For many buyers, 4,000 watts is the sweet spot for power generation. These are the largest generators available with fully enclosed engines, keeping them quiet. They’re also the lightest generators available with wheels and handles, making them easy to move around. Add in enough power for most major appliances, and they become a great option for everything from tailgating to home backup power. What exactly can you power with these devices, and what appliances need more power? Here’s a breakdown of different use cases, as well as the user experience you can expect from these generators.
How Much Power Can I Actually Get from a 4,000 Watt Generator?
Technically, you can get a full 4,000 watts from the generator. However, when you consider real world factors for output, noise and reliability, the amount of usable power is much lower.
Most generators advertise their surge output. This is the maximum power the generator can make over a short period of time, usually no more than one minute. This helps the generator keep up with reactive loads: when you turn on an appliance with an electric motor, it needs two to three times more power to start than it needs to keep running. Typically, sustained power is 20% less than surge power. That means you can maintain a load of 3,200 watts with a 4,000 watt generator.
Using a 4,000 Watt Dual Fuel Generator
Are you looking at dual fuel generators? LPG is less energy dense than gasoline, so the engine makes about 10% less power running on propane than it does on unleaded. If you have a generator that makes 4,000 watts of surge power and 3,200 watts of sustained power on gasoline, you can expect output to drop to 3,600 watts of surge power and 2,880 watts of sustained power on LPG.
Of course, you don’t want to run your generator at full capacity all the time. Keeping the engine at its limit accelerates wear. Manufacturers generally recommend keeping electrical loads at 90% of the generator’s capacity. Now, you have 2,880 watts of reliable power from a gas-powered generator, or about 2,600 watts on a propane-powered generator. Since surge loads are temporary, it doesn’t hurt the generator to have spikes that are near its load capacity.
How Much Noise Does 4000 Watt Generator Make?
What about noise? There’s no standard way to measure the loudness of generators. Manufacturers generally rate noise in decibels measured from either 10 or 30 feet away, and either 25% or 50% load. The decibel scale is logarithmic, so a 10 dB difference is a perceived doubling of sound. The difference between a generator running at half load and full load is usually at least 5 dB. In other words, if you don’t want to annoy your neighbors and yourself, smaller loads are better.
The same goes for fuel usage: runtime quotes might be for 25% or 50% load. Run the generator at full capacity, and you’ll need to refuel two to four times as often. Virtually all generators in this size class have a smart throttle, adjusting output automatically, depending on load. This lets the generator keep up with demand, while minimizing noise and fuel consumption.
Connecting Your Devices to Maximize Power Access
How do you get all 4,000 watts to your appliances? In most cases, you need to spread out loads across multiple outlets. Generators use standard NEMA sockets. The second number in a NEMA outlet’s name is its maximum supported amperage. Multiplying amps by volts gives you the maximum number of watts supported by the socket. For example, a standard household 120 volt outlet is a NEMA 5-15R. It has a current limit of 15 amps and 125 volts. That’s equal to 1,875 watts.
125 volt sockets are usually wired in duplex, so two sockets share the same circuit, and the same current limit. A pair of NEMA 5-20R outlets wired in duplex support up to 20 amps, which is 2,500 watts. Some manufacturers use circuits with smaller amp limits, but those are rarely seen in generators this size.
TT-30 and L5-30 sockets support 30 amps, or 3,250 watts. NEMA 14-50R outlets support up to 50 amps, or 6,250 watts. That means you can access the full power of the generator from a 14-50R outlet, but you’ll need to use a TT-30 or L5-30 outlet in combination with other outlets to get full power from your generator.
If you want to use your generator for backup power using home wiring, you are legally required to install a transfer switch. This device separates your home from the power grid. Without one, your generator could send power to neighboring electric lines, which can electrocute line workers.
What can you power with one of these generators? Here are a few common was people use their generators for power, and the amount of power drawn by appliances in these use cases.
Lights and Electronics
In the past, estimating power from lights was easy, since the wattage was written on the bulb. To help shoppers find replacements using new lighting technologies, manufacturers started rating bulbs based on their equivalent light output compared to incandescent bulbs. A 60 watt equivalent LED bulb doesn’t actually use 60 watts. Instead, it usually draws between 8 and 10 watts. The actual power draw should be labeled on the top or neck of the bulb.
You need to use an inverter generator to power electronics. An inverter turns the AC current from the alternator into direct current, then converts it back into alternating current. This separation irons out power and voltage fluctuations that can burn out sensitive circuitry.
LCD TVs under 50 inches use between 50 and 100 watts, while the largest screens use up to 200 watts. A Blu-Ray player needs 15 watts, while game consoles use between 40 and 150 watts. Most satellite receivers, streaming boxes and cable boxes use between 15 and 30 watts.
A laptop uses between 25 and 85 watts when it’s on and charging. Desktops need between 400 and 800 watts, although loads over 1,000 watts are possible with gaming computers. Laser printers need as much as 2,000 watts to start, while the heating element draws 500 watts while it’s on. Ink jet printers only need between 25 and 75 watts.
Charging small electronic devices, including tablets, phones and drones, uses less than 10 watts. If your generator has USB ports, you can use them for more efficient DC-to-DC charging.
Cooking Appliances for Home Backup, Tailgating and Camping
A drip coffee maker uses between 600 and 1,200 watts of continuous power, depending on its size. Pod-based coffee makers are reactive loads, due to the pumps needed to draw in and push water through the system. These loads can be as high as 1,500 watts. Slow cookers draw about 250 watts, while other heating appliances, including toasters and hot plates, use between 750 and 1,500 watts.
On average, a microwave’s power draw is 50% to 60% higher than it’s cooking wattage. If you use a 1,000 watt oven, it needs at least 1,600 watts of electrical power.
A household blender or hand mixer uses up to 1,200 watts to start, and between 400 and 600 watts to run. Large commercial mixers and blenders have starting load spikes over 2,000 watts.
RV Shore Power
A 15,000 BTU air conditioner requires between 3,200 and 3,500 watts to start, and 1,200 to 1,700 watts to run. This is the largest unit you’re likely to see in an RV. However, the biggest motor coaches usually have two units, which are too much for a single 4,000 watt generator. Power consumption scales almost evenly, so a 7,000 watt BTU unit uses just over half as much power.
A 6 gallon electric water heater uses around 1,450 watts. RV refrigerators are far more efficient than household versions. They use 500 to 600 watts to start the compressor, and about 200 watts to run.
A 1 HP compressor uses around 2,000 watts of electricity. Most large tools, including table saws, drill presses and belt sanders, need up to 1,800 watts of power. Angle grinders are some of the most power hungry hand tools, requiring an average of 900 watts of continuous power. Other hand tools have peak loads between 800 and 1,200 watts. A standard shop vac uses 1,500 watts.
Charging a single tool battery uses between 25 and 100 watts of electricity. The electronics in lithium ion battery chargers are sensitive to power fluctuations, so you should only use them with inverter generators.
Home Backup Power
You can’t power a furnace fan, central air conditioner or electric water heater with a generator this size. However, you can power a small window air conditioner. On average, 10 BTUs of cooling power uses one watt. Most units range between 5,000 to 15,000 BTUs, which equates to 500-1,500 watts of electricity.
An electric stove uses between 1,300 and 1,800 watts per burner, while ovens use anywhere from 1,000 to 5,000 watts, depending on their size, efficiency and temperature settings. A dishwasher uses up to 2,400 watts to start, and 1,500 watts to run. A refrigerator uses 2,200 watts to start and between 500 and 750 watts to run. You can expect similar current draw from a full size front door or chest freezer. In other words, you can do some basic cooking with one of these generators, but you can’t bake or do major cleaning and keep your refrigerator running.
A clothes washer needs 2,300 watts to start and between 500 and 1,200 watts to run. An electric clothes dryer needs too much power for a 4,000 watt generator, but you can use one to run a gas dryer. It needs around 1,800 watts to start and 700 watts to run the drum motor and fan.
A ½ HP sump pump or garage door opener needs 2,100 watts to start and 1,050 watts to run.