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Purchasing a generator is often a major investment for a business or homeowner. It’s also something most consumers don’t do very often, so there’s a lot of confusion about which fuel type to use (natural gas, diesel, and propane), which brand is best, and especially what size generator is adequate.
To find out which generator size is best suited to your usage requirements. Find out about power requirements and more in BISON’s comprehensive guide.
Why choosing the right generator size is critical
It can be tempting to save on generator size, significantly if it could save you a few thousand dollars. However, choosing a too-small generator for your application can lead to disaster. Not only can you damage the equipment powered by the generator, but you can damage the generator itself.
Here are some more benefits of using generators that are too strong rather than too weak:
- Extended lifetime of generators
- Limits incidence of unexpected system failures
- Consistent production performance
- Limits incidence of capacity overloads
- Reduces potential for asset damage
- Increases personnel safety
- Reduces risk of overheating and electrical fires
- Increases ease and speed of maintenance
- Reduces maintenance frequency and cost
What are the factors to consider when choosing a generator?
As China BISON suggests, choosing the right size generator is a process that involves evaluating the power of the appliances you need to power. It’s important not to over-invest in a portable generator that provides more power than your appliances need.
There is no need to purchase a larger generator unless you foresee the need for additional power and are prepared to store additional gasoline. Some of BISON’s high-capacity portable generators can consume about 20 gallons of gasoline per day.
The size of the generator you need can be either a traditional portable generator or an inverter generator. The latter electronically regulates the engine to supply power more efficiently. Although an inverter generator has a higher initial cost compared to a conventional generator of the same power, it offers unique advantages.
The BISON generator suppliers advise you: “If you are willing to pay a higher upfront cost for a quieter-running, more fuel-efficient unit that may save you money in the long run if used regularly, then an inverter should be your first choice.
Cina BISON can provide comprehensive guidance to help you select the best generator for your needs.
A step-by-step guide to choosing the right size generator
Step 1: Determine your power needs
The first step in sizing a backup generator is determining your power needs. In the event of a power failure, generators act as a source of electrical energy. To determine your power requirements, list out all the devices that you intend to operate using the generator. It could be that you require a generator to operate heavy-duty machinery at a construction location. Alternatively, you might need a power generator set to supply electricity to your entire home or a full building during a blackout.
As the total wattage is a crucial factor in choosing the right generator size, it’s important to thoroughly understand which devices you need to supply power to and their individual energy needs.
Step 2: Calculate your electricity usage
After determining your power needs, calculate your electricity usage. This involves determining each device’s starting and running wattages on the list. Starting watts are the power needed to create the device while running watts are required to keep the machine running.
List all items that require power. Determine each appliance’s starting wattage (the amount of energy necessary to turn the appliance on) and operating wattage (the amount of energy needed to use the appliance). These numbers are usually engraved on the device and documented in the owner’s manual. Calculate your total power needs by adding these kW or KVA figures.
For devices that measure in amps, you can convert amps to watts using the following formula:
- For resistive loads (the most common type): Watts = Amps x Volts
- For reactive loads: Watts = Amps x Volts x load factor
The load factor is actually the ratio of your electrical energy usage (kWh) to your peak demand (kWh). You can calculate it by consulting the data in your utility bill and using the following formula:
- Total kWh for the previous month / (peak demand for the period x 30 days x 24 hours)
If you lose your manual, you should be able to find wattage details online. However, if you are unsure of the power consumption figures for a particular device, you can use approximate figures.
Once you know the estimated wattage required, choosing a generator size is much easier. Whatever numbers you come up with, select a generator with a capacity 10-20% larger than your requirements. This will give you some leeway when you update your device and need more power. It also helps you manage “de-rating,” when a generator performs below what the manufacturer claims it is capable of due to adverse operating conditions such as extreme temperatures or high altitudes.
Step 3: Estimate starting watts vs. running watts
Next, estimate the difference between starting watts and running watts. Some appliances, such as refrigerators and air conditioners, require more electricity to start than to run. It would help to choose a portable generator with enough starting power to handle these devices.
Running (Rated) Watts: This represents the continuous power that is necessary to keep your devices operational.
Additional Starting (Surge) Watts: These are the extra watts that are required initially for a few seconds when powering up devices driven by motors.
Want to know more: kw, kva, and power factor
Running watts and starting watts examples
Step 4: Choose the correct fuel type
Backup generators can run on different fuel types, including propane, natural gas, and diesel. Consider which fuel is most readily available in your area and which will best meet your needs.
Step 5: Consider generator type and features
To make an informed decision, it’s essential to understand the two main types of power generators: portable and backup generators. Portable generators are less expensive and mobile, while backup generators are more expensive but provide more power and can be connected to your home’s electrical system. When choosing a generator, you must consider your specific needs and preferences, such as automatic start and noise levels.
Need help figuring out how to size your generator?
To avoid the trap of not knowing how to size a generator, consider enlisting the help of a BISON portable generator specialist.BISON can help you find the right generator for your specific needs.
China BISON’s power experts will work with you to understand your needs and help you choose the right generator for your business. Please contact us to speak with one of BISON’s friendly staff.
choose the right size generator People also ask:
Appliances such as light bulbs, coffee machines, or water heaters, known as resistive loads, consistently consume the same amount of power from the generator.
On the other hand, reactive loads, which often include appliances with motors like refrigerators, freezers, or washing machines, require varying amounts of energy from the generator. This is typically due to the extra power needed for startup. For example, refrigerators also have an internal fan that intermittently operates to maintain a uniform temperature.
When in the market for a generator to energize your home, it’s crucial to first establish which appliances you’ll require to be powered. Here’s some helpful guidance for making your generator selection:
Home Generator Selection Criteria
- A generator with a capacity of 5,000 watts can sufficiently operate the basics — lighting, fridge and freezer.
- A generator rated at 15,000 watts is capable of offering a more relaxed lifestyle — powering lights, fridge, freezer, central AC, water heater, oven/stove, microwave and television.
- A generator boasting 25,000 watts can meet the majority of residential requirements — handling lights, kitchen devices, central AC, water heater, laundry machines, garage door opener, and various home electronics.
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