That garage power strip isn't protecting anything

Quick answer: A power strip adds outlets and nothing else. A surge protector adds outlets and a part that sacrifices itself to a voltage spike. Put surge protectors on electronics. Plug big motors and heaters straight into the wall.

That white strip with the red switch hanging off your workbench is almost certainly a plain power strip. It runs the shop radio, the battery chargers and a fan. It also feeds a chest freezer, because that's where the outlet ran out. None of it is protected from anything.

What each one actually is

A power strip is a block of outlets on a cord, usually with a resettable breaker. The breaker guards against too much current. It does nothing about too much voltage.

A surge protector has the same outlets plus a component, usually a metal oxide varistor, that soaks up a spike and sends the excess away from your gear. The catch is that it wears out. Each hit uses some of it up.

The box tells you which one you're holding. Look for the words "surge protector" and a UL 1449 listing. If it says "power strip" or "outlet expander," or just says nothing, that's your answer.

Three numbers worth reading

Joules. This is how much energy the unit can absorb before it gives out. Higher is better. A strip rated a few hundred joules is thin protection. For a desk full of computers, look for 1,000 or more.

Voltage protection rating. Under UL 1449, you'll see 330, 400 or 500. Lower is better. It's the voltage the protector lets through when a surge hits. A 330 is the tightest of the three.

The indicator light. Most decent units have a "protected" light. When it goes out, the protection part is spent and you're holding a power strip. Plenty of people use a dead surge protector for years without knowing it.

Rule of thumb: replace them every few years, and right after a nearby lightning strike or a long run of outages, even if the light is still on.

What a surge protector can't do

It won't save your gear from a direct lightning strike. Nothing sold at a hardware store will.

It also only protects what runs through it. Lightning and utility surges often come in through the cable or phone line, not just the outlet. If your modem and router sit on a surge protector with a coax pass-through, use the pass-through. If you skip it, the cable line is a back door. The home internet numbers that matter piece covers what else deserves a minute of your attention at that shelf.

The garage is a different animal

A garage punishes cheap electrical gear. It's cold in January and hot in August. It's dusty and sometimes damp. And the loads are nothing like a living room.

A standard garage circuit is often 15 amps. That's about 1,800 watts at the absolute limit, and roughly 1,440 for anything that runs for hours. A single space heater can pull 1,500 watts by itself. Plug that heater and a compressor into one strip on one circuit and you've built a tripped breaker, or something worse.

Big motors go straight to the wall. Air compressors, table saws, bench grinders, welders, shop vacs. They draw heavy current in a burst when they start. A strip or a standard surge protector isn't built for that kind of load. If you need reach, use a heavy extension cord rated for the tool. For most power tools that means 12 or 14 gauge, and lower numbers mean thicker wire. Check the label on the tool for its amp draw and match the cord to it.

Heaters, never on a strip. Not on a surge protector, not on a power strip, not on a cheap thin cord. They go directly into the wall or onto a cord made for the load.

Don't chain them. A strip plugged into a strip plugged into an outlet is how a workshop fire starts. One strip, one wall outlet.

Know your GFCI. Garage outlets are required by modern code to have ground-fault protection, which is good. It means a wet-floor accident is a trip, not a funeral. It also means a chest freezer or garage fridge can lose power while you're on vacation because the outlet tripped. If that freezer holds a deer, a quarter of a cow, or a season of garden work, put a simple temperature alarm in it. Check the outlet after any storm.

What goes where

Plug into a real surge protector:

• Computers, monitors, printers and anything with a circuit board
• Router and modem, with the cable line run through the pass-through
• A garage TV or stereo
• Battery chargers for cordless tool packs, if you've got several running at once

Plug straight into the wall or a proper heavy cord:

• Compressors, saws, grinders, welders
• Space heaters
• Anything with a big motor that kicks on and off

Plain power strip is fine:

• A work light and a radio
• A phone charger
• Anything small and cheap that you'd shrug off replacing

If you've added smart plugs, check the amp rating on each one before you trust it with a load. The smart home piece is a good starting point for which ones earn their spot.

When one device isn't enough

A plug-in surge protector guards the things plugged into it. A whole-house surge protective device installs at your electrical panel and takes the edge off surges before they reach any outlet. It's not a DIY job. Panels can kill you. Have a licensed electrician look at it, and ask whether it makes sense for your house and your service.

If the garage panel is overloaded, or breakers trip every time you start the compressor, the answer isn't a better strip. It's a licensed electrician and maybe a dedicated circuit. That's a real expense, and also the cheapest fix compared with a fire or a ruined tool.

Twenty minutes this weekend

Walk the garage with a flashlight. Check every strip.

1. Read the label on each one. Does it say surge protector, and is it UL 1449 listed?
2. Find the "protected" light. If it's dark, toss the unit.
3. Pull the heaters and big motors off any strip and plug them into the wall.
4. Look for strips plugged into strips, and fix them.
5. Feel the cords while something's running. Warm is a warning. Hot means stop.
6. Test the GFCI outlets with the test and reset buttons.

The last thing is cheap manners. If you borrow a heavy cord from a neighbor for a weekend project, bring it back coiled, with the plug ends clean. That's the sort of detail people remember. And if you're worried about a data loss from a bad surge on the shop computer, back it up before the next storm, not after.