making.

Talk to an expert

All Electrical insulation testing AC insulation testing DC insulation testing DC withstand testing Insulating oil testing Insulation resistance testing < 1 kV VLF insulation testing

Safety without compromise:

Designed to endure the harshest environments and conditions, we also build our insulation resistance testers with safety in mind to ensure the protection of both users and equipment.

Accuracy where it matters:

Measure with precision. Get confident results. Repeat. Megger’s insulation testers maintain accuracy up to the high resistance values many applications demand.

Reliability you can depend on:

Our electrical insulation testing solutions meet regulations and requirements, and exceed your expectations. Always ready to test, you’ll benefit from extended product lifespans that improve your asset management program’s ROI. But most importantly, you’ll know that our products work whenever and wherever you need them to.

A trusted partner:

Trend analysis is only effective when tests are performed properly and the data is accurate. Megger's instruments provide the precision you need to predict and manage degradation of assets. Leverage our 130+ years of expertise and knowledge, gained from working across all sectors of
the electrical power industry around the world, to help you conduct tests and analyse results the right way.

How often should you do insulation tests?

That depends upon the size, complexity, and criticality of your equipment. Even identical units can differ in the required check periods; experience is your best guide. In general, however, working apparatus – such as motors and generators – are more likely to develop insulation weaknesses than wiring, insulators, and the like. A test schedule for working equipment should be established, varying from every 6 to 12 months, depending on the size of the equipment and the severity of the surrounding atmospheric conditions. For wiring and the like, tests once a year are generally sufficient unless the installation conditions are unusually severe.

Does the CAT rating matter for an insulation test, as it's designed to be used only for dead circuit testing?

The answer, at least in part, is in the question! An insulation resistance tester is designed to be used only on dead circuits, but that’s no guarantee that it won’t ever be accidentally connected to a live circuit. And if it is, an appropriate CAT rating is essential, especially as the environments in which HV insulation testers are most frequently used often have high supply transients. We recommend a CAT IV 600 V rating, and it’s imperative to be sure that this rating applies to all of the instrument’s terminals, including the guard terminal.

Why choose an insulation test that offers a high output current as a preference to one with a lower output current?

There are several reasons to select a test set with a high output current. Possibly the most important is that a high output current means that the item under test will be charged more quickly, which means that the test can be completed in a shorter time and also that there’s less risk that the readings will be taken before the test voltage has had time to stabilise properly. And, if you’re using the instrument’s guard terminal, don’t forget that a lot of output current may well be diverted via the surface leakage of the item under test. Unless the instrument has a high output current capability, this could mean that the output voltage will collapse, and the test results will not be valid.

Which DC insulation tester do I need?

First, decide on the type of testing you need to perform. If it’s routine go/no-go testing and you don’t need data storage, an Essential instrument (MIT515) will likely be a cost-effective choice. Consider an Advanced instrument (MIT525, MIT1025, MIT1525) for more versatility and/or internal data storage. And if working in extremely electrically noisy environments or need high charge/burn currents, an Expert instrument (S1-568, S1-1068, S1-1568) will be right. Having decided on Essential, Advanced or Expert, choose the instrument that will deliver the maximum test voltage needed.

Find Out More

Can’t find what you’re looking for? Whether you require simple instruments or advanced features, contact us to speak with an expert about your unique needs.