What Size Wire For A 150 Foot Run

200 amp wires are quite big. They can be used every bit 200 amp ground wires, wires for 200 amp billow, they can be copper or aluminum 200 amp wires. The common question for all these applications hither is this:

What size wire do I demand for 200 amp service?

If you look at the AWG gauge wire nautical chart here, the reply seems to be quite clear (information technology's not that simple, however):

As you can see, the obvious – only wrong – the choice is using a #000 AWG wire for 200 amp service (too known every bit 3/0 AWG) considering it has a 200A ampacity. That, even so, will likely end with you frying the wire.

For prophylactic measures (in order to avoid frying a 200 amp excursion), the National Electric Code (NEC) dictates the post-obit requirement:

Maximum loading for whatsoever co-operative circuit is 80% of the rating of the excursion for ampacity of wire for any load. (NEC 220-2)

This is known as NEC 80% requirement for wire sizing. In the case of 200 amps breakers, this ways y'all volition need a wire with at least 250A ampacity to connect a 200 amp service.

Looking at the AWG wire nautical chart, you volition demand an even bigger than #0000 AWG wire for 200 amps. You lot have to go across the AWG chart at expect at the KCMIL wire chart.

KCMIL wires are bigger and can handle currents of 200 amps and higher. Here is a shortlist of KCMIL wires that can be used for 200 amps:

250 KCMIL wire with 255A amperage.
300 KCMIL wire with 285A amperage.
350 KCMIL wire with 310A amperage.
400 KCMIL wire with 355A amperage.
500 KCMIL wire with 380A amperage.

The 250 KCMIL wire is the perfect size wire for 200 amp service because it has 255A ampacity (a minimum of 250A ampacity requirement is satisfied).

We will show you lot how this 250A ampacity is calculated. On tiptop of that, you volition also demand a bigger wire judge if you want to transport electricity 100 feet or 150 feet away from sub panel (nosotros will show you how to calculate what size wire you need in this example too).

200 Amp Wire Guess Calculation: What Size Wire You Need For 200 Amp Circuit?

To fairly determine the 200 amp wire gauge, you first need to summate the minimum ampacity requirement as per the 80% NEC rule.

In the example of the 200 amp circuit, here is how the calculation looks like (yous accept to leave twenty% extra amps chapters for condom reasons):

200 Amp Wire = 200A × 100% / 80% = 250A Ampacity

That means that you tin can to use a wire that has an ampacity of 250A or higher in lodge to set a 200 amp circuit.

Every bit you can encounter from the list of KMCIL wires above, the 250 KCMIL wire is perfect for a 200 amp service since it has an ampacity of 255A.

Now, if the sub panel is some altitude abroad (50 feet, 100 anxiety, 150 feet, 200 feet, and so on), you will probably have to use an even bigger wire to counted the voltage drib.

The NEC 310-16 requirements cover this nicely:

How To Account For Sub Panel Being 100 Feet Away?

When sending electricity a long way from the sub panel, the voltage volition driblet with the distance. To counter this drop, yous accept to boost the initial amps. That means that the circuit has to handle more amps; in plow, the wire you're using has to handle more amps.

How much more than exactly?

Roughly speaking, the NEC 310-sixteen requirement states that for a 200 amp copper or aluminum wire, you have to add together 20% to the total amps for every 100 feet of distance.

Example: Let's say you lot want to use 200 amp service 100 anxiety away from the sub console. We already know that such a circuit volition crave wires with at least 250A ampacity. On top of this, we have to increase the amps by 20% to go the truthful size wire for 200 amps at such a distance:

200 Amp Wire (100 ft away) = 250A × one.2 = 300A Ampacity

Now we have to find a wire with 300A ampacity or more. If you consult the KCMIL list above, you can see that the 350 KCMIL wire is perfect for 200 amp service 100 feet away. That'south because information technology has a 310A ampacity.

Y'all can make a similar adding for 50 feet (x% addition), 150 feet (30% addition), and 200 feet (40% improver), and choose the corresponding KCMIL wire.

Hopefully, now the 200 amp wire sizing is a scrap clearer.

You should likewise wait into different amp wires and like calculations for: