EZSMART Corporation, ESA/ECRA #7012690 , North York , Ontario
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Open a receptacle box in a well-wired Toronto or GTA home and you will often see three or more conductors joined together with a wire nut, plus one short wire coming off the joint to the outlet’s screw terminal. That short wire is a pigtail, and it is one of the small details that separates good wiring from marginal wiring. This guide covers what a pigtail is, why professionals use them, when Ontario code effectively requires them, and how they are done correctly.
A pigtail is a short length of conductor (typically 6 to 8 inches) that connects multiple wires together with a wire nut and then lands the joint on a single device terminal. Instead of daisy-chaining an outlet’s line and load through the receptacle body, a pigtail keeps the circuit continuous through the wire nut and uses the receptacle only as a tap. The result is that removing or replacing the device does not interrupt power to anything downstream, and the device itself is not carrying pass-through current.
Daisy chain (through-the-device wiring): incoming hot lands on one screw terminal of the outlet, outgoing hot lands on the other. All downstream circuit current flows across the receptacle’s internal metal strap. If that strap or terminal fails, downstream outlets lose power.
Pigtail: incoming hot, outgoing hot, and the pigtail meet inside the box under a wire nut. The pigtail alone lands on the outlet’s screw terminal. Removing the outlet does not interrupt the downstream circuit, and the outlet is not carrying pass-through current.
Both methods can pass an inspection in most cases, but pigtailing is the pro standard for good reason.
The Ontario Electrical Safety Code and the underlying Canadian Electrical Code do not always mandate the specific word “pigtail,” but there are code-driven situations where pigtailing is the only practical way to meet the rule:
Wire nuts are inexpensive but must be sized and installed correctly to be reliable. See how to properly tighten screw terminals on outlets for the device side.
Homes with aluminum branch circuits (typically 1965–1975 Ontario builds) frequently have devices remediated by pigtailing the aluminum conductor to a short copper pigtail, then landing the copper on the device. The industry-standard listed connector for this is AlumiConn (a set-screw connector with anti-oxidant compound). Wire nuts marketed for aluminum-to-copper have a mixed reputation and are best avoided in favour of listed connectors.
Full context at is aluminum wiring dangerous in a house.
In many situations, no — daisy-chain wiring through a device is legal on a straightforward single-cable-in, single-cable-out setup. In the situations listed earlier (MWBCs, multiple conductors, aluminum, ground continuity), pigtailing is either required or the only clean way to comply.
Even where not required, pigtailing is generally the mark of quality installation and is what most licensed contractors will default to. If you are hiring, ask the contractor what their standard is.
In our GTA field data, the single most common outlet failure in a home built after 1975 is a backstabbed daisy-chain that has loosened at the receptacle. The fix is almost always to remove the backstab, add a pigtail with a wire nut, and land the pigtail on the screw terminal. If we could get every homeowner to insist on pigtail-and-screw wiring at every device in every reno, we would replace far fewer burnt receptacles. If you are having any outlet work done, ask the electrician whether they pigtail. “We always pigtail” is the answer you want to hear.
Not always, but it is required whenever a shared neutral must remain continuous or when more conductors need to join than a device terminal can hold.
Yes. Wire nuts and pigtail conductors count toward box fill capacity under the OESC.
Yes. Ground continuity through the box requires pigtailing when multiple grounds are present.
Yes. Wire nuts and lever connectors both meet the pigtail requirement when listed for the application.
Standard remediation is to pigtail aluminum to copper with a listed AlumiConn connector at every device.
Have failing outlets in your Toronto or GTA home that need re-pigtailed to the screw terminals? Call ezsmart at 416-838-9006 or use our contact page. An ESA-licensed electrician will redo devices to the pro standard.
Electrician Since 2008 Journeyman Electrician Designated Master Electrician at EZSMART Corp
