What Size Generator Do You Need For 240 Volts?

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Find out what size generator you need for 240 volts so you can avoid investing in a machine that does not suit your needs.

First of all, the smallest quality 240 volt generator on the market already has 4000 peak watts and 3500 running watts.

In that sense, you can say you need at least this size to be able to power 240 volt devices.

After that, your power needs will mostly depend on how many amps your devices need.

For example, with the Watts = Amps x Volts formula, you can calculate that you need a generator with at least 4800 running watts to run a device that needs 240 volts and 20 amps.

Generator power capacity requirements for 240 volts

While it is not always enough, the Watts = Amps x Volts formula can be a good place to start to find what your generator needs to run 240 volt devices.

For example, let’s say you have a 240 volt tool that only needs 10 amps to function.

In that case, your generator would theoretically only need 2400 running watts to power this device.

On the other hand, a 30 amp device that uses 240 volts would need a generator with at least 7200 running watts.

Even bigger, you would need a generator with 12000 running watts to power a machine that needs 50 amps at 240 volts.

However, at the lower amp needs, the formula above could be lacking.

How big generators actually have to be for 240 volts

The main reason a 2400 running watt generator is generally not enough for 240 volt devices is that they are not made to produce this many volts.

More specifically, the smallest 240 volt generator is the Honda EG4000 with 4000 peak watts and 3500 running watts.

You will simply not find good 240 volt portable generators with watt amounts smaller than that.

In turn, you can say you need at least a 4000 peak watt size generator for 240 volts.

And a bigger model if your 240 volt device needs more than 14.5 running amps.


Can you run 240 volts on a generator?

Whether you can run 240 volts on a generator will vary from machine to machine.

There are definitely portable generators that can handle this amount of volts.

At the same time, smaller models often do not offer this much power.

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Mats is the founder and head editor of Generator Decision. With a combination of critical thinking, tireless research, and a healthy interest in electronics he helps people find the right generators and how to use these. At this point in the journey, Mats has done research on hundreds of portable generators.