Appliances You Should Never Plug Into an Extension Cord

Electrical Technology

List of Electrical Appliances You Should Never Plug Into an Extension Cord

Table of Contents

What is an Extension Cord?

An extension cord is a flexible, insulated cable with a plug on one end and one or more outlets on the other. It allows electrical devices to be powered from a source farther away than their standard cord permits. Extension cords are commonly used for temporary wiring needs but must comply with safety standards to avoid hazards like overheating, fire, or electrocution.

Good to Know: An extension cord (commonly used term in the US) is also known as an extension cable, drop cord, power extender, or extension lead (commonly used term in the UK).

Related Post: Why Avoid Plugging Space Heaters into Power Strips or Extensions?

Standard Regulations for Using Extension Cords

According to NEC (National Electrical Code – USA):

In the United States, domestic voltage is typically 120 V. According to the NEC, extension cords used on a 20 A circuit must have a wire size of 16 AWG or larger, such as 14 AWG or 12 AWG, to ensure safe operation and prevent overheating.
Flexible cables and cords must be protected by overcurrent protection mentioned in 240.5(A) or (B).
Flexible cords like extension cords are not a substitute for permanent wiring. They must not be run through walls, ceilings, floors, or doorways. NEC Article 400.
The cord rating must match the load of the connected devices and must include grounding conductors if used with grounded devices.
Extension cords must be UL-listed and for temporary use only and not intended for long-term or permanent installations to ensure they meet safety standards.

According IEC (International Electrotechnical Commission – Global Standards):

Define the construction and insulation requirements for cords IEC 60227 (PVC-Insulated Cables) and IEC 60245 (Rubber-Insulated Cables).
Must adhere to regional standards for compatibility and safety with plug and socket standards.
Extension cords must display markings and specifications with ratings, such as voltage, current, and certification marks, ensuring safe operation.

According to the UK Standards (BS 1363 & 7671):

The cable and fuse ratings should be matched i.e. cords must match the required current capacity, typically 13A for household use. Additionally, plugs must include a fuse for additional safety.
Cords should include a Residual Current Device (RCD) for outdoor or high-risk applications.
Extension cords must not replace permanent wiring and should not be daisy-chained (connecting multiple extension cords together). Excessive length of extension lead can lead to voltage drops or overheating.

Which Electrical Appliances Should Never Be Plugged Into an Extension Cord?

Using extension cords improperly can pose serious safety risks, such as overheating, electrical fires, and equipment damage. Here are some electrical appliances that should never be plugged into an extension cord:

Extension Cords

Plugging one extension cord into another (a practice known as “daisy chaining”) is strongly discouraged. This can cause overheating and circuit shorts, leading to serious electric shock or hazardous fires.

High-Power Appliances

Space Heaters: Draw significant current, which can overheat and overload an extension cord. The Consumer Product Safety Commission estimated that between 2017 and 2019, plugging portable space heaters into power cords were involved in an average of 1,700 fires annually, some of which resulted in fatalities.
Air Conditioners: Require a dedicated circuit due to their high power consumption. Connecting a high wattage AC unit through power strip means inviting a fire hazard to your home.
Refrigerators/Freezers: Continuous high current can damage cords or result in insufficient power supply, affecting performance. Although the wattage rating is not that much high, the continuous operation via extension cord may lead to serious fire hazard.
Microwaves: High wattage may cause overheating of the cord and pose a fire hazard. This heavy-duty appliance should be directly connected to the dedicated circuit.
Air-fryer: Attaching up to 2000-Watts air-fryers to extension cord may lead to fire hazard. If there is no counter space, you may plug into a dedicated wall outlet when needed.
Hair Dryers: Often exceed the safe load of most extension cords.

Kitchen Appliances

Toasters and Toaster Ovens: High current draw during operation. A 1200-1400 Watts toaster draw more power and use high energy whish pose electric fire.
Electric Kettles: Rapid heating requires significant energy.
Blenders or Food Processors (high-powered models): Some models exceed the safe capacity of extension cords.

Medical Equipment

CPAP Machines: A direct and stable power source is critical for safety.
Medical Refrigerators: Used for storing medication or vaccines, they require consistent voltage and current.

Power Tools

Table Saws, Drills, or Air Compressors: These tools can have high startup currents, overloading extension cords.
Welders: Require heavy-duty power sources not suitable for standard extension cords.

Other High-Load Devices

Electric Vehicle Chargers: These require dedicated, grounded circuits to handle the load safely.
Treadmills or Ellipticals: High motor power can overheat cords.

Key Safety Tips:

Check Wattage Ratings: Ensure the extension cord’s rating exceeds the appliance’s wattage requirement.
Use Heavy-Duty Cords: For medium loads, use cords specifically rated for higher amperage.
Limit Daisy-Chaining: Never connect multiple extension cords or power strips together.
Consider Surge Protectors: For sensitive devices like computers, use a surge protector rather than a basic extension cord.
Use Dedicated Outlets: High-power appliances should be connected to their own dedicated circuits.

If unsure, consult the appliance’s manual or an electrician to ensure safe operation.