The basic components of electricity are relatively easy and logical to understand. Most electrical terms relate and get along with each other like a harmonious family. Before you tackle any electrical or home wiring project, familiarize yourself with the following terms so you can go about them smarter, safer and without apprehension.
What Is a Watt?
Watts are units of electric power. Think of wattage as electricity at work when heating or illuminating a room in your home. Take a portable electric space heater Rated at 500 watts, this space heater uses up 500 watts of electricity whenever it is activated.
You'll also come across wattage when choosing. light bulbs To locate an incandescent bulb that provides similar illumination to the burnt-out one, you should examine the wattage. Moreover, the wattage rating of an appliance is typically indicated on its nameplate.
What Is a Volt?
Voltage acts as the force that drives electrical current through a wire.
In North America, utility systems generally supply electricity to your home’s service panel at voltages of 240 and 120. Large electric devices such as ranges , clothes dryers, water heaters , air conditioning and space heating systems Typically run on 240 volts. All other devices use 120 volts.
What Is an Amp?
Amperage indicates how quickly electricity moves through an electric circuit. To liken it to plumbing: if voltage represents water pressure, then amperage signifies the speed at which the water travels. "Amps" serves as the abbreviated term for this measurement.
During installation, modification, or replacement of branch circuits within your residence, you'll notice either fuses or circuit breakers inside your electrical panel. circuit breakers Of varying dimensions. General-purpose illumination and electrical socket circuits have a rating of 15 amps. In more recent building projects, you will additionally encounter specialized 20-amp circuits designed for areas like the kitchen, bathroom, and laundry room. garage receptacle outlets along with appliances such as a dishwasher or refrigerator.
Electric clothes dryers and electric water heaters usually have a rating of 30 amps. Air-conditioning units Electric ranges along with electric countertops or wall-mounted electric ovens can have ratings of 30, 40, or 50 amps.
Every electrical component in your house should be integrated properly to ensure safe operation. The amperage rating of the fuse or circuit breaker determines the appropriate wire gauge and sets limits for the circuit’s capacity. Should you require additional amps, larger wiring will be necessary.
What Is an Ohm?
An ohm (denoted by the Greek symbol Omega, or Ω) quantifies the resistance present within any material or component. electrical wire . Copper wire, an excellent conductor of electricity, is found throughout many homes. Aluminum wire, another good conductor, can be found in commercial, industrial and utility installations. Both have inherent resistance to the flow of electricity.
Wires made from different metals have different resistance values, just like a small garden hose will limit the flow of water compared to a large fire hose.
When you troubleshoot electrical circuits, appliances, light switches, fuses, relays and other electrical components with a multimeter, some of the settings and readings will be expressed in Ohms. When you check the continuity for a new fuse, the multimeter will read approximately zero Ohms of resistance. That means the fuse has continuity and is good.
On the other hand, if you check a suspected defective fuse or broken light switch, you’ll probably get an Ohm reading other than zero. That may indicate a blown fuse or broken light switch. Consult the multimeter’s user manual so you can operate it safely and interpret the readings.
How Do Watts, Volts, Amps and Ohms Relate to Each Other?
Electrical math is straightforward. If you know two variables, you can find the result. If you know “x” and “y,” you can solve for “z.”
There are many laws in physics, science and nature, and Ohm’s Law is one of the most important in understanding basic electricity. And the Ohm’s Law Wheel helps make sense of it.
Here’s an example of a practical application. Say you’re installing an electric space heater in your garage. There’s a 5,000-watt (five-kilowatt or 5kW) space heater on sale at the hardware store that’s perfect for the space. What size circuit will you need for the space heater?
According to the nameplate, the space heater is rated at 5kW and must be supplied with 240 volts. So you need to solve for the amps (represented by the letter I for “intensity of current”). When you look at the Ohm’s Law Wheel, select this formula:
I = W/E (amps = watts ÷ volts);
I = 5,000 watts ÷ by 240 volts;
I = 20.8 amps;
Because the electric space heater on a continuous load could operate for three or more hours on a cold day, a safety factor of 125 percent is applied. So 20.8 amps x 1.25 = 26 amps.
All done! A standard 30-amp branch circuit will have adequate capacity to supply electricity continuously and safely for the space heater.
How To Work Safely on Your Home’s Electrical System
- Electricity is an invisible phenomenon we take for granted. Working with electricity does not need to be dangerous or difficult if you know how it works, treat it with respect and take basic safety precautions. Learn how to safely use electrical tools and testers.
- Make sure your electrical tester or multimeter is working properly before turning off the power.
- Always turn off power to circuits before working on them. Put a label, sign or circuit breaker lockout device at the electrical panel so nobody inadvertently turns the power back on. You’ll find a variety of universal circuit breaker lockout devices at home centers and online for less than $10.
- Always use protective eyewear and nonconductive leather, rubber, latex, nitrile, or comparable dry gloves. Opt for attire made from natural fabrics rather than synthetic ones.
- Wear appropriate durable shoes and avoid standing or kneeling on wet or moist surfaces while handling electricity. Utilize a dry, nonconducting wooden object instead. nonconductive mat, especially when working outdoors.
- Utilize tools featuring handles made of rubber or plastic. These nonconductive handle materials offer an additional layer of defense against electrical risks.