How Many Amps Is A 20kW Generator (And What Can You Run On It?)

20kW (20,000 Watts) generators will typically give you around 83 amps per leg. Generators of this capacity are often a popular choice, and considered an easily budgetable model. 

Most 20kW generators are air-cooled, which means they take in cool air from the atmosphere around them and blow the air across the internal generator set to keep it from overheating. Nearly every portable generator up to 22kW has an air-cooled generator.

On average, a 20kW generator will cost around $5000, and they usually include a 200-Amp Automatic Transfer Switch (ATS). An ATS connects your standby generator to your home.

How Many Amps Is A 20kW Generator (And What Can You Run On It?)

Usually, the electricity in your house is powered through the utility which is connected to your home’s main electrical panel. But an ATS works as the “brain” of your electrical system.

During a power outage, the ATS will automatically recognise that the generator needs to be powered on - so it will do it for you. When power is restored to your home, an ATS detects this too and will automatically switch your home back to utility power. 

You need to make sure you match the size of your ATS with the size of the load center it will be connected to. Usually, 20kW generators are connected to a 200-Amp load center, so they come with a 200-Amp ATS. To check the size of your load center, check your breaker panel. 

What Can A 20kW Generator Power? 

If your house is no more than 2500 square feet, then a 20kw generator should suit all of your needs. 20kW generators work best if you have gas heat and hot water, and are particularly useful if your range top runs off of gas and not electricity. 

A generator with a 20kW capacity should run most of your home’s appliances and receptacles including lights and a 5-ton central air conditioning system. 

Some of the essential electrical circuits you’ll want to power with a generator include:

  • Kitchen receptacles including refrigerators and freezers
  • Downstairs lights (if you live in 2 story building)
  • Fan blower motor for gas heat 
  • Security systems 
  • Garage door
  • Central air conditioning unit

If you live in a small house, you do not need to worry about essential circuits, as a 20kW generator should power your whole house. 

Frequently Asked Questions 

Is It Safe To Run A Refrigerator Off Of A 20kW Generator? 

It’s perfectly safe to run a refrigerator off of a generator as long as the generator has a higher watt allowance than the watt consumption of the refrigerator.

On average, the starting watts of a refrigerator are around 800-1200 watts, so a 20kW generator (which is 20,000 watts) will be more than efficient at powering a fridge. 

How Much Does It Cost To Install A 20kW Generator?

Typically, 20kW generators cost between $4,500 and $4,800. Most generator manufacturers offer a 5-year limited warranty, which usually consists of 5 years for parts and 2 years on labor. Some offer a 5-year comprehensive warranty too. 

The cost can also differ depending on where you live. If you need a cold weather kit, a 20kW generator typically costs around $4,900. However, if you live somewhere warmer and don’t need a cold weather kit, this usually costs around $4,600. 

You also need to factor in installation costs. If your electric meter and gas meter are located next to each other, or they’re both on the same side of the house the installation costs will be less.

However, if your generator is located away from either your gas or electric meter, expect to pay more. In general, if you pay around $5,000 for the generator equipment, the whole project - including installation - will cost around $10,000. 

Like stated earlier, most 20kW generators are air-cooled, however, if you choose a liquid-cooled generator, the cost of the equipment and installation can start anywhere in the mid-teens to more than $20,000.

Why Should I Get A 20kW Generator? 

Over 70% of generator installations consist of 20kW air-cooled generators, so they’re clearly a popular choice. As noted earlier, if your home is 2500 square feet or less and has gas heat and hot water, the generator can power all of your home's amenities.

20kW air-cooled generators are also a good choice if you have a large home and need a partial house generator to power essential circuits.

If your house is larger than 2500 heat and is all-electric powered and you need a whole house generator, it’s better to opt for a liquid-cooled generator, but be prepared for greater costs. 

What’s The Difference Between A “Whole House Generator” And A “Partial House Generator”?

There’s a very obvious difference between the two, as a “whole house generator” will power everything in your home as it’s connected to all house circuits. On the other hand, a “partial house generator” is only connected to a few essential circuits.

This can be an effective way to save money by only providing power to the most important electrical circuits such as refrigerators and lights. 

Will A 20kW Generator Power A Heat Pump? 

If you are using a portable generator, they are not generally designed to run major systems like heat pumps. Heat pumps vary in size, and the bigger they are, the more amps they need to run the system.

However, some portable generators are capable of powering moderately-sized heat pump systems depending on the wattages of both the portable generator and your system.

If you have a home standby generator, they are best suited for running a heat pump system.

On average, heat pump systems usually require around 15kW or more to work. If you are using a 20kW generator, you need to consider the starting watts and consumption watts of the other appliances you need to power. 

Is It Cheaper To Run A Propane Or Gas Generator? 

In general, it’s cheaper to run a propane generator rather than a natural gas generator, however, fuel is usually cheaper for natural gas units. Some people prefer the cheaper costs of the unit instead, so will opt for a propane generator. 

On average, a generator will use between 2 to 3 pounds of propane per hour, so a generator will run for around 5 hours on 20 pounds of propane. 

I'm an environment and energy blogger who teaches outdoor and energy enthusiasts how to be better informed when it comes to purchasing or maintaining a generator, solar panel system, or anything else related to your energy needs.