How many watts can a standard wall socket support?

[Ozkar]

What is the maximum number of watts that a wall socket can provide?

[Plissken]

About 1600W. Usually a wall socket in the USA is wired on a 15 amp circuit, shared with other wall sockets. So the total shared by all the sockets is limited to about 1600W combined.

[Blue_Sky]

Plissken is right - 15 A.
You'll want to see if you can figure out which wall sockets are on which circuit. If you plan on drawing 1000+ W from one socket, I'd make sure that it is alone on the circuit and that the wire is in good condition. 15 A doesn't generally call for a very large diameter wire, but that isn't a good thing if this is a constant draw.

[cb95014]

Most of the circuits in my house are 20A, so check your electrical panel for the rating of the breaker.

20A @ 120V = 2400VA ~= 2400W (but often less, depending on the quality of the power supplies involved)

Each standard US two-prong plug has contacts rated up to 15A.

20A outlets are also available, and the prongs are oriented ' -- | '. Obviously this is only useful if the circuit's wiring and breaker can handle 20A as well...

[sjoukew]

In the Netherlands (Europa) we use 220-230V and the standard fuses are 16A.
Therefore we get 220V*16A=3520W.

[Rusty075]

The above advice is all completely correct, but note that it generally true only for new or new-ish construction....


...if your place in Queens is like most places I know in Queens, you might want to limit yourself to 10-12A at any one circuit, just in case.

[aristide1]

Circuit breakers limit current, but that doesn't address other issues.
The gauge of the wire and the rating of the outlets come into play. Per the prior post I've been in older homes with 15 amp "circuits" but the outlets were 2 prong 10 amp jobs. I replaced critical ones with the "proper" 15 amp outlets that ran cooler.

Now I am in an older home wired with 2 wire romex, ie the box itself is not grounded, except for the recent added circuits for the microwave and the living room a/c. Replacing the outlets here is not wise, as they are all 3 prong and would provide an illusion that grounding is there when it's not.

I also wouldn't attempt to push 15 amps through a cheap 18 gauge(?) extension cord.

Final answer - it depends.

[aristide1]

The above advice is all completely correct, but note that it generally true only for new or new-ish construction....


...if your place in Queens is like most places I know in Queens, you might want to limit yourself to 10-12A at any one circuit, just in case.

Old time cloth and/or rubber insulated wiring that just disintegrates when you touch it?

[Rusty075]

Old time cloth and/or rubber insulated wiring that just disintegrates when you touch it?

In that case: invest in the best homeowners insurance money can buy, and keep a fire extinquisher with you at all times.

[aristide1]

Old time cloth and/or rubber insulated wiring that just disintegrates when you touch it?

In that case: invest in the best homeowners insurance money can buy, and keep a fire extinquisher with you at all times.

You know what? Its not that bad. Two things kill such insulation:

1. Heat, specifically near light fixture boxes and heavily used outlets.
2. Moisture, like cellars.

I had all wiring in the cellar replaced. Upstairs the electrian added boxes about 2 feet away. The remainder of the wiring is OK. New circuits handle the really heavy loads for the most part.

For stuff in walls it was Radio Shack to the rescue. I bought heat shrink tubing rated at what? Like 600 volts? I disconnected outlets and then put the tubing over the wires. I shrank it and reassembled it all. It's not perfect but it's a huge improvement in safety. In the dining room the electrician just wrapped the wire with electrical tape, I thought my variation of his solution was better.

One would hope then a short would be handled by the curcuit breakers.

And there lies another problem. You don't really want a 20 amp curcuit on say one that normally only handles 3 desk lamps, but you can't really tailor each circuit by load, unless you plan on going back to fuses. Which is not a bad idea. On occaision a circuit breaker can be overloaded to where the contacts weld themselves together before it trips. It's very rare, but my last electrician has seen it happen.

[mcoleg]

while a wall socket in the us is rated to 15A, it's usually recommended (ask your local electrician ) not to load it past 13A. They get gunky, rusty, they are surrounded by paper walls and dry wood, for goodness sake. the most common cause of fires. If it's an old socket, might as well keep it even lower unless you can replace the wiring.

[Beyonder]

Most of the circuits in my house are 20A, so check your electrical panel for the rating of the breaker.

If someone (the OP, in particular) is seriously considering running at or near the limits of the breaker, I'd also take the time to make sure you have appropriate gauge wire hooked up to that breaker.

A lot of homes with amateur wiring work will have improperly small gauge wire running to an over sized breaker, generally because the homeowner (or whomever) was tired of having the breaker trip (dumb idea, but it's a lot easier than figuring out why something is tripping). This is a fire hazard, and will get flagged by most (competent) home inspectors.

[derekva]

while a wall socket in the us is rated to 15A, it's usually recommended (ask your local electrician ) not to load it past 13A. They get gunky, rusty, they are surrounded by paper walls and dry wood, for goodness sake. the most common cause of fires. If it's an old socket, might as well keep it even lower unless you can replace the wiring.

If the wiring is in good shape and you use a hospital-grade plug, you can probably go to the full 15A (although you will risk blowing the circuit breaker). On the other hand, it is better to balance your power load (and let's be honest, how often are you putting a 15A load through a single outlet, unless you are running a rack of servers?).

-D