Using an extension cord, safe?

March 12, 2006 8:56 AM

Safe to use an extension cord for a small refrigerator?

The instructions for a small (1.7 CF) refrigerator tell me not to use an extension cord but to have the unit rewired with a longer cord. That seems a major expense and exercise. To reach the plug (three more feet) I purchased an air conditioner extension cord on the theory that air conditioners draw a lot of electricity so it should be safe for this little refigerator.

Is using an extension cord with this small refrigerator safe? Thanks

posted by KneeDeep to technology (15 answers total)

Most likely you'll be fine. Get the heaviest and shortest (but still useful to you) cord you can find, and you're sure to not have problems. They make some pretty heavy duty cords. Best bet is a hardware store.
posted by jaded at 9:01 AM on March 12, 2006

I would think it would be fine. The reason for the disclaimer is probably due to the resistance and heat that would build up if you used a "zip" cord for it.

Also, each connection would build up some resistance, but if the extension cord is heavier than the fridge cord, probably OK, although if I were doing a safety inspection in your house, I would need to note it.

Another thing to do is have a power strip in place of a cord.
posted by Danf at 9:03 AM on March 12, 2006

A little about extension cord safety is at the UL website.. It probably wouldn't be hard to replace the refrigerator cord if you are handy with simple wiring, but a short, fat cord should be OK as stated above (of course, IANAElectrician).
posted by TedW at 9:17 AM on March 12, 2006

Find out the current needed by the fridge. It should be listed in amps -- look for something like "120VAC 7A" -- in this case, it would draw 7 Amps.

If it only mentions watts, dividing watts by the voltage will give you a close measure of the amperage drawn (Not exact, because we don't know the power factor, but good enough here.) So, if it is listed as 120VAC, 600W, we divide 600 by 120, and get 5, so it draws around 5 amps. (You'd think I cherry picked those numbers...)

Now that you know the current draw, you can go buy an extension cord that's rated to handle that current, plus a bit. The rule is round up -- if it draws 7A, you get a 10A cord, and all is good. Just don't round down -- if it draws 18A, you need at least a 20A cord, and I'd buy a 30A, just in case. (In the US, if it drew 18A, it should have a different plug than normal AC devices, in particular, the NEMA 5-20P). Using a 10A cord here is an invitation to a fire -- the conductors can't handle the current, thus, they'll get warm. If they get warm enough, they catch fire. There is a safety margin built into the ratings, but don't count on it. If the cord says it can handle 15A, don't draw more than 15A through it.
posted by eriko at 9:25 AM on March 12, 2006

An air conditioner cord will be absolutely fine. They just don't want you to use the el-cheapo extension cords, plug six refrigerators into one cord, and then be upset because the cord melted and your house caught on fire. A small refrigerator like that should draw much less current than a window air conditioner.
posted by jellicle at 9:26 AM on March 12, 2006

You have to think of those warnings in terms of actuaries and lawsuits. How many fridges, if hooked up to any old random extension cord by idiots, a hundred million times, will start a fire? To a company afraid of getting sued for a bad product, only a handful is too many.

Hence the stern, black-and-white warning. They assume, for their safety, that you are incapable of figuring out what you need to extend the built-in pigtail safely.

In reality, any extension cord rated to handle the current will be OK. You can even get a short extension cord / power-tap with a built in trip at 15A -- those are rated to 15A, (usually -- check!) and have some little margin of safety in that they can trip when exceeded. (And I ran a window air conditioner, drawing just about 15A, on a beefy, 15A extension cord for years with not even a warm-to-the-touch cord -- this fridge will draw less. That AC unit, of course, said to NEVER use an extension cord).
posted by teece at 9:34 AM on March 12, 2006

To agree with everyone so far, yes, you'll be fine as long as you don't use a cheap "lamp-style" extension cord.
posted by fvox13 at 9:34 AM on March 12, 2006

The reason they're warning you is because it takes a lot of copper to move enough power for a fridge or an A/C unit. (or a microwave, for that matter.) So you need an unusually thick extension cord, and the farther you need to go, the thicker it needs to be... each additional foot will waste some voltage to heat generation.

The power company lines aren't very thick because they use much higher voltage, so they don't have to send as many actual electrons to carry the same power. That means they don't need as much copper.

So buy a heavy-duty extension cord, and you should be fine, particularly if you're just going three feet. The measurements above are excellent, and will tell you how thick you need to buy. As a last safety check, after you've been running the refrigerator a few hours, feel the temperature of the cord.. If it's a little warm, that's ok, buf it if's outright hot anywhere, you need a thicker one.
posted by Malor at 9:48 AM on March 12, 2006

At the moment in my kitchen, there is your typical two plug outlet. Plugged into each of those is a 4 plug extension. Plugged into those is a large fridge/freezer, a small fridge, a large TV, a DVD player, a Gamecube, a cable box, a modem, and a microwave.

You'll be fine.
posted by Orange Goblin at 10:15 AM on March 12, 2006

What they said. Go to Home Depot (or someplace similar) and get a heavy duty extension cord. I use one on my air conditioner. No problem.
posted by bim at 10:25 AM on March 12, 2006

There's a specific type of cord referred to as an "air conditioner cord" that should work very well.
posted by 445supermag at 10:36 AM on March 12, 2006

As long as your cord is 14GA and three prong you'll be fine for short distances. A cord labeled for A/C use should meet the requirements but check the tag. Smaller numbers are better.

Lighter gauge cords are hard on compressors because the motor experiences a low voltage condition on start up. The low voltage is caused by the voltage drop across the cord at high amperages. 14GA wire matches the wiring in your house.
posted by Mitheral at 10:46 AM on March 12, 2006

An audiophile would use a similar HD extension cord with the belief that it effectively 'stores/buffers' some current to help with voltage swings in the line.

If the extension doesn't ever get warm to the touch, it is probably doing fine with the load.
posted by buzzman at 10:58 AM on March 12, 2006

Is it safe?

That is an impossible question to answer, yet we pretend there is an answer all the time..

Anyway, the consensus here is fine. But, remember that part of the reason extension cords are bad is the added exposed wire that you can trip over, drop something sharp on, or whatever..
posted by Chuckles at 11:44 AM on March 12, 2006

All good advice so far. To be absolutely safe, check the circuit you're planning to plug it into, at the fusebox or the breaker panel. The fuse/breaker will be rated for a certain number of amps - probably 15. Get an extension cord rated for that many amps and use that. If the fridge were ever to draw more current than the extension cord could safely handle, the fuse would blow before any problems could result. Essentially, this makes the extension cord not the weakest link in your circuit.
posted by pocams at 9:01 PM on March 12, 2006