How To Run A Well Pump With A Portable Generator?

Like many others, if you also rely on your own water supply system in your home, you probably know about well pumps. A well pump provides an uninterrupted supply of clean water as per user needs through a continuous electricity supply.

Since an uninterrupted electricity supply is mandatory to run the pump, a power outage can cause you no water in your home. However, to run your well pump during power outage, you can go for a generator as an alternative power source.

Simply get a generator based on the HP or horsepower of your well pump and start getting water in all conditions. However, if you don’t know How To Run A Well Pump With A Portable Generator, follow this article for reliable guidance.

Will A Portable Generator Run A Well Pump?

Unfortunately, long and short-term power outages are happening more frequently than ever before. And no electricity means you can’t use any electrical device that requires an uninterrupted power supply.

So if you have a well pump and are suffering from annoying power outage issues, then you can use a generator. You can use all types of generators, including a portable generator, to run a well pump.

Will A Portable Generator Run A Well Pump

Using a portable generator to power well pump would be the most reliable way to ensure an uninterrupted water supply through your pump. The generator will provide an adequate continuous electricity supply during power outages to keep the water supply running at home or your desired places.

What Size Generator Do You Need To Run Well Pump?

What size generator you need to run a well pump depends on several aspects because the wattage varies with the brand and product. First, you have to find out the required wattage through the following equation:

What Size Generator Do You Need To Run Well Pump

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

Once you’ve determined the accurate watt of your well pump, now multiply the watt by 2. You must multiply the wattage by two because all motor-driven items require more or double stating watts than running.

Here we’ve included a chart that shows what starting and running watt is required for different horsepower well pumps. Have a look-

Well Pump Size Starting Watt Running Watt
1/3 HP Well Pump 1500-watt 750-watt
1/2 HP Well Pump 2000-watt 900-watt
3/4 HP Well Pump 3000-watt 1500-watt
1 HP Well Pump 4000-watt 2000-watt
1.5 HP Well Pump 5000-Watt 2500-watt
2 HP Well Pump 7500-Watt 3750-Watt
3 HP Well Pump 10000-Watt 5000-Watt

The table shows an estimate of the starting and running watts for conventional well pumps. This is an estimated cart only, and you can check your pump’s manual book for an accurate idea.

How To Run A Well Pump With A Portable Generator

Although it seems complicated to run a well pump with a portable generator, it’s not that difficult. Hooking a well pump with a generator is relatively easy and by following the below steps you can do it by yourself. Here are the steps:

How To Run A Well Pump With A Portable Generator

Step – 1:  Select the Right Size Generator

First, you have to select a generator based on the HP of your well pump. 1 HP is the most standard well pump that most users use, and it requires a  3-4 KW generator to start and run the pump. Get a generator based on its HP, which delivers the required starting and running watt.

Step – 2:  Check and Fuel the Generator

After selecting the right generator for your well pump, now it’s time to inspect the generator. You have to ensure everything in your generator is working well and don’t forget to check the fuel tank and air filter. Also, check the fuel level and never run the generator with a low fuel level.

Step – 3:  Place the Generator

Once your generator is all set to use, now you have to place it in a perfect place. You cannot just place your generator anywhere you want or indoors as it emits toxic and harmful gases. Simply place or install a generator where the place has enough ventilation.

Step – 4:  Hook up the Generator With Well Pump

Here is the most important part comes, and you can hook up the generator with a well pump in two different ways, including:

  1. Using a Transfer Switch
  2. Directly Plug the Pump With Generator

We are going to discuss how these two methods can be applied; follow the below section:

1. Using a Transfer Switch

Using a transfer switch is one of the safest ways to connect and run your well pump with a generator. A transfer switch is a much better option than a separate circuit breaker, reducing all types of possible impacts. Here we’ll show how to use a transfer switch to power the pump with a generator; follow the below steps:

  • When the power outage happens, turn off the main breaker from the circuit breaker. Also, turn off all the circuit brakes of the transfer switch as well.
  • Now connect your generator’s cord to the transfer switch or the inlet box and turn on the generator.
  • Once the generator is started, now flip or turn on the main breaker of the transfer switch. After that turn on the well pump circuit, and you’ll start getting water during a power outage.

Make sure you have installed the right transfer switch in your home that will match your generator’s load. And most of the time, a 30 Amp power transfer switch is the perfect one to run a generator that a standard well pump requires.

2. Directly Plug the Pump With Generator

If you don’t want to use a transfer switch, you can go for the direct plugging method. You can easily plug your well pump into your generator’s outlets. Know how to connect your well pump with generator directly by following the below steps:

  • Disconnect the pump wire from the main electric panel during a power outage.
  • After disconnecting the pump wire, use a plug (30Amp or as your pump and generator require) to connect the wire with the generator.
  • Once you connect the pump wire with the generator through a plug, now turn on the generator. Now your pump will start providing water.

When it’s about directly connecting the pump wire with the generator, you have to use a plug according to requirements. If you’re using 1/2 HP or above well pump, it means it’s 230 volts. 230 volts require a 30 Amp plug and most of the generators have a 30 Amp plugging system.

So get a good quality 30Amp plug and that will efficiently run the well pump after connecting it to the generator. If you wish to use this method to run your pump with your generator, check out this video for more assistance.

Can A Generator Damage A Well Pump?

A generator can work as a double-edged sword for a well pump by providing advantages and disadvantages. The fact is using a generator can damage your well pump, and here we’ll show how a generator can damage a well pump. Have a look-

Can A Generator Damage A Well Pump

Generator Size:

A generator can damage your well pump if you’re using a less powerful generator than the pump requires running. Always determine what amount of watt your pump requires for starting and running, and then plug it with the appropriate generator.

Not Using a Transfer Switch:

A transfer switch is mandatory to connect heavy equipment like a well pump with a generator. Since transfer switches overlap all impacts, not using them can impact your well pump and even damage it.

Defective Generator:

A defective generator can damage not only the pump but also cause serious issues. This type of generator can cause fuel leaks and also can produce toxic carbon monoxide poisoning.

Using Low-Quality or Dirty Fuel:

Using low-quality or dirty fuel can decrease the fuel’s stability and cause fuel to be useless, which will impact your pump. Moreover, low-quality fuel can cause power loss, higher fuel consumption, increased emissions, and detonation wear.


Overload, overheating, over-speed can significantly impact a generator and the water pump as well. While you’re running the pump and generator continuously, try to give them a break to reduce all impacts.

Final Thoughts

Monsoon storms, a bright flash of lightning, a loud clap of thunder can commonly cause power outage issues. And the power outage causes inconveniences in several aspects, especially when you use a private water supply system. It’s like no electricity means no water supply.

However, using a generator for a well pump will ensure the required electric supply during an outage. Just get a generator based on the HP of your well pump and start getting water in any condition. Since you know how to run a well pump with a portable generator, today get a generator to run when the power goes out.

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