The ohm law to understand the insulation fault of an electrical circuit: - Extra Know
Insulation fault in the electrical installation: explanation and measurement.
Recently, I spoke about ohm's law: this law gives the relation between tension, current and resistance. The theory is one thing, the practice another: Fortunately, there is a direct link between theory and practice, which is often not taught in school. I will explain to you here why the ohm law is useful to understand the insulation fault of a circuit of the electrical installation.

The ohm law to understand the insulation fault of an electrical circuit:

If you've read my article about ohm's law you probably understand, infinite resistance leads to zero current. Here is the explanation by asking the calculation (I add that in mathematics, the division of a number by infinity gives a null result)
An electrically isolated circuit therefore has infinite resistance to current flow. Technically, infinite resistance can be materialized by a distance between two conductive materials that are not connected.

When this resistance decreases, the passage of the current is authorized, and the isolation is broken: it is called continuity, the opposite of isolation. If there is continuity, then there is an insulation fault.

To measure an insulation fault on an electrical circuit, it is enough to measure the resistance between two points of this circuit: If this resistance is infinite, there is total isolation, otherwise, there is an insulation fault.

## Measure the insulation fault with a measuring device:

The equipment to measure the insulation fault

In this example, I use two multimeters, one of first price (left on the image), the other of professional quality, the one I use every day, the model Fluke T5-600.