Why do North American outlets handle a smaller wattage?


[QUESTION HAS BEEN ANSWERED. THANKS TO EVERYONE WHO CONTRIBUTED TO THE DISCUSSION.] So, let’s start off with this: Volts * Amperes = Watts. The standard North American AC voltage is 120V and the standard amperage is 15A. That gives us 1800W to work with.
Let’s take a look at the British standard. BS 1363 is (most commonly) 230V and 13A which gives us 2990W. German standards also allow up to 4000W if I’m not mistaken. What caused these differences?

In: 2

You basically gave the answer yourself. Current. With voltage being fixed, current is limited to what the wire can handle. The given gauge can handle only a maximum amount of current. If you wanted to deliver the same power in both 230 V and 120 V areas, in the latter the wiring would have to use thicker wires with less resistance. The more current you push through a wire the hotter it gets, so if you overload a wire, you create a fire risk. That’s what breakers are intended to prevent.


The US developed its electrical system pretty early and decided to go with 120V. Electricity was considered really dangerous and lots of issues and this was about as far as anyone wanted to push it, along with a lot of practical and technical challenges of actually delivering electricity. Even Europeans were on this bandwagon at first.

So the US started to build out this system, very substantially, and lots of products were made for it. It wasn’t that long before everyone, including the US figured out 120V is actually a bit low and we really should have just gone with like 230/240v instead– they had thought about it before, but decided against it as being too dangerous and impractical– it wasn’t a bad assumption at all, it just ended up the lower voltage just wasn’t as good as the higher one, it still worked great, just that it could have been better. But at that point, the US system was too deep to change, but other countries could far more easily start anew or change to higher voltages or for whatever reasons had already used higher voltages or other systems.

In North America there is also 3 phase power used in Industrial settings and many Apartment buildings where the offset is 120 degrees instead of 160.

You get 400 volts this way.