What Size Breaker For 40 Gallon Electric Water Heater

what size breaker for a hot water heater

Does your electrical water heater go on tripping the billow? Did your heater overload without notice? With just these few questions, it is articulate that y'all're having a problem matching your appliance with its safety device.

What size breaker for a hot water heater, you say? The standard size for most heaters is xxx-amps. Even so, this billow ampacity doesn't necessarily piece of work for every h2o heater there is.

At that place is a formula for finding the correct billow size, but at that place are other essential factors to talk nigh later on in this commodity.

Understanding Your Water Heater

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Upon purchasing an electrical water heater, one of the nigh common mistakes of a homeowner is not checking its amperage. Some heater tanks only accept a characterization for their voltage and watt requirements simply never their ampacity.

It is best if you lot look for your tank specifications from the retailer or the brand manufacturer itself. Your heater must be your footing for determining the right breaker size. To ensure rubber, here are the three factors you should consider:

Voltage- The volts of your boiler plays an integral function in a healthy excursion. You can plug an boilerplate heater to a 220 or 240 Volts outlet based on your tank size and wattage.

Wattage- Take your heater's wattage requirement into your list. Knowing its wattage is a cracking advantage if your device usually pulls an immense amount of ability for its tank size and other features. Information technology will help y'all search for a suitable breaker to handle it.

Wire Size- Lastly, it is essential to know what cable type is compatible with your hot water heater breaker size. An incompatible size or reused faulty wires can cause more risk than welfare for your heater and billow.

A Breaker Size Solution: What'due south the Formula?

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If you lot're clueless about the amp size you'll use, doing a simple calculation is the respond. Since yous already know the wattage and voltage of your water heater, all you need is to follow the Ampere formula, which is I (amps) = P (watts)/ Five (volts).

For example, I have a heater tank of three,000 watts that needs 120-volt power. To go its amperage, you need to dissever your watts by volts.

Solution: I = P/V

I = 3000 watts / 120 volts

I = 25 amps

Now you may be thinking, a device with 25 amps needs a breaker size with the same value. Well, that's where overloading and over-tripping start to happen.

There's a regulation set by the National Electric Code (NEC) wherein you demand to stay at 125% of the maximum continuous load. This step is vital to get the safe amount for your electric water heater breaker size.

For the instance earlier, use the continuous load rule: 125% x 25 amps = 31.25 amps. Then, you can become the closest amp size which is 35 amps. For a 35-amp CB, the Square D past Schneider Electrical HOM235CP is a highly suggested product.

If you lot have a twenty-amps breaker dedicated to your 25A water heater, expect that your heater will constantly trip it. Giving space for your breaker will let a power surge without tripping.

To better understand, yous tin picket this video from House Wiring T.V.: correct way to size your water heater wires and Breaker size!!!! – YouTube

What Size Breaker for xl and fourscore-Gallon H2o Heater?

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Most families apply a tank size of xl to 80 gallons for a water heater — depending on how much they rely on warm water daily.

To find out how many amp breaker for water heater of these tank sizes, you'll need their wattage and voltage, then use the solution earlier.

For a xl-gallon heater, the average capacity is 4500 Watts with 240 Volts. Again, I = P/Five; 4500W/240V = 18.75 amps. Then considering the continuous load (125% 10 xviii.75A), we'll get a total of 23.4 amps.

With our reply, a 40-gallon water heater needs at least a 25-amp breaker, the closest to the amperage value. Nonetheless, I highly recommend using xxx-amps for a safer breaker size.

Meanwhile, an lxxx-gallon heater powered by 5500 watts and 240 volts, volition result in 5500W/240V ten (i.25 continual load) = 28.64 amps. Meaning, a 30-amp dedicated excursion breaker is enough.

Pro-tip: Although a 30A breaker sounds like it'south not enough for an 80G tank, installing a 40A won't protect the device in case of an overload. A billow amperage that'south much college than necessary won't trip when needed.

What'southward the Correct Wire Size for a Water Heater?

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The connexion of a water heater to its breaker won't work well if the wiring is incompatible. Make sure that the amperage of your heater matches its wire size. Y'all can refer to this list:

20-amps = 12-estimate wire
25-amps = 10-estimate wire
30/40-amps = viii-gauge wire
Other large heaters up to fifty-amps = 6-gauge wire

Also, consider your breaker size for water heater. 30-amp circuit breakers, normally used for a big banality tank, require a 10-2 not-metallic or MC cablevision. This blazon of wire is suitable for showtime loads of 40-amps and a constant load of 35-amps.

Preventive Measures Before Buying a Excursion Breaker

When choosing the correct h2o heater circuit breaker size, yous should be delicate nearly the amp difference between the breaker and the heater. Yous must get the correct size. A breaker too large or besides piffling can risk an electric hazard.

If the breaker is besides pocket-size for the h2o heater's ampere requirement, expect that your CB will trip continuously. Not only that, too much on and off of the heater tin cause internal damage. Do not have your water heater share a circuit with other appliances, and please upgrade the breaker if necessary.

A billow with a college amperage than intended doesn't immediately hateful that information technology's safer for the heater. If the tank suddenly has a short circuit or overload, your breaker will disregard the event — no protection at all.

Conclusion

Knowing what size breaker for a hot h2o heater is not that exhausting if you assemble the correct data. But by understanding the three wire heater elements — voltage, wattage, and wire size, you tin become the proper billow size.

A simple calculation volition also practice the piece of work, but go on the breaker size almost the corporeality of your answer (the bodily amp size of the heater).

An electrical water heater typically uses a 30-amp breaker, and so something like the Q230 xxx-Amp Double Pole Blazon QP Circuit Breaker will exercise the work well.