FAQ: What Will a 4000 Watt Generator Run?

In general, this type of machine will run almost all household appliances, power tools, RV and camping appliances, including:

1. Small window AC unit – 1,200 watts
2. Fridge with a freezer – 700 watts
3. Small well pump (1/2 HP) – 1,000 watts
4. Washing machine – 1,150 watts
5. Coffee maker – 1,000 watts
6. Microwave oven – 1,000 watts
7. Dishwasher – 1,500 watts
8. Pressure cooker – 700 watts
9. Espresso machine – 1,300 watts
10. Toaster – 850 watts
11. Ceiling fan – 60 watts
12. Vacuum cleaner – 200 watts
13. TV – 85 watts
14. Sump pump (1/2 HP) – 1,050 watts
15. Small heating system – 500 watts
16. Laptop – 50 watts
17. VCR / DVD Player – 100 watts
18. Smaller electric appliances – 400 watts
19. A couple of power tools – 800 watts
20. Medium radiant heater – 1,800 watts
21. Bench grinder – 1,400 watts
22. Hammer drill – 1,000 watts
23. Radial arm saw – 2,000 watts
24. Electric water heater – 4,000 watts
25. Steam iron – 2,200 watts

To learn, whether you can run all these at the same time you need to know the power consumption of each appliance in your home.

There are some universal rules and precautions you need to follow when you want to run your generator safely.

The best document on this topic is the OSHA Fact Sheet: Using Portable Generators Safely and here is a quick summary:

• Never attach a generator directly to the electrical system of a structure (home, office, trailer, etc.) unless a qualified electrician has properly installed the generator with a transfer switch.
• Always plug electrical appliances directly into the generator using the manufacturer’s supplied cords or extension cords that are grounded (3-pronged). Inspect the cords to make sure they are fully intact and not damaged, cut or abraded.
• Use ground fault circuit interrupters (GFCIs), especially where electrical equipment is used in or around wet or damp locations. GFCIs shut off power when an electrical current is detected outside normal paths.
• Never use a generator indoors or in enclosed spaces such as garages, crawl spaces, and basements. NOTE: Open windows and doors may NOT prevent CO from building up when a generator is located in an enclosed space.
• If you or others show symptoms of CO poisoning—dizziness, headaches, nausea, tiredness – get to fresh air immediately and seek medical attention.
• Keep fuel containers away from flame producing and heat generating devices (such as the generator itself, water heaters, cigarettes, lighters, and matches).

In general, a 4,000 running watts generator doesn’t provide enough power to run a heat pump or electric furnace. However, answering this question is really hard without knowing the exact running and starting watts required by your electric appliance.

Please, contact the manufacturer of your pump or furnace to learn more info on its wattage requirements.

Sadly, there is not a single answer to this question. To learn, whether you can run your welder on a 4,000-watt portable generator you need to know the power requirements of your welder (see the data tag or user manual you got to your welder).

However, based on the information we were able to learn, the best option is to get a special generator that has been manufactured for welding purposes such as LIFAN AXQ-200A to be able to harness the full potential of your welder.

You can shop for some good options on Home Depot or Amazon.com

In general, a 4,000 – 4,300 running watts generator should provide enough power to run a small air compressor without any issues. However, answering this question is really hard without knowing the exact running and starting watts required by your air compressor.

I have found rough estimates for different types of compressors:

• 1/2 Horse Power – It takes 975 running watts and 1,600 starting watts.
• 1 Horse Power – It takes 1,600 running watts and 4,500 starting watts.

As you can see in the estimates above, the issue is not running watts but starting watts. To get the precise numbers, you will need to find the voltage, amperage, and horsepower information on the info-plate of your compressor.

Then, all it takes to learn required wattage is to apply this equation:

Watts (W or kW) = Volts (V) x Amps (A)

In general, a 4,000 – 4,300 running watts generator should provide enough power to run a small RV AC unit (11000 BTU) without any issues. However, answering this question is really hard without knowing the exact running and starting watts required by your AC unit.

I have found rough estimates for different types of RV air conditioning units:

• 11000 BTU – It takes 1,050 running watts and 1,600 starting watts.
• 13000 BTU – It takes 1,800 running watts and 2,800 starting watts.
• 15000 BTU – It takes 2,000 running watts and 3,300 starting watts.

As you can see in the estimates above, the issue is not running watts but starting watts. To get the precise numbers, you will need to find the voltage and amperage information on the info-plate of your RV AC unit.

Then, all it takes to learn required wattage is to apply this equation:

Watts (W or kW) = Volts (V) x Amps (A)

In general, a 4,000 generator should provide enough power to run a circular saw. A rough estimate of the power requirements of a heavy-duty 7.25″ circular saw is as follows:

• 1,400 running watts
• 2,300 starting watts

So, as long as your generator offers at least 2,500 starting watts (we recommend getting slightly more power than needed), you should be able to run your machine on this type of generator.

A rough estimate of the energy requirements of a space heater is as follows:

• 1,800 running watts
• 1,800 starting watts

As you can see, you can easily run your space heater with a 4,000 – 4,300 running watts generator. Just don’t forget to double-check the name tag on your appliance to learn the precise wattage requirements.

In general, a common microwave needs around 1000 watts to operate. A 4000-watt generator has at least 4,000 running and 4300 starting watts so you can run your microwave pretty easily.

Just don’t forget to check the nameplate on your appliance to learn the precise wattage requirements.

In general, a refrigerator takes around 1200 surge watts at the beginning while the compressor kicks in and then it gradually drops down to around 200 running watts. As you can see, each and every generator in this article could run a mid-sized refrigerator.

If you choose at least a 2000 starting watts inverter generator (Yamaha EF2000iSv2, WEN 56200i, or Generac GP2200i), you can power any modern refrigerator with a freezer easily.

Most fridges require about 800 – 1200 starting watts and 4000 watts is more than enough to power them safely.

Also, if your generator has a high total harmonic distortion, your fridge (especially if you have a modern type) may get damaged (that is why we recommend getting an inverter type of generator).

The size of a generator depends on the type of fridge you want to power:

• While modern appliances have much lower power consumption (around 300 – 400 watts), even while the compressor starts to kick in, the older types of fridges are going to need a bigger power supply (around 300 – 1,200 watts).
• Another aspect that will affect the required size of your generator is whether your fridge also comes with a freezer. In such a case it will require even more power (add 80 – 100 watts to those numbers mentioned above).

Learn more about the power consumption of different types of refrigerators in our guide FAQ: What Size Generator Do I Need to Run a Refrigerator?

Definitely. As long as your generator is an inverter with a low total harmonic distortion, then you can run your TV safely on a 4,000-watt generator.

Here are some rough estimates of wattage requirements of various TVs:

• Tube type – It takes 300 running watts and 300 starting watts.
• Flat Screen (20”) – It takes 120 running watts and 120 starting watts.
• Flat Screen (46″) –  It takes 190 running watts and 190 starting watts.

As you can see, you will have enough spare power to run your DVD player which takes approximately 350 running and 350 starting watts as well.

Usually, a 4,000 – 4,300 running watts generator should provide enough power to run a small sump pump without any issues. However, answering this question is really hard without knowing the exact running and starting watts required by your pump.

I have found rough estimates for different types of sump pumps:

• 1/3 Horse Power – It takes 800 running watts and 1,300 starting watts.
• 1/2 Horse Power – It takes 1,050 running watts and 2,150 starting watts.

As you can see in the estimates above, the issue is not running watts but starting watts. To get the precise numbers, you will need to find the voltage, amperage, and horsepower information on the info-plate of your pump.

Then, all it takes to learn required wattage is to apply this equation:

Watts (W or kW) = Volts (V) x Amps (A)

Just keep in mind that your sump pump will probably require a 240V outlet on your generator. 

In general, a 4,000 – 4,300 running watts generator should provide enough power to run a small well pump without any issues. However, answering this question is really hard without knowing the exact running and starting watts required by your water pump.

I have found rough estimates for different types of pumps:

• 1/3 Horse Power – It takes 750 running watts and 1,500 starting watts.
• 1/2 Horse Power – It takes 1,000 running watts and 2,100 starting watts.
• 3/4 Horse Power – It takes 1,500 running watts and 3,000 starting watts.
• 1 Horse Power – It takes 2,000 running watts and 4,000 starting watts.
• 1 & 1/2 Horse Power – It takes 2,500 running watts and 5,000 starting watts.

As you can see in the estimates above, the issue is not running watts but starting watts. To get the precise numbers, you will need to find the voltage, amperage, and horsepower information on the info-plate of your pump.

Then, all it takes to learn required wattage is to apply this equation:

Watts (W or kW) = Volts (V) x Amps (A)

We have serious doubts that a 4000-watt generator would provide enough power to run a central AC unit. We would rather go for a very small emergency window AC unit as 4,000-watt generators may have too little starting power.

However, the answer to this question really depends on the number of running and starting watts your AC unit requires.

Obviously, these numbers vary from one unit to another and are based on the cooling ability of individual models and brands. That is why you need to look for the following data on the name tag of your central AC unit:

1. LRA (Locked Rotor Amps) – This number represents the current you can expect under starting conditions when you apply full voltage.
2. RLA (Rated Load Amps) – This number represents the maximum current a compressor should draw under any operating conditions.
3. FLA (Full Load Amps) – This number represents the same as the Rated Load Amps.

You need to take into consideration the amps for both the compressor and the fan unit. To determine, if your 4,000-watt generator can run a central AC, please consult its manufacturer or a professional electrician.

Keep in mind that a typical central air unit runs on 208/240 volts and is often permanently mounted and hardwired into the electrical system of your house. That is why to safely run this electronic appliance you need to connect your generator through a transfer switch.

Actually, you should always connect your generator through a transfer switch if you don’t want to damage your appliances or endanger people who may be working on electric lines in your neighborhood.

Usually, a 4000 watt gasoline generator has a 4-stroke engine. If this is the case, you will need to use either SAE 30 (if you live in a warmer climate) or a SAE 10W-30 if you are going to use it in a colder climate (do not forget to double-check with your owner´s manual).

However, there are several things you need to consider while choosing the oil for your machine:

• Whether you got a 2-stroke or a 4-stroke engine
• Starting and operating temperatures
• Type of fuel your machine runs on
• Certifications and classifications of the oil
• Reputation of the brand and company producing the oil

If you need to learn more information on how to choose the best oil for your generator, then consult our guide that is available right here. We provide you also with a list of best brands in various categories of oil.

In general, a 4,000-watt generator provides approximately 33.3 amps, in case of 120 volts or 16.6 amps in case of 240 volts. To learn more, you should check out the owner´s manual to the machine you want to buy.

Actually, identifying how many amps there are in a 4000 running watt generator is a very simple process. All you have to do is to apply the following formula:

Amps (A) = Watts (W or kW) / Volts (V)

You need to divide the wattage by the voltage. So, in this case, you need to divide 4000 by 120 or 240 to get the correct numbers. In case you are looking for power requirements of household appliances, here is our helpful list of over 100+ products and their power needs. 

Here is our handy cheat sheet:

• 500 Watts, 120 V = 4.2 A, 240 V = 2.1 A
• 1000 Watts, 120 V = 8.3 A, 240 V = 4.2 A
• 2000 Watts, 120 V = 16.7 A, 240 V = 8.3 A
• 3000 Watts, 120 V = 25.0 A, 240 V = 12.5 A
• 4000 Watts, 120 V = 33.3 A, 240 V = 16.7 A
• 5000 Watts, 120 V = 41.7 A, 240 V = 20.8 A
• 6000 Watts, 120 V = 50.0 A, 240 V = 25.0 A
• 7000 Watts, 120 V = 58.3 A, 240 V = 29.2 A
• 8000 Watts, 120 V = 66.7 A, 240 V = 33.3 A
• 9000 Watts, 120 V = 75.0 A, 240 V = 37.5 A
• 10000 Watts, 120 V = 83.3 A, 240 V = 41.7 A
• 12000 Watts, 120 V = 100.0 A, 240 V = 50.0 A
• 14000 Watts, 120 V = 116.7 A, 240 V = 58.3 A
• 16000 Watts, 120 V = 133.3 A, 240 V = 66.7 A

This question doesn’t have an universal answer as each generator has unique fuel consumption and capacity of the fuel tank. From our experience an average 4,000 watt generator runs for approximately 10.2 hours on a 50% load.

This number is a median that we got after looking at the run time of over 13 generators that provide around 4,000 running watts.

Here are some examples:

• A-IPOWER SUA5000 – 4,250 running watts – 9 hr on a 50% load (4.0 gal)
• Westinghouse iGen4500 – 3,700 running watts – 18 hr on a 25% load (3.4 gal)
• Pulsar PG5250 – 4,250 running watts – 8 hr on a 50% load (4.0 gal)
• Champion 4000 – 3,500 running watts – 17 hr on a 25% load (2.9 gal)
• DuroMax XP4400E – 3,500 running watts – 11.4 hr on a 50% load (3.9 gal)
• Yamaha EF4500iSE – 4,000 running watts – 15.2 hr on a 25% load (4.5 gal)
• DEWALT DXGNR4000 – 4,000 running watts – 10.5 hr on a 50% load (3.4 gal)
• LIFAN ESI4000iER-EFI – 3,800 running watts – 12 hr on a 50% load (3.5 gal)
• DuroMax XP5500EH – 4,500 running watts – 8 hr on a 50% load (4.0 gal) 

One of the most notable advantages of inverter generators is that they’re perfect for powering small devices, such as computers, televisions, and smartphones.

If you prioritize things like fuel efficiency, quietness, portability, and the ability to safely power sensitive electronics, you really can’t go wrong with an inverter generator.

While some traditional generators can produce upwards of 17,000 watts, inverter generators don’t usually reach figures higher than around 7,000.

PROS OF AN INVERTER GENERATOR:

• Produces power with significantly lower THD
• Lighter and smaller
• More energy efficient than traditional generators
• Much lower fuel consumption
• Parallel capability
• Safe for sensitive electronics like laptops or mobile phones
• Quieter than traditional generators

CONS OF AN INVERTER GENERATOR:

• Significantly more expensive than traditional generators
• Lower power output – limited wattage range
• Costly repairs and servicing
• Limited fuel options

For a comprehensive overview of inverter generators and how they work, read our guide here: What Is an Inverter Generator & How Does It Work? (Pros + Cons Included)

There are several features you can consider while shopping for the best generator for your home. Our team here at Generatorist recommends the following:

1. At least 1 alternative fuel source if gasoline is not available
2. Electric start with manual recoil backup for convenient use by anyone
3. Included maintenance-free electric battery with a trickle charger
4. Built-in inverter or automatic voltage regulation
5. Automatic idle control for reduced fuel consumption
6. Durable frame and steel fuel tank
7. Fuel gauge and low-oil shutoff
8. Manual fuel-shutoff switch/valve
9. Longer run time
10. OHV (overhead valve) engine
11. Spark arrestor
12. Multiple types of outlets with covers
13. At least one outlet for higher wattage items (30 amp)
14. Folding handles with a wheel kit

To read more about how to pick the best generator for your home, check out our helpful guide linked above. 

We recommend you consider the following features:

1. Fuel Type – For job contractors, we recommend generators that are running on diesel as this type of fuel is more frequently used in other machines that are usually present on the job site. This way, your fuel management will be much easier.
2. Long run time – The worst thing that can happen on a job-site is a downtime as it leads to profit loss. Every refueling takes your machine out of service for some time. Therefore, it is vital to get a generator that can run for a whole shift without the need to refuel. This way, you can do the refueling with basic maintenance after the work shift is over.
3. Large gas tank – Although a large gas tank will diminish the portability of your generator, it will enable you to run it for a longer period of time without the need to refuel.
4. Automatic idle control – The automatic idle control (also known as Eco Throttle or Smart Throttle) can save you a lot of fuel costs and can reduce the noise of your generator. It automatically adapts the rotations of your engine in relation to the actual load. If your generator runs idle, this system can significantly reduce the number of rotations per minute.

To discover more features you should look for in your next generator, read our tips in this article here: Choosing The Best Generator for Contractors

There is no single answer to this question. Actually, there are several features of your 4000 watt generator you need to consider while choosing your transfer switch.

We are going to cover this topic soon but in the meantime, feel free to read this comprehensive guide from Electric Generators Direct: How to Pick the Perfect Manual Transfer Switch.

If you are looking for an RV generator, our advice is to choose a machine that is powerful but still quiet. Ideally, go for an inverter.

There are only two inverters in this category of generators that are also quiet at the same time:

1. Yamaha EF4500iSE
2. Wanco WI4300

There is also one RV ready generator in this category – the Pulsar PG5250B. If you want to get any other unit from this list, then you need to get a necessary set of adapters (also called dogbones) to easily connect your RV through either a 20 or a 30 amp outlets.

So pick a generator that fits your needs the most and if it is not RV ready, don’t forget to get the correct adapter.

Finding reliable information on the “noisiness” of generators is a tough job to do. However, based on our findings, we can list the following machines as “quietest”:

1. Yamaha EF4500iSE
2. Wanco WI4300

In general, if you want a portable generator that is powerful but also quiet at the same time, then go for an inverter. Sadly, these machines are much more expensive than regular generators.

If you are looking for a 4,000 -4,300 running watts generator that offers the most comfortable electric start, then we have only two options that stand out:

1. Yamaha EF4500iSE (4,000 running / 4,500 starting watts)
2. Wanco WI4300 (4,000 running / 4,300 starting watts)

Both machines are inverters and provide clean power. So choose one according to the maximum starting and running watts you require.

There are two 4,000 generators that can run on propane as well:

• Pulsar PG5250B (dual fuel – 4250 running watts generator)
• QuipAll 5250DF (dual fuel – 4,000 running watts generator)

Both of these machines provide a good quality-vs-price ratio.

If you are looking for the best inverter generator that provides 4,000 – 4,300 running watts, then there are two options for you to choose from.

Based on our research, the best inverters in this category are:

1. Yamaha EF4500iSE (4,000 running / 4,500 starting watts)
2. Wanco WI4300 (4,000 running / 4,300 starting watts)

Just keep in mind that although inverters are running quietly, they are on the more expensive side.