Understanding A Residential Electrical Plan

Below is an example of the electrical legend found on most of our house plans.

To help you understand these symbols, below is an explanation of each:

 

	= Standard 110 volt wall receptacle. Placement is usually 6 feet apart in the house according to most codes.
	= Standard 220 volt wall receptacle used for major appliances. ie Range, Dryer, Heaters, etc.
	= Ground Fault Interrupt receptacle. Used usually when an receptacle is 6′ or closer to a sink or water source. This type of outlet trips its power off if we ground them out.
	= Standard ceiling mounted light fixture unless it is otherwise noted next to this symbol on the plan.
	= Exterior light fixture, wall or ceiling mounted.
	= Heated & Ventilating Light fixture for bathrooms. Also some homes are equipped with just a Vent light (VL)
	= Recessed light fixture for special lighting in the ceiling. Recessed meaning that it is flush or indented into the ceiling!
	= Exterior lighting or adjustable lamp lighting for the outside of the home.
	= Wall mounted cable television jack.
	= Standard wall mounted light switch. If this were a 3 way switch, (two or more switches for one light fixture there would be a number 3 next to the symbol)
	= Exterior electrical meter mounted to the house. The general rule is to keep the electrical breaker or service box within 12′ of the meter and to mount it in such a way that it is easily accessed by the local utility board personnel.
	= Most fire codes that I know of require that smoke detectors be installed in new homes. Check with your local codes or building inspector for their requirements concerning these.
	= The telephone jack is mounted usually at the same height as the wall receptacles unless it is there for a wall mounted phone, in which case it should be noted on the plan.

Not all Electrical Legends are the same. Below is an example used by another designer, but you’ll notice the similarities.

So lets look at a sample plan. After understanding the symbols, we can pretty well tell what’s going on with the plan.

The electrical part of the plan and the symbols are actually quite easy to understand once we know what they mean.

Look in the Living Room section of the drawing and you’ll see why symbols are used instead of labels.

What’s Here:

• 110 Wall Receptacles
• Light Switches (single and 3 way)
• Dashed Arcs to represent wiring direction
• Light Fixture
• Exterior Light Fixture
• Smoke Detector
• Telephone Jacks
• Cable Television Jack

The image above should help you see more clearly what the electrical is for this part. If the drawing consisted of nothing but labels, there wouldn’t be much room on the drawings for anything else.

In the Bathrooms we see only a few electrical items in the image to the right. One is a light fixture with the letters HVL inside of it in the Main Bathroom. This is a Heat Vent Light that not only lights the bathroom, but adds extra heat to the room and also vents air. The light fixture in the 1/2 half Bath is a bit different as it only has the initials VL inside it. This would be a Vented Light.

Also notice there are 2 wires going to the VL fixture for it’s 2 functions and 3 wires to the HVL. Basically, however many functions there are to the fixture, there is a corresponding broken line arc.

Then if you look at the wall receptacle you’ll see this is a Ground Fault circuit. A Ground Fault Or GFI/GFCI. A GFI is a circuit that will interrupt the electricity if any resistance comes on it, thus preventing someone from being electrocuted should they touch the circuit while they are wet.

On the left, notice the symbol outside of the Utility Room. This is the meter base location. Behind it in the darkened area is the circuit panel. By the note to the left of it we can tell it is a 200 amp service box.

Also notice the GFI circuits at the washer, and around the sink. The general rule is to have a GFI anywhere within 6 feet of a water source if an outlet is needed.

Look at the circle with the letters W.H. This is the water heater. If it is gas, it’s usually noted. If electric, just the circle with initials. Very seldom will the drafter, designer or architect place more than a symbol for a water heater to show wiring for this appliance.

The dishwasher also is usually just the symbol and the GFI receptacle over it is just an outlet in it’s general vicinity. At the dryer and range you see a 220 volt receptacle designated by the circle with three lines.

The rest of the house is standard electrical and can be easily understood if studied.