Not only is it necessary to have some basic electrical knowledge to do some repairs at home, but it is also useful to prevent accidents. Identifying your type of home wiring will make it easier to replace that old electrical outlet, or at least give you some peace of mind in terms of electrical safety.
When it comes to generators, people commonly ask themselves the following questions: What kind of generator do I need? What size generator do I need for my house? How many watts are needed to power my MIG welder/sump pump/air compressor?
If you need a generator size for home, you need more wattage to run multiple home appliances. For homeowners, large dual fuel 10000-watt units are the best option. For your RV, a quiet 3000-watt inverter generator will be great to run your TV, AC, lighting circuits, and fridge.
How to Calculate What Size Generator Is Needed to Power a House
First of all, we measure in watts (W). As a reference, consider that small camping generators offer anywhere between 1,000 to 3,000W, while heavy-duty generators more than 10,000W.
To find out what size generator is needed to power a house according to your needs, you must estimate your energy needs.
1. Choose the devices you want to run
List all essential appliances you have to run during an emergency power outage if you need a generator for your home; such as your AC, refrigerator, and lighting circuits.
2. Use a power requirement calculator.
Pay attention to:
– Starting watts(amount of power needed by the appliance to start)
– Running watts(energy needed by the appliance to run after the initial startup)
3. Choose a generator slightly bigger than your needs.
Reasons:
– A few hundred extra watts available
– Lifespan is not considerably reduced (as it is not run at full load)
– Reduce noise (run at full load makes it noisy)
So, if your power requirements total 1600 running watts, get a generator that offers at least 1800 rated wattage, and get a generator with 7500 rated and 9500 starting watts if the total running wattage of your appliances is 6800 and starting wattage is 8200.
How Big of a Generator Do I Need to Run a House?
With a generator rated at 5,000 to 7,500 watts, you can run even the most critical household equipment, including things such as refrigerator, freezer, well pump, and lighting circuits. A 7500-running watt generator can run all these appliances at once. For RV, a 3000-4000-watt generator will work great.
However, to know what size generator is needed to power a house, you should check the exact wattage of your home appliances to be 100% sure. They are commonly listed on their labels in watts or amps.
Before buying a generator, there is one question you must ask yourself: Do I need the generator to power only the essential equipment or to power the entire house?
Well, if you live in a disaster-prone area where power outages are common, then you should get a larger generator. Despite its higher cost, it could be a great investment and give you peace of mind. However, if you plan to only run it a couple of times a year in case of an emergency, a smaller generator that runs the essential equipment will be the best choice.
Amps vs Watts vs Volts
Watts (W) and amperes (Amps) (A) are different units used to calculate the total power that electric equipment produces or consumes. When it comes to volts (V), most electric appliances sold in the US are rated 120V. Nevertheless, some electrical tools run at a higher voltage, especially 220V; TIG or MIG welders, for instance.
Knowing how many amps your appliance or tool requires to run is easy, just use the following formula:
Wattage= Amps x 120
Example: A 120V MIG welder with 70 Amp draw.
70A x 120V = 8400W
In this case, you would need a generator with at least 8,400 running watts to run your welder.
On the other hand, you can use the following formula if you want to calculate the amperage of your portable appliances with your wattage:
Amps = Wattage / Voltage
What Size Generator Do I Need to Power Sensitive Electronics? Would a Large Portable One Work?
Not really. Conventional heavy-duty generators commonly suffer from higher Total Harmonic Distortion (THD), and a 3% THD is considered the maximum threshold for the power to be safe for modern electronics. Standby and state grid generators operate well below this threshold, but not typical heavy-duty portable generators. Modern electronics such as flatscreen TVs or laptops would be damaged by them if used for continuous long hours.
The good news is that portable inverter generators can be safely used to run these electronics as they do not share this problem. Despite most inverters are too small to run a whole house, they come with a parallel capability that means you can double your total power output by using two inverter generators in parallel.
Just keep in mind that if you decide to use a portable generator, whether it is an inverter or a conventional generator, never operate it without a transfer switch. By doing so, not only would you prevent damaging your household appliances and the electric grid in the entire neighborhood, but also causing life-threatening electric shocks.
