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.

Soluções para testes de isolamento elétrico

Segurança sem compromisso:

Projetados para suportar os ambientes e condições mais adversos, também construímos nossos testadores de resistência de isolamento com a segurança em mente para garantir a proteção dos usuários e dos equipamentos.

Precisão onde é mais importante:

Meça com precisão. Obtenha resultados confiáveis. Repita. Os testadores de isolamento da Megger mantêm a precisão até os altos valores de resistência que muitas aplicações exigem.

Confiabilidade com a qual você pode contar:

Nossas soluções de teste de isolamento elétrico atendem às normas e aos requisitos e superam suas expectativas. Sempre prontos para testar, você se beneficiará da vida útil prolongada dos produtos, o que melhora o ROI do seu programa de gerenciamento de ativos. Mas o mais importante é que você saberá que nossos produtos funcionam quando e onde você precisar deles.

Um parceiro confiável:

A análise de tendências só é eficaz quando os testes são realizados corretamente e os dados são precisos. Os instrumentos da Megger oferecem a precisão necessária para prever e administrar a degradação de ativos. Conte com nossos mais de 130 anos de experiência e conhecimento, obtidos no trabalho em todos os setores da indústria de energia elétrica em todo o mundo, para ajudar você a realizar testes e analisar os resultados da maneira correta.