Outdoor electrical safety: block heaters, holiday lights and digging

Outdoor wiring in an Edmonton climate

Outdoor receptacles, cords and lights live a hard life here. They freeze, thaw, get buried in snow, soaked by chinook meltwater and baked in summer sun. Cord jackets stiffen and crack in the cold, and water finds its way into anything that is not properly covered.

Most outdoor electrical problems come down to a few things: water getting into receptacles, the wrong cords, overloaded circuits in winter, and accidental contact with buried or overhead lines.

Outdoor receptacles and covers

Outdoor receptacles need GFCI protection, and the code calls for weatherproof covers. For any receptacle that has something plugged in for long stretches, like a block heater or holiday lights, an in-use cover (sometimes called a bubble cover) is the right choice. It closes over the plug so snow and rain stay out.

• Test outdoor GFCIs before winter and again in spring.
• If an outdoor receptacle trips every time it rains or snows, water is probably getting in. Have it checked.
• Replace cracked covers and loose receptacles.
• If you have no outdoor receptacle where you need one, have one added instead of running a cord through a window or door.

Block heaters

A block heater helps your engine start on cold mornings, but it is a real electrical load and it runs in the worst conditions. A few habits make a big difference:

• Use a cord that is outdoor and cold-weather rated, with an amp rating above what your block heater draws.
• Use an outdoor-rated timer so the heater runs for a few hours before you leave, rather than all night. It saves energy and reduces wear.
• Inspect the cord and the car's block heater plug for cracks, bent prongs or scorch marks every fall.
• Do not run the cord where it will be driven over, shovelled or frozen into ice.
• Unplug before you drive away. Many cords and plugs get damaged this way every winter.

If you have more than one vehicle, or a garage with a block heater, space heater and tools on one circuit, overloads are likely. Garage and workshop wiring can add the capacity you need, and if you are thinking about an EV, see our home EV chargers service.

Holiday lights

• Use lights and cords certified for outdoor use in Canada.
• Check each string for broken bulbs, cracked sockets and frayed wires before putting it up.
• Plug into GFCI-protected outdoor receptacles, using in-use covers.
• Do not overload a circuit. LED lights draw far less than old incandescent strings and are easier on your circuits.
• Use plastic clips, not staples or nails, to hang lights.
• Keep ladders and lights well away from the overhead service line to your house.
• Use a timer so lights are not on all night and so they turn off when you are away.

For a permanent solution, many homeowners install landscape lighting or outdoor security lighting with properly wired receptacles at the eaves for seasonal lights.

Hot tubs, pools and yard equipment

Hot tubs are popular in Edmonton backyards, and they combine water, people and a large electrical load. They typically need a dedicated circuit, GFCI protection, a disconnecting means within sight of the tub and proper bonding, all installed under a permit. Clearances from overhead lines and from receptacles also apply.

• Never use extension cords for a hot tub, pool pump or pond pump.
• Have a licensed electrician install the wiring and keep the GFCI tested.
• If anyone feels a tingle in or around the water, get everyone out, switch off the power at the disconnect and call an electrician.
• Store electric lawn and garden tools indoors, and check their cords before each season.

Before you dig

Buried cables are everywhere in Edmonton yards: service cables from the street, lines to detached garages, hot tubs and yard lights. Hitting one with a shovel or post auger can cause serious injury and outages.

1. Request a free locate through Utility Safety Partners (formerly Alberta One-Call) before any digging, even for fence posts, trees or garden beds.
2. Wait until the locates are complete and marked before digging.
3. For private lines, like cable to a garage, shed or hot tub, hire a private locator. The free service only marks lines owned by its member utilities.
4. Hand dig near any marked line.

Common questions