What Will My Kohler Standby Generator Run During a Power Outage?

By: Norwall Power Systems, an authorized KOHLER Generators dealer

The number of appliances a Kohler standby generator can power at one time depends on the generator’s output capacity and the amount of power each appliance uses. During a power outage, your first priorities are most likely personal safety and protecting your home. It may be less important for your electric stove to work than it is for your sump pump to keep the basement from flooding. As time passes and the outage continues, you may want to choose different appliances to supply with power. Knowing how much power your generator can produce will help you determine which appliances can run at the same time and which ones can wait.

Understanding Electrical Power

Electricity is measured in amps (A) and volts (V). Amperage, also known as a current, measures the amount of electrons moving within an electric circuit.  Voltage measures the amount of potential energy or force those electrons are under, which creates a current.  Electrical power, which expresses the amount of electricity being used by appliances, is measured in watts. Wattage equals your volts x the amperage. For example, an appliance plugged into a 120-volt outlet and drawing 10 amperes of current is using 1200 watts (120V x 10A). Sometimes watt is converted to kilowatt (1kW = 1,000W).

Appliances that are powered by motors are measured in volt-amps (volts x amps) instead of watts. Sometimes volt-amps is converted to kVA (1kVA = 1,000volt-amps). When calculating power for appliances that have motors, such as air conditioners and refrigerators, you have to consider the motor’s running and startup current. An appliance with a motor will typically use more power for a few seconds to turn on before dropping to a lower, steady running current. To estimate a startup current, simply multiply the running watts by three for most motors or by six for heavy duty motors.

Standby generators are rated in kilowatts to disclose the amount of power the unit is capable of producing. Kohler standby generators can produce their rated power continuously and also supply additional power to support starting motors for a short period of time. Kohler’s 14kW generators can supply 35kVA, and the 20 kW models can provide 40.5kVA to support startup currents of motors as mentioned above.

Power Requirements of Appliances

The amount of power required by an appliance varies by manufacturer. Most appliances have their electrical needs posted on product tags or in an owner’s manual.

The list below estimates the running watts and starting watts of some typical home appliances.  This list is intended to service as a basic guide; however, we recommend you consult with a professional electrician to measure the electrical requirements of your appliances.

Appliance                                  Run Watts          Start Watts

Refrigerator                               700                   2100

Freezer                                     700                   2100

Coffee Maker                             1200                 n/a

Crockpot                                   200                   n/a

Toaster Oven                              1550                 n/a

Electric Lights                            13 – 300            n/a

1000 Watt Microwave                  1200                 n/a

1 Ton Central AC                        2000                 4000

3 Ton Central AC                        4500                 9000

12,000 BTU Window AC              1700                 5100

Furnace Blower                          875                   2625

Sump Pump                               800                   2400

Well Pump                                 2000                 6000


Standby Generator Power Management

Work with your local Kohler Generator authorized dealer to choose a transfer switch and load control module for your system. During a power outage, your Kohler transfer switch will automatically transfer power from the utility grid to your generator. However, once the power is transferred some systems require load control. Load management is very important to prevent overloading your generator. By equipping your home with a load control module, you can have a smaller generator and still have access to every appliance in the house, but not all at the same time.

The load control module will manage and turn on your appliances based on how you prioritized them at time of installation and how much power is available. Good choices include the sump pump that keeps your basement dry, the refrigerator and freezer to prevent food spoilage, and the heating or cooling system. Add up the power for each appliance and remember to include the starting watts for motors.

However, you may still want to do some of your own power management to keep power flowing efficiently throughout your home. For example, if your AC unit does not start and the temperature in your home is climbing, take a look at the appliances you are running and shut some off. As you consume less power, more becomes available and the load control module will allow the AC unit to turn on.


Kohler’s generator sizing calculator is a great tool to help suggest a generator for your home, based on the amount of electricity your appliances need. Use the calculator and work with your local Kohler Generator authorized dealer to determine which generator best suits your needs.


Norwall Power Systems was established in 1997. The company specializes in selling emergency backup power generators and associated equipment.

Norwall Power Systems sells and supports many different types of power systems. They have thousands of standby generators, portable generators, marine generators, automatic transfer switches and replacement parts in stock in multiple warehouses throughout the US.


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17 Responses to “What Will My Kohler Standby Generator Run During a Power Outage?”

  1. Ed
    October 30, 2012 at 11:24 am #

    How long can a RESL 20kw run non stop?

    • CindyLee
      November 5, 2012 at 4:51 pm #

      Hey Ed, sorry for the delayed response. Our Kohler standby generators are made to run for an extended amount of time to power your home during an outage. However, there are many variables that can affect the operation of your generator, so it’s very important to follow the maintenance guidelines found in your owner’s manual.

      • John
        November 6, 2012 at 6:28 pm #

        I understand you cannot guarantee a specific amount of time but Ed has a valid question. Assume the generator has been professionally maintained and is in perfect working order. Lots those here on Long Island are facing 2 weeks without electrical power. Is a properly selected, installed and maintained generator up to running non-stop for 2-3 weeks?

        • CindyLee
          November 12, 2012 at 2:02 pm #

          Hey John, thanks for your question. Our generators pass through stringent tests to ensure that their quality meets industry standards – and our own. Since each environment is different and each generator will be tasked with a customized performance based on your home and your family’s power needs, it’s hard for us to quantify exactly how long a generator will last. That said, we have been making generators since 1920, so we know a thing or two about longevity and understand that power outages can last for extended periods of time.

          Your generator’s regular maintenance needs are similar to the steps taken to maintain your vehicle (oil changes, filter/spark plug replacement, etc.). Detailed maintenance information is included in each owner’s manual.

          Your local dealer or distributor (http://khlr.co/b9Uy) would be a great resource to provide you with more detailed information based on your specific situation. Your dealer can also provide you with a quote for a service agreement for regular maintenance as well as the cost of equipment and installation. Please let me know if you have any trouble getting in touch with someone near you.


  2. Max
    November 1, 2012 at 12:33 pm #

    Given the after effects of Sandy I imagine a number of people are thinking about creating an emergency kit. This article should be used to inform them on their emergency power back up needs.

  3. Kathleen Winfrey
    November 6, 2012 at 12:18 am #

    This Kohler generator looks pretty nice. After the hurricane sandy everyone now I’m sure is thinking of having portable generators at home. Generator is a very big help for Hurrican sandy victims. Rescue teams and medicals sure needs power supply to help those people who are in need of their help. Though, manuals should be read by the owners to avoid harmful effects of having generators.

  4. Greg Johnston
    November 14, 2012 at 5:46 pm #

    I bought a Kohler 14RESAL 14kW Air Cooled Standby Generator for my parents house in New Jersey and I was surprised when they said it was more than enough as I was thinking about the 20kW model but they have a bungalow so I guess it makes sense!

  5. Les Avery
    December 1, 2012 at 11:27 am #


    Please contact me directly. I am the unhappy owner of a new RES 20 which is” hunting” despite all current efforts to correct the problem. I do not wish to damage Kohler’s reputation by publically discussing the known issues but have had no response from the company providing the warrantee service..

    Thank you.


    • CindyLee
      December 5, 2012 at 1:07 pm #

      Hi Les, thanks for reaching out to us. We’re sorry that you’re experiencing some problems and our service team can help you further. Can you e-mail your location along with your generator’s spec and serial numbers to me at GPGsocialmedia@kohler.com? -Cindy

  6. PatMurphy
    March 10, 2013 at 12:38 pm #

    Experiencing similar symptoms to Les. Res20 generator freshly out of warranty hunting badly. The installers cam by on an emergency call to do a firmware update. That changed the behaviour: instead of stopping with an OS (overspeed) error, it now “coughs and chuffs” trying to get out of hunting mode, resulting in brownout conditions for short periods. It does keep going, but it can’t seem to stay “stable”.

    We went with Kohler because of their reputation. Starting to regret that…

    • Cindy Lee
      March 13, 2013 at 2:00 pm #

      Hey PatMurphy, this is Cindy from Kohler Generators. I’m really sorry to hear that you’re experiencing some problems and would like to help. Please email your location along with your generator’s spec and serial numbers to our customer service team at generator.feedback@kohler.com. Let me know if you have trouble connecting with them and I’ll be happy to follow up. – Cindy

    April 20, 2013 at 12:51 pm #


    • Cindy Lee
      April 24, 2013 at 4:00 pm #

      Hey Raymond, thanks for getting in touch with us.

      When the engine has low oil pressure, it will cause your generator to shut down and can lead to excessive damage to your unit. Since low oil pressure doesn’t necessarily mean low oil level, it’s very important that you check and change the oil correctly and in a timely manner.

      On average, you should check the oil every 8 hours and change the oil after every 100 hours of use. Please refer to your owner’s manual for exact specifications.

      For immediate assistance, contact your local Kohler Generator dealer. To locate your nearest Kohler Generator dealer, enter your zip code here: http://khlr.co/b9Uy.

      Please let me know if you have any more questions or need help getting connected. -Cindy

  8. Mali
    May 16, 2015 at 3:36 am #

    How long can my generator run nonstop? We have had a power outage for the past day and my generator has been running the hole time! Is there any thing I need to do to insure she keeps running smoothly? Mali

    • KOHLER Generators
      KOHLER Generators
      May 28, 2015 at 11:40 am #

      Hi Mali – In the event of a prolonged loss of utility power, the unit would be able to run 24 hours per day as long as fuel continues to remain available (via a propane tank or your natural gas utility) and proper maintenance is performed. This maintenance would include checking oil levels on a regular basis (every 8 hours of continuous runtime is recommended) and replacing the oil as needed or after every 150 hours of runtime. The generator’s controller has a total runtime feature to help you monitor this. Recommended maintenance schedules can also be found in the owner’s manual. For additional technical support, please contact your authorized Kohler distributor. Thanks! -Mallory

    • Les Avery
      May 28, 2015 at 5:57 pm #

      I have a 20KW unit (it runs well now, thanks to some tweaking by a good Kohler mechanic). These units will run as long as you have fuel. I ran mine for nearly two weeks. Note oil change requirements, usually after 100 hrs of run-time, about four days. I would not recommend exceeding five days without changing the oil, even if it is full synthetic! If you know how to do it, an oil change should not take more than 20 minutes. Have a filter and the correct oil available before you begin. Follow all instructions in the manual. If you have not done this before, and do not do your on oil changes on your car, watch the professionals do it at least once.


  9. Jim
    June 10, 2015 at 9:15 pm #

    I have a 20kw, and due to a major power / infrastructure failure, we had to run our unit for 35 days straight, 24 hours per day. We changed the oil each week, and checked the oil twice per day. In short, not a single issue, and years later – the machine stills fires up without an issue. Whats the key? maintain and change the oil… Don’t cheap out, use top grade synthetic oil and follow the manual that was provided. Thats it… Don’t be afraid to use your generator for long term outages – thats why you made the investment.