Wiring Diagrams and symbols

Understanding wiring diagrams and symbols…

is one of the first steps in becoming an electrician.You will need to know how to read and understand wiring diagrams and symbol in any path of electrical field work.

Electrical estimators of course need to know how to read and interpret blueprints,schematic and wiring diagrams to give an accurate bid in order to keep electricians working.

Electricians both residential and commercial need to interpret what the architect and engineer have in mind for the proper outcome from their design.

Electrical service technicians may not need to understand a complete set of drawings when doing their job but they do need to understand how to read schematics and symbols.

In the picture¬† you will see what the abbreviations mean on a set of electrical plans. These are somewhat standard across the industry but some E.E.’s will add a few of their own.

Just because a set of plans don’t show all abbreviations doesn’t mean they won’t exist on your plans.So look over the prints and be sure to ask if there is some abbreviation you don’t see or understand.

Also keep in mind that the other trades have their abbreviations as well and you will need to get to know them too.




The Index of Drawings.

will tell you how many pages are within a set of drawings for a particular project.

Get to know these well,there is so much information to complete your project.

Device symbols are the symbols used to show you where and what type of device is require. Generally they will show the amperage and other specification you’ll need to install the electrical wiring in your project.

Like the other symbol sheets they may not contain all the required information.

Panel symbols will show various details you need for work that will be completed at or around your panel. Look at these closely and check that they apply to your project. Just because it shows a photo cell doesn’t mean you need on. Most E.E’s use a¬† standard template in their drawings.

Fire Alarm Symbols are shown on the electrical drawings for a couple of reasons. One being electrical contractors are required to install the complete fire alarm system so you’ll need to know where to install the devices.

Two would be that a fire alarm contractor will come in and install the free wiring and devices leaving the boxes for the electrical contractor. It all varies from project to project.

In another post I started discussing electrical estimating and I belive a good estimator will be a master at reading wiring diagrams and understanding symbols.

Get to know these symbols,your future depends on it.

In a future post I’ll show you more of the other trades symbols and “how to read” electrical drawings and complete sets of plans.


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