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Power Strip and Surge Protection

A power strip adds outlets. It does not add capacity. A surge protector may help sensitive equipment, but it is not a license to plug in everything.

What is the difference between a power strip and a surge protector?

A basic power strip simply extends one outlet into several. A surge protector adds components intended to absorb some voltage spikes, which can come from storms, utility switching or large motors starting. Packaging can be confusing, so read the label to see what the product claims and which testing mark it carries.

Neither one increases the amount of electricity the wall circuit can safely supply. Everything on the strip still shares one circuit.

Many plug-in surge devices carry a joule or energy rating on the package. Do not rely on a number alone; read the label for the testing mark and the manufacturer's instructions for what the device is meant to protect.

Why is overloading the main danger?

It is easy to plug in a charger, radio, work light, heater and compressor and forget they all share one cord and one breaker. Too much load heats the cord, the strip or the outlet, and the heat may not be visible until something melts or ignites.

Space heaters, compressors, welders and many shop motors are poor candidates for a strip. The appliance manual often says to plug directly into a wall outlet. Follow it.

Where do these devices belong in a shop?

They suit light loads such as chargers, electronics, radios and office equipment, away from dust, moisture and heat. They do not belong on the floor in a wet shop, under piles of paper or behind stacked material, and they should not be chained together.

Keep them mounted or placed where they cannot be stepped on, pinched or sprayed. Dust buildup makes them run hotter, so clean around them.

A tidy cord setup also helps in an emergency. If something goes wrong, you should be able to find and unplug equipment quickly or switch off the circuit without climbing over clutter.

• Plug heavy-draw tools into a wall outlet if the manual says so.
• Do not daisy-chain strips or run a strip from an extension cord.
• Do not use a strip as permanent wiring.
• Replace any strip that is warm, scorched, cracked or loose.

How long does surge protection last?

Many surge protectors wear out after absorbing events, and some have an indicator light that shows when protection is gone. The light behavior varies, so check the manufacturer's instructions. A strip that no longer protects may still pass power, which can give false comfort.

Replace the product as the manufacturer suggests, and after a nearby lightning strike or known power event.

If you are unsure how old your strip is, replace it. A modest replacement cost is far less than losing a tool bench or building.

What protects the whole building?

Local plug-in devices are one layer. Whole-building protection, proper grounding and ground-fault devices are installed by a licensed electrician and depend on the wiring and on local code. If you lose electronics, motors or controllers repeatedly during storms, ask an electrician and your utility what options exist.

The National Weather Service provides storm and lightning safety information. In severe weather, unplugging sensitive equipment, when you can do so safely and before the storm arrives, is another option.

What are the warning signs that a strip is failing?

Warm or hot plug or body, a burning smell, discoloration, crackling, flickering power or a breaker that trips often are all reasons to unplug and stop using it. Investigate the cause rather than just swapping in another strip.

If the strip was part of a bigger pattern of too few outlets, plan to add outlets. That is a better fix than more strips.

Keep a list of what is plugged into each strip and write the circuit it runs on at the panel. This is simple to do and it shows you quickly when a circuit is overloaded.

Is it safe to leave things plugged in overnight?

Leaving a charger or shop radio on a protected strip is common, but unattended heat is the risk. Chargers for batteries, tools and equipment can run warm. Check the manufacturer's instructions, and unplug anything that makes heat or that you would not want to run while nobody is around.

Heaters, welders and compressors should not be left powered and unattended on a strip. If you are not sure, power it down at the end of the day and make the end-of-day shutdown a habit.

Last reviewed: November 12, 2026. Written by the Farm Safety Editorial Team. See our editorial policy.