Air Conditioning

You generally should not plug a window or portable air conditioner into a standard power strip. Air conditioners can draw considerable electricity, especially when the compressor starts. A typical power strip may overheat, trip the circuit breaker or create a fire hazard when used with an appliance that requires more power than the strip can safely handle.

Instead, plug the air conditioner directly into a properly grounded wall outlet that meets the voltage, amperage and circuit requirements listed by the manufacturer.

Appliances that generally should not be connected to an ordinary power strip include:

  • Window and portable air conditioners
  • Space heaters
  • Refrigerators and freezers
  • Microwaves
  • Toasters and toaster ovens

A power strip having enough open outlets does not necessarily mean it can safely power everything connected to it. UL Solutions recommends checking the strip’s electrical rating and the amount of power required by every connected device.

Central air conditioners, heat pumps and most mini-split systems are different from portable and window units. These systems are normally connected to dedicated electrical equipment rather than plugged into an ordinary household outlet.

Why You Should Not Use a Power Strip with an Air Conditioner

The primary reason to avoid using a power strip with an air conditioner is the possibility of overloading the strip or circuit.

Air Conditioners Require a Significant Amount of Electricity

An air conditioner’s compressor and fan motors require more electricity than many of the devices commonly connected to power strips. The compressor can also require an additional burst of electricity when it starts.

Even when the AC seems to operate normally, an undersized strip may gradually become hot as the unit continues running. Overheating can damage the strip, AC plug or wall outlet.

The Consumer Product Safety Commission warns that electrical cords, strips and surge protectors must be capable of handling the current required by the connected appliance. Faulty construction, undersized wires, loose connections and improper grounding can create fire and shock hazards.

A Surge Protector Can Still Be Overloaded

The words “surge protector” do not mean a device has unlimited electrical capacity. Surge protection addresses short increases in voltage. It does not eliminate the possibility of overloading the strip by drawing too much current.

Each strip has a maximum rating, usually listed in amps or watts. That limit applies to the combined demand of everything connected to it.

Connecting an AC and several other devices to the same strip can increase the chance of:

  • Overheating
  • Repeated shutdowns
  • A tripped circuit breaker
  • Melted plastic
  • Damage to electrical connections
  • Fire

Do not connect one power strip to another or plug a strip into an extension cord. This practice, sometimes called daisy-chaining, can further increase the risk of an overload.

The Air Conditioner May Need a Dedicated Circuit

Some air conditioners require a dedicated electrical circuit, meaning the circuit serves the AC rather than several appliances. The requirement depends on factors such as the unit’s voltage, amperage, size and manufacturer instructions.

A dedicated circuit may be especially important for larger window units or portable systems. An outlet that has nothing else plugged into it is not necessarily on a dedicated circuit; other outlets elsewhere in the room may share the same circuit.

Check the air conditioner’s manual and electrical label before installation. An electrician can determine whether the outlet and circuit are appropriate for the unit.

Manufacturer Instructions May Prohibit It

An air conditioner’s installation and operating instructions should be the final authority. Many manufacturers direct homeowners to connect the appliance directly to a grounded outlet and warn against using extension cords, adapters or shared outlets.

Using an unapproved power strip may also affect warranty coverage if the electrical setup contributes to equipment damage.

Additional Air Conditioner Electrical Safety Tips

Whether you have a portable, window or central air conditioner, following a few basic precautions can reduce the risk of electrical damage and equipment problems.

Plug the AC Directly Into the Wall

Connect a portable or window unit directly to a properly grounded wall outlet that matches its voltage and amperage requirements. Do not remove the grounding prong or use an adapter to make a three-prong plug fit a two-prong outlet.

Do Not Use a Standard Extension Cord

Avoid using an ordinary household extension cord with an air conditioner. If the factory-installed cord cannot reach the outlet, reposition the unit or have an appropriate outlet installed.

Do not replace the AC cord, alter its plug or create a homemade extension. Extension cords that lack proper wire size, strain relief, polarity, continuity or other safety characteristics can create fire and electrical-shock risks.

Do Not Share the Outlet With Another Large Appliance

Avoid using the other receptacle for a space heater, refrigerator, microwave, vacuum or another high-demand appliance. Two appliances can overload the circuit even when neither one causes a problem on its own.

Examine the Cord and Outlet

Before operating the AC, check for:

  • Fraying or cracked insulation
  • Bent or discolored plug blades
  • Black marks around the outlet
  • Loose-fitting plugs
  • Melted plastic
  • Exposed wiring
  • Damage to the grounding prong

Stop using the unit when its cord, plug, or outlet appears damaged, or you notice overheating.

Keep Electrical Connections Dry

Do not operate a window or portable AC with wet hands or near an electrical connection exposed to water. Make sure a window installation prevents rainwater from reaching the plug, cord or outlet.

Use Listed and Properly Rated Products

When purchasing an electrical cord, strip or surge-protection device for approved applications, look for certification from a recognized testing laboratory and verify its electrical rating.

Certification does not mean the product is suitable for every appliance. It still must be used according to its listing, rating and manufacturer instructions. UL Solutions recommends checking both the product certification and its amp or watt rating before use.

Schedule an Inspection if the Breaker Keeps Tripping

A breaker that trips once during an unusual electrical event may not indicate a major AC problem. A breaker that trips repeatedly should not be ignored.

When to Call an HVAC Technician

An HVAC technician can inspect the air conditioner for issues such as excessive electrical draw, a failing motor, a damaged capacitor or compressor trouble. Problems involving the outlet, household wiring, breaker or electrical panel may require a licensed electrician.

Contact the experts at BVS Home Experts to evaluate the air conditioner and help determine whether the repeated shutdown is being caused by the cooling equipment or the electrical supply.

Related HVAC Guides

Frequently Asked Questions

Can You Plug a Portable Air Conditioner Into a Power Strip?
A portable air conditioner generally should be plugged directly into a properly grounded wall outlet rather than a standard power strip. Follow the unit manufacturer’s voltage, amperage, and circuit requirements.
Can You Plug a Window Air Conditioner Into a Surge Protector?
Do not assume that a plug-in surge protector is suitable for a window air conditioner. Most window AC units should be connected directly to an approved wall outlet unless the manufacturer explicitly allows another arrangement.
Is a Power Strip With a Circuit Breaker Safe for an Air Conditioner?
A built-in circuit breaker does not automatically make a power strip safe for an AC. The strip can still be inappropriate for the appliance’s electrical demand, and the manufacturer may require a direct wall connection.
Can You Use an Extension Cord With an Air Conditioner?
The safest option is to avoid using an extension cord. Reposition the AC or have a suitable outlet installed closer to the unit. Never use a lightweight household extension cord or connect multiple cords together.
Does a Portable Air Conditioner Need a Dedicated Circuit?
Some portable air conditioners require a dedicated circuit, while smaller units may be permitted on an appropriately sized circuit that serves other outlets. Check the manufacturer’s instructions and have the circuit evaluated if you are uncertain.
Why Does My Air Conditioner Keep Tripping the Breaker?
Repeated breaker trips may be caused by an overloaded circuit, a damaged outlet, wiring trouble, or an air conditioner component drawing too much electricity. Stop repeatedly resetting the breaker and arrange for an inspection.
Can a Window AC Share an Outlet With Another Appliance?
Avoid connecting another high-power appliance to the same outlet. Even when both devices appear to operate, their combined demand may overload the circuit.
Are Power Strips and Surge Protectors the Same?
No. A basic power strip adds outlets but may offer no protection against voltage surges. A surge protector contains components intended to limit excess voltage. Neither product should be used with an air conditioner unless it is specifically approved for that application.
How Can I Protect My Central Air Conditioner From Power Surges?
Central AC systems can be protected with professionally installed HVAC or whole-home surge-protection equipment. Because central systems are not plugged into ordinary household outlets, a standard consumer power strip is not an appropriate solution.
When Should I Call BVS Home Experts?
Contact BVS Home Experts when your air conditioner repeatedly trips the breaker, shuts down during startup, makes unusual electrical noises, or appears to be drawing excessive power. Stop using the system immediately if you notice smoke, sparks, burning odors, or overheated electrical components.

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