What Will a 15000 Watt Generator Run? – [Will It Run My AC?]

This article is all about answering your burning question about “What Will a 15000 Watt Generator Run?” How many appliances can be run simultaneously and will it run my air conditioner, well pump, heat pump, and other power-hungry appliances?

A 15000-watt generator is a perfect machine for powering heavy-duty appliances of households, RVs, or Job sites including the central air conditioner, dryer, electric water heater, heat pump, welder, sump pump, air compressor, etc.

What Will a 15000 Watt Generator Run?

Understanding Generator’s Wattages

Like other tools/appliances, the generator comes with two wattage ratings one is starting and the other is running.

Starting/surge watts: Maximum wattages a generator can produce for a short time to power up the motorized/compressor-based tools/appliances.

The purpose of surge watts is to provide initial push/inertia to the appliance, the rest of the work will be handled by the running/rated watts. Starting watts will always be higher compared to running watts.

Running/rated watts: Maximum wattages a machine can produce for a longer time to run the appliances in stable conditions.

Running watts is as important as starting watts; however, you will find them a bit lower compared to the starting watts.

What Appliances Can a 15000 Watt Generator Run?

ApplianceRunning WattageStarting Watts
Deep Freezer5001500
Food Processor4000
Curling Iron15000
Central AC 40.000 BTU60007500
Electric Drill 1/2 inch 5.4 Amps600900
Ceiling Fan100300
Furnace Fan 1/3 HP7001400
Table Saw 10 inch20002800
Electric Water Heater 4 kW40000
Airless Sprayer6001200
Window AC 12.000 BTU15002300
Miter Saw 10 inch18002500
Belt Sander12002400
Toaster Oven12000
Garade Door Opener 1/2 HP9002400
Iron (Clothes)15000
Sump Pump 1/3 HP8001300
Electric Stove 2kW20000
Light LED Bulb 10 W100
Window AC 5.000 BTU600900
Planer/Jointer 6 inch18002500
Electric Grill 1.6 kW16000
Iron (Waffles)12000
Security System5000
Sump Pump 1/2 HP10502200
Halogen Work Light 300 W3000
Window AC 15.000 BTU19002900
Vacuum Cleaner 12 Amps14402500
RV Air Conditioner 10.000 BTU12002000
Coffee Maker10000
Humidifier 13 gal.1750
Microwave Oven 600 W6000
Box Fan 20″200350
Air Compressor 1 HP16004500
RV Air Conditioner 7.000 BTU9001700
Clothes Dryer – Electric50007000
RV Air Conditioner 13.500 BTU16002500
Well Pump 1/2 HP10002100

Recommended Read: What will a 12000-watt generator run?

Will a 15000 Watt Generator Run a Whole House?

Yes, a 15kw machine is not only enough to run the standard appliance of 100 – 2000 watts but also draws enough power to even run most of the power-hungry appliances like central air conditioners, electric water heaters, heavy-duty welders, dryers, etc. Even you can run two or three of them simultaneously.

The bottom line is a 15000w generator is more than enough for even a medium to large household, however, if you want to run a bunch of heavy-duty tools/appliances at the same time, you should have to determine your power needs first before making a buying decision. Follow this section of the article to calculate your power requirements in instant.

How Many Appliance I Can Simultaneously With a 15KW Machine?

Though a 15000w machine is capable of running most of the standard appliances simultaneously, still if you are going to run some of the heavy-duty tools/appliances at the same time make sure to read their power ratings first.

E.g. If you have plugged 5 appliances of 2.8 – 2.9kw you will not have access to plug another one,

The bottom line is you don’t have to overload the machine, however, within the limit of 0 – 15000 watts, you can plug as many appliances/tools as you want.


  1. We encourage our readers to keep a margin of 10 – 15% load so that the machine can run more breathily. Pulling 100% load from the machine will not only increases the fuel cost but also maintenance and repair cost down the road.
  2. Always select a unit with 200 – 300 extra wattages so that the line losses should be easily tackled, also you will have a decent room even after leaving the margin of 10 – 15% load.

 Determining the Power Requirements:

  • List the appliances with their starting and running wattages, you can find the power rating from the energy labeling. If you found the power rating in amps make sure to convert them in the wattages with the help of Ohm’s law.

Ohm’s Law: W (watts or kilowatts) = Amps (amperes) X Volts (V)

E.g. an appliance consumes 24 running and 28 starting watts at the voltage of 240V

W (watts or kilowatts) = Amps (amperes) X Volts (V)

Running watts: 24 X 240 = 5760 watts

Starting watts: 28 X 240 = 6720

NOTE: If you can comfortably do the calculations in amps then you don’t have to do conversions.

  • Sum up the starting and running wattages of the appliances and keep them in a separate column.
  • Compare the calculated running and starting watts with the machine you are going to own.

Practical Example:

AppliancesStarting WattsRunning Watts
Refrigerator1200 Watts200 Watts
Dishwasher1500 Watts1500 Watts
Deep Freezer1300 Watts700 Watts
Washing Machine0 Watts1200 Watts
Vacuum Cleaner 12 Amps25001440
Microwave0 Watts800 Watts
Belt Sander24001200
Table Saw 10 inch2800 Watts2000 Watts
Toaster0 Watts900
Air Compressor 1 HP16004500
TOTAL13300 Watts14440 Watts

From the above calculations, we got 14440 running and 13300 starting watts, hence a premium 15kw generator could be more than enough for the above quotation.

Will a 15000 Watt Generator Run a Well Pump?

It depends on the Horsepower of the well pump you own below are some of the well pumps that can be easily run with a 15kw generator.

Sump Pump SizesStarting WattsRunning Watts
0.33 HP1,500 – 2,400 watts750 – 800 watts
0.5 HP1,800 – 3,150 watts900 – 1,050 watts
0.75 HP3,000 – 5,400 watts1,500 – 1,800 watts
1 HP4,000 – 7,200 watts2,000 – 2,400 watts
1.5 HP5,000 – 8,400 watts2,500 – 2,800 watts
2 HP7,500 – 12,000 watts3,750 – 4,000 watts

Will a 15000 Watt Generator Run a Heat Pump?

It depends on the SEER and BTUs of the heat pump you own. Below are some of the heat pumps that can be easily handled by a 15kw machine.

Heat Pump SizeBTUsWattage (14 SEER)Wattage (16 SEER)Wattage (18 SEER)Wattage (20 SEER)Wattage (22 SEER)
1 ton 12,000 BTU1,020 – 1050 W950 – 1000 W840 – 900 W820 – 880 W800 – 820 W
1.5 ton18,000 BTU1,530 – 1550 W1,400 – 1450 W1,300 – 1350W1,250 – 1280 W1,200 – 1250 W
2 ton24,000 BTU2,040 – 2100 W1,850 – 1900 W1,750 – 1800 W1,650 – 1700 W1,600 – 1650 W
2.5 ton30,000 BTU2,550 – 2600 W2,350 – 2400 W2,190 – 2200 W2,050 – 2100 W2,000 – 2050 W
3 ton36,000 BTU3,050 – 3100 W2,800 – 2900 W2,650 – 2700 W2,500 – 2550 W2,400 – 2450 W
3.5 ton42,000 BTU3,600 – 3700 W3,300 – 3350 W3,050 – 3100 W2,900 – 2950 W2,800 – 2850 W

Will a 15000-watt generator Run a Welder?

Yes, a standard welder needs about 4000 – 7000 of wattage which isn’t a big deal for a 15kw machine.

Will a 15000W Generator Run My AC?

Yes, a 15000-watt machine is powerful enough to even fire up your central air conditioner with more than 3,0000 BTUs.

How Many Amps Will a 15000-Watt Generator Run?

As per Ohm’s law, we got the following readings from my friend’s Westinghouse 15000-watt Home Backup Portable Generator.


Will a 15000 Watt Generator Run a 50 Amp RV?

Yes, a 15kw machine is more than enough to run all of the appliances of a 50 amp RV including the central air conditioner, dryers, electric water heater, etc.

Recommended Read: What size generator should I select to run my 50 amp RV?

Recommended 15000 Watt Generators


A 15kw generator is considered an ideal choice for even a big house, class “C” RV, or even a job site where you have to run some of the power-hungry tools like welders, Circular Saws, pressure washers, Air compressors, etc.

We recommend choosing a machine as per your wattage needs, don’t ever select a machine with higher wattages this will not only increase the initial cost but also the ongoing cost of fuel and maintenance.

Furthermore, you have to bear high noise levels and minimum portability. The bottom line is you should do the wattage calculation before making any buying decision.

FAQs – Frequently Asked Questions

What Size Breaker Do I Need for a 15000 Watt Generator?

As per the general thumb rule we have to use the 50 amp breakers if we have a generator between 8500 – 15000W, however, below 8.5kw we can use 30amp.

Will a Watt Generator Run a 3-ton AC Unit?

Yes, a 15kw generator is more than enough for even a 3-ton air conditioner with the lowest SEER
Note: SEER is a Seasonal Energy Efficiency Ratio developed by the industries experts.



Kashif has been a valuable asset to the electric generator industry for over 5 years. Now, As a skilled energy engineer, he’s been on the front lines of diagnosing problems, fixing broken parts, and performing routine maintenance tasks to keep generators running smoothly.

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