How to label your electrical panel

Why a good directory matters

When a receptacle stops working, a pipe heat tape fails on a cold night or you need to shut off a circuit for a contractor, the panel directory is the first thing you reach for. In many older Edmonton homes it says little more than "plugs" and "lights" in faded pencil, or it was never updated after a basement development.

Mapping your panel is one of the few electrical jobs a homeowner can safely do, because it only involves switching breakers on and off with the door open. It takes an afternoon and pays off for years.

Before you start

• Pick a daytime slot so you have natural light, and warn the household that power will go on and off.
• Protect what should not lose power. Save work on computers, and know which breaker feeds the furnace, sump pump, freezer and any medical equipment. Turn those back on promptly.
• Gather supplies: a helper with a phone, a plug-in lamp or receptacle tester, masking tape, a pencil and a rough floor plan of each level.
• Find the flashlight. You will be switching off the circuit you are standing in sooner or later.

Map the circuits

1. Draw a simple floor plan of each level and mark every receptacle, light, switch and hard-wired appliance.
2. Turn on all the lights and plug your lamp or tester into the first receptacle.
3. At the panel, switch off one breaker and say its number.
4. Your helper checks each room and reports what went dead. Write that breaker number beside every device on the plan.
5. Turn the breaker back on before moving to the next one.
6. Check both halves of each receptacle; sometimes the top and bottom are on different circuits.
7. Repeat until every breaker is accounted for, including 240 V ones for the range, dryer and water heater.

Write a directory that helps

Once the map is done, rewrite the directory on the panel door. Good entries are specific and short:

• Name the room and the location: "Kitchen counter right of range" rather than "Kitchen".
• Name key appliances: furnace, fridge, freezer, sump pump, garage door opener, block heater receptacle.
• Mark circuits that must stay on: "Furnace: do not switch off in winter".
• Note both numbers for double-pole breakers: "7-9 Dryer".
• Mark empty spaces as "Spare".
• Date it, and keep the floor-plan map in a sleeve inside the panel door or with your house records.

Write the directory for someone who has never been in your house: a house sitter, a new owner or an electrician arriving at night. If they can find the furnace breaker in ten seconds with a flashlight, it is doing its job.

Things you might discover

Mapping often turns up surprises. Make a note of any of these for your electrician:

• A breaker that seems to control nothing. It may feed something outdoors, in the attic or behind a wall.
• A receptacle or light that stays on with every breaker off. That can mean a second panel or a wiring problem.
• One breaker feeding a huge part of the house, which can explain why breakers trip.
• Receptacles in bathrooms, kitchens or outdoors that do not shut off with the breaker you expect because they are downstream of a GFCI. See GFCI and AFCI protection.
• Too few spare spaces for your plans. See when your panel is full.

Once your directory is done, update it whenever anything changes: a new circuit for a basement bedroom, a hot tub, or a breaker swapped during a repair. An out-of-date directory can be worse than none, because people trust it.

Electricians are required to identify the circuits they install, and Alberta Electrical labels every circuit we touch. If your panel needs more than a label, a home electrical inspection is a good next step.

Common questions