Can I splice an extension cord?

Splicing an extension cord can seem like a convenient way to extend the length of a cord, repair a damaged cord, or create a custom cord configuration. However, splicing extension cords can be dangerous if not done properly. In this article, we’ll discuss when it is appropriate to splice an extension cord, precautions to take, and how to splice an extension cord safely. We’ll also look at alternatives to splicing that may be safer or more effective for certain situations.

Is It Legal to Splice Extension Cords?

The legality of splicing extension cords depends on where you live and what codes and regulations apply. In general, it is not recommended by electricians, manufacturers or safety agencies to splice extension cords except for certain temporary uses.

The National Electrical Code (NEC) prohibits permanent splices in extension cords unless they are designed with splicing ability and are properly assembled. Any cords sold as temporary or portable types should not be spliced according to the NEC. Local codes may have additional restrictions, so check with an electrician or local permitting office before splicing a cord.

Even if legal, splicing extension cords is not considered safe practice in most cases. The joints can loosen over time, creating a potential fire hazard. Splicing also bypasses safety features like strain relief and creates more opportunities for shorts, sparks and shocks.

When Is It Okay to Splice an Extension Cord?

There are a few scenarios where splicing an extension cord may be acceptable:

– Temporary need – If you need a longer cord for a short-term project, splicing may work. Be sure to inspect the joint frequently and unwind when done.

– Emergency repair – Splicing can temporarily fix a cut or damaged cord until a replacement is available. Rewire properly as soon as possible.

– Designed for splicing – Some extension cords have junction boxes to safely accommodate splicing. Follow all included instructions.

– Permanent installation – If wiring a longer cord into a home electrical system, splicing may be allowed if done properly to code. Consult an electrician.

In general, splicing is only acceptable for temporary or emergency repairs. Any permanent or long-term applications should use a single, continuous extension cord of the proper length.

Dangers of Splicing Extension Cords

Splicing extension cords comes with several risks:

– Loose connections – The joint may loosen over time, increasing resistance and heating. This can start fires.

– Exposed wires – Stripping insulation leaves bare wires exposed. These can cause shocks and shorts.

– Lack of strain relief – Splices may pull loose since they lack protective strain relief found on cords.

– Overheating – Extra connections add resistance which generates heat that can melt wire insulation.

– Fire hazard – All of the above risks increase the chances of fires starting from splices.

– Shock hazard – Exposed wires raise the risks of electrocution or shocks.

– Equipment damage – Excess heat can damage tools, appliances and other equipment plugged into a spliced cord.

Splices also bypass any circuit protection built into the cord, overloading and overheating the wires. For these reasons, splicing should be avoided unless absolutely necessary and performed properly.

How to Splice an Extension Cord

If splicing an extension cord is unavoidable, follow these precautions:

– Use heavy 12-14 gauge cord – Larger wire gauge handles more current and generates less heat.

– Select an indoor/outdoor cord – Look for “SJTW” printed on the cord jacket. Outdoor cords resist moisture and abrasion.

– Choose shorter lengths – Don’t exceed 25 feet total to prevent voltage drop.

– Inspect wires – Replace any cords with cracked, exposed or heat-damaged wiring.

– Remove insulation – Carefully strip 1/2” of insulation off using wire strippers. Avoid nicking conductors.

– Match wire colors – Align ends so hot/live wires join to hot wires, neutral to neutral, ground to ground.

– Use wire nuts – Twist nut over end of wires to fully cover stripped portion. Tug firmly to ensure tight connection.

– Tape splices – Wrap electrical tape around each nut and wires to help hold connection together.

– Relieve strain – Tie a knot in the cord just past the splice to reduce pull on the stripped wires.

– Test splice – Plug in to verify the connection is working before putting into use. Check periodically.

– Consider alternatives – Review other extension options that don’t require splicing.

How to Splice an Extension Cord Using a Junction Box

For a safer, more permanent splice, use a junction box:

– Choose a junction box – Select an outdoor-rated, weather-resistant junction box with strain relief clamps.

– Run cords through clamps – Feed each cord through a separate cable clamp on the junction box.

– Strip wires – Remove 1/2” insulation from each conductor. Take care not to nick wires.

– Connect matching wires – Use twist-on wire connectors to join like-colored wires from each cord.

– Install junction box – Close box and secure tightly with screws or clamps. Ensure a tight seal.

– Relieve strain – Tie knots in each cord just past the clamps. This will prevent pull on the connections.

– Test circuit – Restore power and test that the outlet at the end of the spliced cord is energized.

– Consider upgrading – Have an electrician install new, longer wiring if this will be a permanent need.

Junction boxes create secure, enclosed splices. Follow the manufacturer’s instructions to ensure a safe, lasting connection.

Alternatives to Splicing Extension Cords

Instead of splicing short cords, consider these safer options:

Use a longer continuous cord – Buy a singe extension cord in the required length rather than joining multiple cords. Less connections means less resistance and heat.

Connect cords with a coupler – Special extension cord couplers join two cords safely. Look for heavy duty outdoor-rated couplers.

Buy an extension cord reel – A retractable cord reel keeps the coiled portion off the ground for safety. Cord length can easily be customized.

Install new wiring and outlets – For permanent needs, hire an electrician to add properly installed outlets and circuit wiring.

Use a power strip – Plug a power strip into the outlet to split into multiple receptacles for more devices.

Incorporate shorter jump cords – Use short jumper cords to cover short distances between outlet and device.

Best Practices for Extension Cords

Here are some general guidelines for safely using extension cords:

– Inspect cords thoroughly before each use and discard any damaged cords – look for damaged insulation, exposed wires, loose plugs, frays, cuts, burns.

– Match the amperage rating on the cord to the amp draw of the device being plugged in. Overloaded cords can overheat. Use heavier gauge cords for high draw appliances.

– Unroll cords completely when in use – coils generate excess heat.

– Position cords safely – do not run under carpets or across doorways where they can be damaged.

– Never overload outlets with too many devices. Use properly grounded wall outlets.

– Avoid permanent use – extension cords are designed for temporary, portable applications. Have additional wiring installed for permanent needs.

– Unplug cords when not in use – avoid tripping hazards and accidental shocks.

– Do not link multiple extension cords together. Use a single cord of the proper length.

– Use cords with safety features like circuit breakers, GFCI outlets and strain relief.

– Read and follow manufacturer guidelines and warnings for safe usage.

Conclusion

Splicing extension cords is generally not recommended and comes with significant electrical hazards. For temporary needs, it may be acceptable to splice cords very cautiously using proper precautions. However, hiring an electrician to install new wiring is the best solution for permanent power needs. Carefully inspect all extension cords prior to each use and follow safety guidelines to prevent shocks, fires or equipment damage. With safe usage practices, extension cords can be a useful temporary power solution.