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What Size Generator Do I Need for 100 Amp Service?

Generator is one of the most useful appliances as it supplies electrical power during a power outage. It provides guaranteed power for all the major appliances as well as safety systems during an emergency. Normally, generators come in various sizes with different electrical and physical configurations.

Generator size for 100 amp service:

The size depends on the appliances that require power with the backup generator and also how many appliances will run at a time under it. Typically, for 100 amp service, it takes a minimum 24 KW for a moderate sized home’s service; which initially determines the size of the generator 20-24 KW.

Obtaining the right size of generator is required for maximum power usage and proper utility. Oversized generators go through inefficient power production for consuming more energy and as a result causes unnecessary operational expenses. Undersized or too small generators will operate slowly, will cause overheating and get damaged more quickly.

How to calculate

To determine the size, first it’s really necessary to get the proper information of the power information for each appliance. For that  determine both the running watts and also the starting watts. Appliances like laptop, tv, computer or lights have equal running watts and starting watts where air-conditioners, fridge, coffee machines, hair dryers and some other appliances have 2-4 times greater starting watts than their running watts for their electric motors, compressors or heating elements. You can’t ignore the running watts because the appliances won’t run if your generator can’t produce more power than the starting watt of your appliances.

If you have the information of all the appliance’s power in watt you easily transfer it into kilowatt and get the idea of the right size. However, if the power information is written into the amp, you’ll have to take the measurements by using an ammeter. Put the ammeter on each leg of the electrical service and you’ll get the result.

Get the amp and service volt:

For a small to medium home’s service, 100 amp service is sufficient enough to fulfill the minimum requirements and initially, for a moderate home’s 100 amp service, it requires a minimum 240 volt.

Get the equation of watt:

Now multiply the amps by the volts and you’ll get the particular power information for the particular item. For 100 amp service and 240 volt,

W= I×V = 100× 240= 24000 Watt.

Convert it into kilowatt hours:

All you need to do is convert the Watt into kilowatt hour by multiplying the watt with hour and dividing it by 1000.

24000×1/ 1000 = 24 kilowatt per hour.

Use the number to determine the size of the generator. Another important information is, it’s suggested, not more than 80 percent is required for the power load of a generator. For 24 kilowatt, 80 percent would be 19.2 kilowatt; The maximum usage will be close enough to the final number. It will meet your exact power requirements of the generator and there will be no waste of the power or the money at all.

What can you run on 100 amp service?

For a small to medium size home, not bigger than 2500-3000 square feet, 100 amp service is sufficient enough. It is capable enough to supply an electric range and general lighting. Without any hassle, you can use a few electric appliances, such as a water heater, or clothes dryer or iron or electric filter. If you use gas appliances instead of electricity, and don’t have a central air conditioner or an electric heater, this one will be the right choice.

However, 100 amp service is often used in older homes and even sometimes considered as outdated as it can’t support modern home appliances. 100 amp service doesn’t have higher capacity; it’ll only be a good choice, if your home doesn’t have many modern appliances. It can’t even serve electric heat and air conditioning to run for their insufficient capacity and so, you’ll require a minimum of 200 amp service. In fact, to serve lighting and all other basic needs in a larger home, bigger than 3000 square feet, you may require 250 amp service.

Factors to consider for choosing generator size:

Selecting the proper generator size is important, and it depends on a few different things. Actually, choosing the correct size generator involves thinking carefully about the generator’s intended usage. The qualities of the generator are the primary deciding factor when selecting an ideal generator for industrial usage because industrial applications necessitate high voltage and an abundant supply of energy. The budget is also a major factor.

Consider when selecting the generator for your home are the warranty, fuel consumption, and capacity to handle additional loads. These are important considerations. For safety reasons and while keeping costs in mind, a generator should also have automated shut-down functions.

Voltage supply for devices: 

When selecting a generator, it is critical to consider how many rooms must be powered by generators and how many devices each device carries. If they’re aren’t many rooms, a medium-sized generator of five to eight-ten kW should be adequate to power the fans, TVs, and lights.

It may be necessary to supply an additional kilowatt of generator power if there are several rooms. In addition, the choice of generator is influenced by the devices carrying high voltages; if the device is an air conditioner or heater, it will consume a lot of power.

Costing:

Cost is a consideration when looking to purchase a generator of the ideal size. When a larger generator is needed to give greater power to the linked lines, choosing a smaller generator will result in a generator that will not warm up effectively, necessitating the purchase of a new generator, which will result in increased costs.

When purchasing a generator, the owner should be aware of the plugged-in lines and how much voltage each device carries. If there is a need for less power supply, a generator producing a lot of kw of energy may produce more carbon, and over time, the generator will sustain damage.

Fuel usage:

Since fuel is required to run generators, choosing the right fuel is very important. Kerosene or other petrol fuels are typically utilized in homes, while diesel is mostly used in industries. Aspects for a generator that will aid in decreasing the cost and will run the generator properly are the typical fuel daily needs and what sort of fuel will be required.

What happens if you undersize or oversize a generator?

The generator’s size has a significant impact on how effectively it operates. The working power of the generator will be decreased by an undersized or oversized generator. The working rate of the generator will be reduced if it is too small, and there won’t be enough power supply to level out the voltage and prevent the gadgets from shutting down from improper voltage. Oversized generators consume more energy and operate for longer periods of time, which causes them to heat up quickly and undergo damage more quickly.

The likelihood that the generator may produce too much carbon when it is oversized is high, which will lower the generator’s capacity to supply enough power. The larger generator will consume more fuel, which is also a poor economic decision. Less voltage will prevent an oversized generator from warming up and producing an adequate load to power the gadgets.

Therefore, a generator that is undersized or oversized will have a number of issues. A generator that is too undersized will operate slowly or maybe stop completely. Additionally, it will have an impact on the generator’s output. If the generator’s size changes in relation to the providing voltage, the generator’s ability to operate quickly will be impaired.

Will a 12kw generator run my whole house?

The answer will depend on how many electrical devices are plugged in at the same time. Depending on how long and how many devices are being operated, a generator with 12 kW of electricity may or may not be sufficient. A 12 kW generator can power the typical home, but it’s necessary to keep in mind that some items, like air conditioners and heaters, may require more electricity.

However, if this 12 kW generator is used wisely, it can provide power for habitation for eight to nine hours per day. A seven or eight-kw generator is sufficient to power the lights, television, and fans in the home.

However, a 12 kW generator is required if the home has electric heaters and air conditioners, which typically consume more energy. It is also not recommended to plug in all of the devices at once because this will result in an increase in energy usage.

Final thoughts

It’s necessary to choose the right size as both oversized and undersized generators have negative impacts. The size of the generator depends on the devices plugged in simultaneously and power the gadgets consume when in use. For 100 amp service, you’ll need a minimum size of 20-24 kW/h generator.