What Size Wire For 220 Volt 15 Amp Service

What is 20 amp breaker wire size? If you're planning to fix up a 20 amp excursion, you will need the correct wire gauge for 20 amps. Note: twenty amp 240 volt circuit tin generate upwards to 4,800W wattage.

Here the answer seems obvious:

You need a 14 gauge wire on a 20 amp circuit, right?

Non quite. This is the most common mistake homeowners make when it comes to what size wire you need for twenty amp service. Information technology'southward quite understandable why the error is made. #14 AWG wire has a 20A ampacity. It seems the perfect choice for a 20 amp excursion.

Why this is a wrong selection?

Considering twenty amp current will probably fry a #fourteen AWG wire. To forestall this from happening, the National Electric Code requirement is set to aid you choose an adequate wire size for a xx amp billow.

The NEC code, Chapter iii, Segment 220-2 states that:

Maximum loading for any branch excursion is fourscore% of the rating of the circuit for ampacity of wire for any load. (NEC 220-2)

This is known as the 80% NEC dominion for electrical wire sizing. That means that if you lot desire to have a 20 amp circuit, you demand a wire with at to the lowest degree 25A ampacity. These extra 5 amps (or 20% of the total current) are a safety measure that prevents you from overloading the wire.

That also means that the #xiv AWG wire with 20A ampacity is not sufficient for a 20 amp circuit. The perfect wire gauge of a 20 amp breaker is the #12 AWG wire. This is a bigger wire with 25A ampacity and tin handle twenty amp electric current while likewise satisfying the NEC fourscore% rule for condom.

You can consult the overall wire gauge chart here. This is the screenshot for the xx amps excursion we are going to delve in this commodity:

We will look into how y'all tin can calculate the ampacity you demand from a wire in a twenty amp circuit. On tiptop of that, we volition too look at an actress NEC recommendation for 20 amp services with sub console 100 feet or 150 feet away (yous need to account for voltage drib; boost amps by xx% for every 100 anxiety abroad from the sub console).

What Wire Approximate For 20 Amp Circuit? (Apply NEC 80% Rule)

When y'all are trying to figure out the wire judge for 20 amps, y'all normally look at these 3 wire sizes:

#fourteen AWG with 20A ampacity.
#12 AWG with 25A ampacity.
#x AWG with 35A ampacity.

Despite the common sense conclusion, #14 AWG is never used for a 20 amp excursion. Instead, we use bigger #12 AWG wire (close to 20 amp sub panel) and #10 AWG wire (100 feet or more from 20 amp sub panel).

Why is that?

Well, we need to account for the NEC fourscore% dominion. Here is how you business relationship for it by computing the minimal require ampacity of a wire for xx amp service:

20 Amp Wire = 20A × 100% / lxxx% = 25A Ampacity

This means you demand a wire with at least 25A ampacity for 20 amps, and the #xiv AWG with 20A ampacity just doesn't cut it.

Which is the all-time wire gauge for a 20 amp breaker?

#12 AWG wire. This is usually a copper wire with 25A ampacity at a median temperature (75°C or 167°F).

If, however, you are sending electricity away from the sub panel at a considerable distance, you would need a bigger wire still. This has to do with the voltage driblet:

What Size Wire For xx Amps At 100 Feet Abroad?

When you send electricity 100 feet or more away, the voltage will inevitably drop. We talk virtually the voltage drop. If you still want to get twenty amps on the whole circuit, you have to boost the amps to counter the voltage drop.

Boosting the amps is unremarkably connected with a bigger wire. You're sending a higher-than-twenty-amps current 100 feet away (or more than).

According to the NEC 310-16 rule for copper and aluminum 20 amp wires, you need to increase the amps by 20% for every 100 feet.

We already know that you demand at least a 25A ampacity wire for a 20 amp circuit. If you want to apply those 20 amps 100 feet abroad, you need to increment the minimum ampacity the wire can handle past twenty%. Here is how you calculate the ampacity now:

20 Amp Wire (100 ft away) = 25A × 1.2 = 30A Ampacity

That means that the #12 AWG wire with 25A ampacity won't be plenty whatsoever more than. Which wire should y'all choose for 20 amp 220 volt circuit 100 feet away from sub console?

#x AWG wire is perfect. Information technology has a 35A ampacity, more than than the required 30A ampacity.

You lot can summate similar minimum amp requirements for a 20 amp circuit at whatsoever distance:

l feet from sub panel. Add together 10% and you get 27.5A Ampacity. That'due south #x AWG wire.
100 anxiety from sub panel. Add 20% and you go 30A Ampacity. That's #10 AWG wire.
150 feet from sub console. Add 30% and you get 32.5A Ampacity. That's #10 AWG wire.
200 anxiety from sub panel. Add forty% and you go 35A Ampacity. That'southward #10 AWG wire.

As yous tin encounter, shut to the xx amp console, you use #12 AWG wire. For a xx amp circuit 50 feet or more than from the sub console, you employ #10 AWG wire.

Hopefully, this clears things a bit. If you accept any questions regarding 20 amp wire sizing, you can pose them in the comments below and nosotros will endeavour to assist you out.

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