240 Volt Circuits and Switches

By Dave Rongey - Summary:

Electrical Wiring for 240 Volt Circuits and Switches: Each individual pole of a switch or circuit breaker are rated for the stated amperage, the rating is not a combined total of the number of poles.

If this is your first visit, be sure to sign up for your Free Electrical Tips and eBook.
Your Comments and Electrical Questions are always welcome.

Understanding 240 Volt Circuits and Switches

Electrical Question: I purchased a 30Amp, double-pole single-throw switch for a 240Volt circuit dedicated to a steam humidifier for a home ventilation system.

  • The circuit includes 45 feet of 12/3 copper wire and a 15A double circuit breaker.
  • The humidifier which is an April Aire 800, will use 12.7A peak, 11.5A nominal.
  • I’m assuming the switch will be sufficient but is it rated at 30A per line, or is 30A the sum of the maximum amperage for both lines?
  • The switch manufacturer’s web site offered no information.

Thank you.

This electrical wiring question came from: Steve, a Homeowner from Damascus, Maryland.

Additional Comments: Impressive.

Dave’s Reply:
Thanks for your electrical wiring question Steve.

Preparations for Wiring a 240 Volt Circuit

  • Application: Wiring a 240 Volt Switch.
  • Skill Level: Intermediate to Advanced – Best installed by a Licensed Electrician.
  • Tools Required: Basic Electricians Pouch Hand Tools and Voltage Tester.
  • Estimated Time: Depends on personal level experience and ability to work with tools.
  • Precaution: Identify the circuit, turn it OFF and  Tag it with a Note before working with the wiring.
  • Notice: Installing additional electrical wiring should be done with a permit and be inspected.

Electrical Wiring for 240 Volt Circuits and Switches

  • Steve, for your humidifier and ventilation system application you could use a 20 amp two-pole switch because the amperage is within the operating amperage range.
  • Each individual pole of a switch or circuit breaker are rated for the stated amperage, the rating is not a combined total of the number of poles.

More about 240 Volt Circuits and Electrical Switches

Electrical circuit

  • Electric Circuit Listing
  • The size of the home electrical service panel is designed by calculating the square footage of the home and factoring in the code requirements for the electrical circuits that are required.

Circuit breaker

  • Electrical Wiring Protection using Circuit Breakers
  • A guide to home electrical circuit breakers and how they work to protect your electrical wiring. When properly installed, your home electrical wiring is protected by a circuit protection device.

Electrical wire

  • Electrical Wire for the Home
  • Complete listing of electrical wire types and parts used for home projects with electrical code information serves as selection guidelines.

You identified your project to be about 220 Volt Wiring Diagram, so you might find this information useful:

220 Volt Wiring Diagram
220 Volt Wiring Diagram

  • Wiring 220 Volt Electrical Outlet
  • Home electrical wiring includes 110 volt outlets and 220 volt outlets and receptacles which are common place in every home. See how wiring electrical outlets for the home are done.

Learn How to Wire it Right with my
Complete Guide to Home Electrical Wiring
Perfect for Homeowners, Students,
Handyman, Handywomen, and Electricians
Wiring GFCI Outlets
Wiring Home Electrical Circuits
120 Volt and 240 Volt Outlet Circuits
Wiring 3-Wire and 4-Wire Electric Range
Wiring 3-Wire and 4-Wire Dryer Cord and Dryer Outlet
How to Troubleshoot and Repair Electrical Wiring
Wiring Methods for Upgrading Electrical Wiring
Electrical Codes for Home Electrical Wiring
....and much more.

» Click here to learn more about Home Electrical Wiring «
  repair electrical wiring  

Be Careful and Be Safe - Never Work on Energized Circuits!
Consult your Local Building Department about Permits and Inspections for all projects.


Click the banner to Ask a Detailed Electrical Question and get an Instant Reply:
electrical question

FAQs Frequently Asked Questions and Comments

One Response to “240 Volt Circuits and Switches”
  1. rhany siriban says:

    what are the electrical accessories?


If you are asking a Quick Question please make sure it is about This TOPIC:
“240 Volt Circuits and Switches”

Comments Posted here are Open for Quality Discussion and Participation.