What Different Types of Math do Electricians Use?

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Electricians need a variety of math skills to do their job on a day-to-day basis. The different types of math an electrician uses in the field are often associated with the specific project they are working on. Therefore an electrician needs to have a variety of math knowledge to make sure, the job gets done correctly.

Electricians use math and calculation to calculate the amount of cable needed for a project, measure distances and make sure that electrical standards are being complied with in general. Electricians also use math to calculate the right dimensions for cables in relation to specific lengths.

Surely an electrician will be provided with an understanding of the basic knowledge of electric circuits, calculations, and methods. Although this is true, only a fraction of the knowledge is being actually applied in the daily life of an electrician.

In this article, you will be provided with an introduction to the most commonly used math and calculations an electrician needs to master the work in their day-to-day life.

What are the Different Types of Math an Electrician Use?

Being an electrician involves many more things than just installing a power outlet or connecting a piece of wire to a ceiling lamp. An electrician also needs to make sure, that the right materials are being used for the right project.

Also read: Is it Hard Work being an Electrician?

When you are being employed by a certified Master electrician, the materials are often being provided for you. This means the right cables have already been picked for you. The thing that an electrician needs to do is to install the cables and materials in the right way. This does require some math skills.

Math used by Electrician’s for Measuring and Calculation

Luckily electricians have a lot of helpful tools that help us get through the task of measuring these things. The most commonly used tools for measuring include:

One of the most common types of math skills an electrician use is in measuring lengths, heights, widths, and depths. Electricians need to know how to measure and calculate the length of wire needed for a specific project.

  • a folding rule (also called a yard-stick)
  • measuring tape
  • 90-degree ruler
  • laser ruler
  • calculator (often times a smartphone calculator is sufficient)

Example 1: Measuring how many cable ties are needed

Measuring tools come in very handy in numerous ways installing electrical equipment. A folding ruler is for example used for installing shorter distances of cable trays. While installing cable trays and placing visible cables on a wall or building, a folding ruler is used to make the right distances between cable ties. A standard, that electricians use is a distance for cable ties is to be around 20 inches or 50 cm. If you have a distance for a cable to run along of say 5 meters, measurement and calculation could simply look like this:

500 cm (distance) / 50cm (distance between cable ties)= 10 cable ties needed for the job (with a distance of 50cm).

Example 2: Finding the length of a cable

Measurement and counting combined with some simple math are also commonly being used when figuring out the length of a cable. Luckily today, cables are being provided with visible numbers, which helps an electrician to know the precise length.

The method is to first get an approximate overview of the length needed by either using a distance ruler with laser or simply by “taking a walk” and counting the steps (most electricians do this). As a general rule, there is 100cm between each step which can then easily be multiplied. So the ridiculously simply equation will look like this:

87 meters cable is needed: 356 meters  (current visible number on cable) – 87 m = 269 m (269 meters being the visible number you will see on the cable to cut off the correct length for the job.

Also read: How to Stay Safe as an Electrician (Avoid Getting Shocked)

Example 3: Find the length of a cable using geometry

An easy way to approximate the length of a cable (with no numbers to do the previous calculation) an electrician can find the length of a cable is to use some simple geometry.

Say we have a bundle of cables, but we want to use 50 meters, an electrician could use a combination of geometry and simple counting.

(1) First measure the diameter between the cable bundle = 50cm

(2) Calculate the circumference with algebra: O (circumference):  50cm diameter * 3.14 (the number of pi) = 157.5cm

(3) Calculate number of circumferences needed: 5000cm (length needed) / 157cm = 31 circumferences of cable needed. This concludes that we need to pick 31 circumferences from the cable bundle to have what we need.

As shown, the math applied by electricians is not in any shape or form spectacular. Although it is not enormously advanced, an electrician needs to be structured and orderly oriented to get the job done right.

Math Theory of the Electrical Trade

Electricians also need to know how to calculate the voltage, ampere, resistance, and watts of an electrical circuit.

The more advanced math in relation to the trade of an electrician is mostly taught at electrical trade school, in order for you to gain knowledge of what goes on behind the scenes in electrical installations. Here you will learn the fundamental of electrical systems. This involves an understanding and an introduction to how to calculate the relation between a volt, ampere, and ohm (also called Ohms Law).

With the law of Ohm, an electrician can quickly calculate unknown values, that one needs to know.

Choosing the correct cable: Electricians use math to calculate what types of cables are needed for certain lengths. For example the longer a distance, a thicker cable needs to be used, in order for having enough power to supply in a power outlet or machine that needs a given amount of ampere.

Choosing correct components: Math is also being used to make sure, that the components in an electrical panel can handle a situation in which a short circuit might happen (when the phase mistakingly connects with a neutral).

The last example of math used by electricians involves a formula or calculation, to make sure, that we don’t exceed the maximum loss of voltage in a given length of cable. In a cable made out of cobber, the loss must not exceed 2 %. As of today, this is the present mathematical calculation for loss of voltage in a cable:

This formula can have different forms, as the content of a cable can exist of mostly either cobber or aluminum. In addition, as electricians and engineers have developed on this over the years, the constants and values of the formula are constantly being updated.

Conclusion on the Mathematics Used by Electricians

If you are someone who is strongly considering a career as an electrician but have previously been struggling with math, in high school or otherwise, you should not see this as an issue.

Everything can be learned, and the methods for developing the skills in math will be gradually learned over the course of your apprenticeship.

Also read: Becoming an Electrician’s Apprentice

The exciting thing about math used by electricians is that we use it in both a theoretical and practical sense. This also provides extra motivation and makes the learning curve a fun experience.