What Is a Pigtail in Electrical Wiring?

What Is a Pigtail in Electrical Wiring?

A pigtail is a short wire added to a connection to allow multiple conductors to share a single terminal or to reduce the number of conductors spliced directly onto a device. The pigtail itself connects to the device’s terminal while the other end of the pigtail joins the circuit conductors with a wire nut inside the box. This technique is widely used when there are more wires at a device than the device terminals can safely accommodate.

When Pigtails Are Required or Preferred

• Receptacles and switches are rated for one conductor per terminal — if two or more wires must connect at the same terminal (a “home run” and a “feed-through”), a pigtail joins all wires in the box with a nut, and a single short pigtail connects to the device terminal
• Aluminum wiring: aluminum conductors must be pigtailed with copper using AL/CU-rated connectors and anti-oxidant compound before connecting to standard devices — devices must also be AL/CU rated or the pigtail eliminates the direct aluminum-to-device contact
• When replacing a 2-wire ungrounded outlet in an older home, a pigtail from a GFCI outlet’s LINE terminals feeds all downstream boxes, so only one GFCI outlet is needed to protect multiple locations
• In junction boxes where multiple circuits meet, pigtails keep each device connection to a single conductor for cleaner, safer terminations

Pigtail Length and Gauge

Pigtails must be the same gauge as the circuit conductors — a 12 AWG circuit requires 12 AWG pigtails; a 14 AWG circuit uses 14 AWG pigtails. The minimum length is enough to work comfortably outside the box — typically 15-20cm. The pigtail should be the same colour as the conductor it represents (black for hot, white for neutral, green or bare for ground). EZSMART electricians follow all code requirements for device connections and pigtailing. Contact us for any wiring or renovation project across Ontario.

Amir Azimipour

Electrician Since 2008 Journeyman Electrician Designated Master Electrician at EZSMART Corp