What Size Service Cable For 125 Amp

what size wire for 12 -amp breaker

What size wire for 125 amp billow? The answer is rarely simple. You lot'll need to take into consideration the required electrical load, distance, space available in the panel, temperature ratings, etc.

Specificity is the key in short. If y'all're a homeowner and need 100A delivered to a 125 subpanel within 100 feet at 75 degree C, for instance, then yous'll demand, according to universal recommendations, a #1 copper or a #ane/0 aluminum wire. I'll explicate further and share some helpful tips below.

The Exact Electric Load and Temperature Rating are Important

125-amp-wire-size

Going back to the example I share higher up, if nosotros simply crash-land the load to 125A, y'all'll already need a two/0 aluminum wire instead, which is obviously entirely different from the 125 amp wire size copper I mentioned. It'southward also advised to increase your excursion breaker capacity to 175A if that's the case to ensure safety.

How exercise we calculate the load based on the circuit breaker's ampere rating? The general dominion of thumb is to multiply it by 0.viii. For case, 175A x 0.8 is 140A, while a 150A breaker only supports a total of 120A. This is why information technology'southward recommended to utilise a 175A and a bigger 125 amp wire size of ii/0.

What about the temperature rating? To me, there'southward no better reference for it than this tabular array. The wire you employ determines the temperature rating you need to follow and the respective capacity recommendations.

As yous'll meet, they're still proportional to the usual breaker and wire size suggestions fabricated in all countries worldwide, as represented in this other table approved by Canada's National Electric Code.

I could not find a better video reference for what size to use based on the usual real-earth appliances and their average electrical loads than the following. I recommend you watch information technology to gain more insights.

Nosotros Can't Ignore Distance, Too

You'll also need to calculate the exact distance you need when knowing the right 125 amp breaker wire size. If your project involves wiring from your main circuit breaker to your garage, and so you'll demand to consider the altitude in feet. It's just equally of import as knowing the amps when calculating voltage drop index, after all.

Sometimes, I use this calculator to confirm my requirements. However, I don't always stick to it, because I prefer calculating based on practical load. The practical load takes into consideration what each apparatus needs to run instead of the possibility of the breaker tripping.

In near cases, I don't need to calculate for voltage drop, especially if the distance doesn't exceed the voltage (east.g. 360V can cover 360 feet). If it does or is equally shut every bit possible to it, that's the only time you demand to make voltage drop calculations.

According to the Electric Engineering science Portal, to summate for voltage drop, yous need to get the exact ampere-feet you're dealing with. It's usually calculated by multiplying load or circuit current (in amperes) with the exact length of your circuit. After, separate it by 100 then multiply information technology by the VD values found in the tables.

What If You Don't Have Plenty Space Anymore in Your Panel

wire-for-125-amp-service

This is another common issue I demand to accost here because most homeowners detect this out too late and end upwardly with some other trouble. Y'all observe that the appropriate wire size can't fit in the infinite bachelor in your panel anymore. This is exactly why most electricians encourage homeowners to get every bit much space as possible for their main console or subpanel.

One time I encounter cases like these, I more often than not advise people to invest in a subpanel next to the main console. If it's a 125 amp panel, then you tin utilize a 100A billow on the main panel to feed the breaker. The new sub panel must always have the same ampacity rating as the panel that is feeding information technology.

When in Dubiety, Don't Hesitate to Inquire for Guidance From a Licensed Electrician

If you still feel lost (and that's understandable, given the technicalities), there's no shame in asking for aid from your local electrician to know the ideal wire for 125 amp service. I'll even stress that it's the safest road to take if you aren't also confident with your DIY skills when treatment electric systems.

Incidentally, if you're non already enlightened of it, make sure that your municipality actually allows unlicensed citizens to exercise electrical work. This goes for both residential and commercial buildings. After all, there'due south always an inherent risk involved, not just to your family merely also to the nearby properties and people as well should an accident lead to fire.

Decision

To sum it up, always know the specifics beforehand. Take note of the electric load, temperature rating, and, sometimes, even the distance required for the entire wiring if it's necessary. This is the only fashion for you to know what size wire for 125 amp breaker.

Should you need adjustments, don't hesitate to consult a professional because anything less could only heighten your risk. It will also save yous money and time in the long run.