Insulation is the electrical separation provided between conductive parts, together with the material or arrangement that provides it. You do not usually count it. A cable has insulation. A winding has insulation. You would not say a cable has “three insulations”. An insulator is either a discrete component designed to provide electrical insulation and, often, mechanical support —… Read More: Insulation vs Insulator: What Is the Difference? »
If a material blocks electricity, it probably blocks heat too. It sounds reasonable. It is wrong often enough to matter. Diamond is a wide-band-gap electrical insulator, and it conducts heat better than copper. Graphite felt conducts electricity and is used as high-temperature thermal insulation. Neither is an exotic edge case — together they are a clean demonstration that… Read More: Electrical Insulation vs Thermal Insulation »
An insulator has almost no charge carriers free to move. Apply a voltage and the charges inside it shift slightly but stay bound, so current flow is tiny compared with a conductor. That holds until the electric field gets strong enough, or the material weak enough, to tear carriers loose. Then you get breakdown. That is the mechanism.… Read More: How Does Electrical Insulation Work? »
Take a 400 V motor feeder and strip the cable back to bare copper. Nothing dramatic happens while the conductors stay apart. The air between them is doing the insulating, and dry air under normal atmospheric conditions holds off roughly 3 kV per millimetre. Treat that as a rule of thumb, not a fixed value — it shifts… Read More: What Is the Purpose of Electrical Insulation? »
Insulation testing involves applying high voltage to equipment. The megger on your belt can output 500V, 1,000V, 2,500V, or even 10,000V DC. That’s enough to injure or kill. But the real danger often isn’t the megger itself — it’s the stored energy in the equipment you just tested. A long cable charged to 5,000V DC during a 10-minute… Read More: Safety Procedures for Insulation Testing: A Field Engineer’s Checklist »