Can You Plug Two Extension Cords Into The Same Outlet? Safety Considerations
Plugging two extension cords into the same outlet is generally not recommended due to the risk of overloading the circuit and creating a fire hazard; however, carefully considering the total wattage of the connected devices is crucial to avoid danger.
Understanding Electrical Circuits: A Primer
Before diving into the specifics of extension cords, it’s essential to understand the fundamentals of electrical circuits. Your home’s electrical system is designed to deliver a specific amount of power. Each circuit, protected by a circuit breaker, has a maximum amperage (amps) rating, typically 15 or 20 amps. Voltage in US residences is usually 120V. Wattage is the measure of electrical power used, calculated by multiplying amps by volts (Watts = Amps x Volts). Overloading a circuit occurs when the total wattage drawn by connected devices exceeds the circuit’s capacity.
Why Piggybacking Extension Cords Can Be Risky
Can you plug two extension cords into the same outlet? While technically possible, doing so can quickly lead to problems. The primary risk is overloading the circuit. When multiple devices draw power through a single outlet (even if spread across multiple extension cords), the risk of exceeding the circuit’s ampacity significantly increases. This can cause the circuit breaker to trip, shutting off power, but more dangerously, it can lead to overheating of the wires, potentially causing a fire.
Calculating Wattage and Amperage
Before even considering daisy-chaining extension cords, you must calculate the total wattage of all devices that will be plugged into both cords. Most devices have a wattage rating printed on a label or embossed on the product itself. Add up the wattage of each device.
Then, calculate the total amperage. If the wattage is known, divide the wattage by the voltage (120V in most US homes): Amps = Watts / Volts. Compare the total amperage to the circuit breaker’s rating. Do not exceed 80% of the circuit breaker’s rating. This leaves a safety margin to account for fluctuations and prevents nuisance tripping.
For example:
- A 15-amp circuit can safely handle: 15 amps x 120 volts x 0.8 = 1440 watts.
- A 20-amp circuit can safely handle: 20 amps x 120 volts x 0.8 = 1920 watts.
Safer Alternatives to Daisy-Chaining Extension Cords
Instead of connecting extension cords together, explore safer alternatives:
- Use a power strip with surge protection: Power strips allow you to plug in multiple devices at a single outlet while offering overload protection. Look for models with a built-in circuit breaker.
- Install additional outlets: If you frequently need more outlets, consider hiring an electrician to install additional outlets on a separate circuit. This is the safest and most permanent solution.
- Use a longer, heavier-duty extension cord: Instead of combining two shorter cords, use a single, longer extension cord that can reach the desired location. Choose a cord with a gauge appropriate for the load.
Common Mistakes and How to Avoid Them
- Ignoring the wattage rating: Many people simply plug in devices without considering the power requirements. Always check the wattage rating and calculate the total load.
- Using undersized extension cords: Using a lightweight extension cord for high-power devices can cause the cord to overheat. Use a heavier-gauge cord for appliances like space heaters and power tools. The lower the gauge number, the thicker the wire and the more current it can safely handle.
- Overloading the outlet: Even if you don’t daisy-chain extension cords, plugging too many devices into a single outlet (or power strip) can overload the circuit.
- Using damaged cords: Inspect extension cords regularly for damage, such as frayed wires or cracked insulation. Discard damaged cords immediately.
Extension Cord Gauge: Understanding the Importance
The gauge of an extension cord, typically indicated by the American Wire Gauge (AWG) number, dictates the amount of current the cord can safely carry. A lower AWG number indicates a thicker wire, capable of handling more amperage. Using a cord with an insufficient gauge can lead to overheating and fire hazards.
Here’s a general guideline:
| AWG Gauge | Maximum Amperage | Typical Use |
|---|---|---|
| 16 | 13 | Light-duty appliances, lamps |
| 14 | 15 | Small appliances, power tools |
| 12 | 20 | Heavier-duty power tools, appliances |
| 10 | 25 | High-power equipment, construction tools |
Always choose an extension cord with a gauge appropriate for the load you intend to connect.
Extension Cords: Temporary Solutions Only
Extension cords are intended for temporary use only. If you find yourself relying on extension cords frequently, it’s a sign that you need more permanent electrical solutions, such as installing additional outlets.
Frequently Asked Questions (FAQs)
Can I plug a power strip into an extension cord?
While sometimes unavoidable, plugging a power strip into an extension cord introduces another point of potential failure and should be avoided if possible. Instead, opt for a power strip with a longer cord or consider relocating the power strip closer to the outlet. If you must use an extension cord, ensure it’s a heavy-duty cord and that the total load on the power strip doesn’t exceed the cord’s rating.
What happens if I overload a circuit?
Overloading a circuit will typically cause the circuit breaker to trip, cutting off power to the circuit. This is a safety mechanism designed to prevent overheating and fires. However, repeated tripping of the circuit breaker is a sign of a more serious problem, and you should investigate the cause and reduce the load. If the breaker fails to trip, the wires can overheat, potentially leading to a fire.
Is it safe to cover an extension cord with a rug or carpet?
No, covering an extension cord with a rug or carpet can trap heat and potentially cause the cord to overheat. Always keep extension cords uncovered and well-ventilated.
What is the difference between a surge protector and a power strip?
A power strip simply provides multiple outlets from a single outlet. A surge protector, on the other hand, is designed to protect connected devices from voltage spikes. Look for power strips with surge protection for added safety.
How do I know if an extension cord is rated for outdoor use?
Outdoor extension cords are specifically designed to withstand the elements. They are typically made with heavier-duty insulation and are labeled as “suitable for outdoor use.”
Can I use an extension cord with a damaged plug?
No, a damaged plug can be a serious fire hazard. Never use an extension cord with a cracked, broken, or loose plug. Replace the cord immediately.
Are all extension cords created equal?
No. The quality of materials and construction vary significantly between different brands and models. Cheaper cords may use thinner wires and less durable insulation, increasing the risk of overheating. Invest in high-quality extension cords from reputable manufacturers.
How often should I inspect my extension cords?
Inspect your extension cords regularly, at least once a month, for signs of damage, such as frayed wires, cracked insulation, or loose plugs.
What does “grounded” mean in relation to extension cords?
A grounded extension cord has three prongs, including a grounding prong. This prong provides a path for electricity to safely flow to the ground in the event of a short circuit, reducing the risk of electric shock. Always use grounded extension cords with grounded outlets.
Can I run an extension cord under a doorway?
Running an extension cord under a doorway can damage the cord and create a tripping hazard. Avoid doing this whenever possible. If you must, use a cord cover to protect the cord and prevent tripping.
What is the maximum length an extension cord can be?
While there’s no official maximum length, it’s generally recommended to keep extension cords as short as possible to minimize voltage drop and the risk of overheating. For high-power applications, use a shorter, heavier-gauge cord.
Can you plug two extension cords into the same outlet if they are only powering low-wattage devices like lamps?
Even with low-wattage devices, can you plug two extension cords into the same outlet? The answer is still “proceed with caution.” While the risk is lower, it’s crucial to calculate the total wattage of all devices connected to both cords. Even low-wattage devices can collectively exceed the circuit’s capacity, especially on older wiring.