A electrical load generally refers to one of two things. One is any appliance or gadget that draws electricity from a power source. The other is the total draw of all appliances and gadgets on a circuit or set of circuits.
You’ll hear the phrase “electrical load” a lot whenever you deal with an electrical issue. If you call an electrician for an inspection or to figure out what’s causing things like a buzzing sound or breaker switches that trip, the electrician will want to know what sort of electrical load you’re placing on the circuit because the load is often the culprit.
Electrical loads themselves aren’t bad. But when the load is too great for the circuit, that’s when things start to fail. By knowing the loads you’re placing on each circuit in your home, you can more easily determine where a problem originates from.
Quick Takeaways
- An electrical load is any appliance or gadget that draws electrical power.
- Anything in your home, office, car or other location that uses electricity is an electrical load. That includes lamps, computers, electric stoves, the electronic ignition on a heater, TVs and motors. (GFCI outlets that have indicator lights can be loads themselves.)
- The units that you use to measure electrical load are watts and amps.
- Electrical loads can exceed (meaning they draw more power than is available) the amount of power that a circuit provides. That makes the breaker switch trip and can cause wiring to overheat.
- Most electrical load problems need a professional to conduct troubleshooting.
What Is an Electrical Load?
An electrical load is any device or system that draws electricity from a circuit and uses it to do work. “Do work” means to function, turning the electricity into heat, light or some form of motion. Your TV takes electricity and turns it into light. Your fan takes electricity and uses it to create motion. Your rice cooker takes electricity to create heat that cooks food.
Electrical loads aren’t the same as power sources. Power sources turn another fuel into electricity and are things like batteries, which use stored chemical potential to create electricity, or power plants that use fuels like natural gas or nuclear power to generate electricity.
Why Electrical Load Matters in Your Home
Your home contains a circuit breaker box, or if it’s a much older and un-updated home, a fuse box. The box takes the power coming in from the utility lines outside your home and divides it between circuits. When a breaker switch is turned to its on position, it allows a specific amount of power to flow to a circuit, connected to one or more outlets.
If you plug in too much and draw too much power, the circuit breaker trips, or snaps into the off position, cutting off the power so that no current flows to those outlets. Flip circuit breakers back to their on position to restore power.
The breakers come in 15 or 20 amps per switch. (Larger appliances may have a dedicated circuit that provides up to 50 amps.) Those limits exist to protect the wiring in your home.
The wires that bring the current to the outlets come in specific gauges, or diameters. Gauge numbers run higher for thinner wire, which can carry less current. 15-amp breakers use 14-gauge wire, and 20-amp breakers use 12-gauge.
If you plug in appliances that have a cumulative electrical load that exceeds the capacity of the breaker, the breaker trips and switches off. Occasionally, the breaker won’t switch off right away, especially if the excess load is tiny. However, you may hear buzzing, see lights flicker or notice outlets overheating. You really don’t want to exceed circuit breaker capacity.
Common Types of Electrical Loads
Not every electrical load works in the same way. They’re categorized by how they use the electrical power to run.
Resistive Loads
Resistive loads take electricity and convert it to light, heat or both. An incandescent bulb uses electricity to produce light and heat. A toaster or space heater uses it to create lots of heat (which in turn creates a little light as the elements inside the appliances glow when they heat up).
Inductive Loads
Inductive loads take the electricity to run a motor or create a magnetic field. For example, your refrigerator uses electricity to run the motor that then cools the refrigerator (The light bulb inside the fridge is resistive.)
Inductive loads often require an initial burst of power or startup load to start working, drawing a larger amount of electricity before dropping down to its regular operational load.
Electronic and Mixed Loads
LED bulbs, computers and other tech gadgets tend to fall under electronic and mixed loads. These aren’t considered resistive because the mechanisms inside them treat electricity differently. The current isn’t directly used to create the heat or light.
How Electrical Load Is Measured
The units of measurement for load are watts and amps. Technically, watts measure the power that the item consumes. Amps measure the power output or flow of the circuit.
Occasionally you’ll see an appliance give a load measurement in amps, and you can convert between the two.
Watts divided by voltage equals amps, and amps times voltage equals watts. The voltage is the electrical potential. In the U.S., voltage for most typical home outlets is 120 volts.
The numbers you see on circuit breakers, 15 and 20, matter because those tell you the maximum current flowing to the outlets on the circuits. Note that total load matters more than individual load.
If you have six 500-watt items that you want to plug into a power strip that’s plugged into an outlet on a 15-amp circuit, that’s 3,000 watts or 25 amps. You’d trip the breaker.
If you have two outlets on a 20-amp circuit and plug a 1,200-watt toaster oven into one outlet and an 1,800-watt air fryer into the other outlet, that’s again 3,000 watts or 25 amps, and too much together for the circuit. If you turn on only one at a time, you’ll be fine. If you turn on both at the same time, the circuit breaker will trip.
What Happens When an Electrical Load Is Too High
When the load is too high, the breaker usually trips. But it can also result in buzzing, flickering and vibrations. If you ignore those problems, you face a fire risk.
Signs You May Have an Electrical Load Problem
Look and listen for the following:
- Frequent breaker trips
- Lights that continually flicker or dim
- Buzzing from switches or outlets
- Switch or outlet plates that are warm
- Sudden problems when you put new appliances on a circuit
Electrical Load vs Electrical Usage
The load is the amount of power something draws from the circuit. The usage is how long that draw goes on. The longer you use an electrical load, the more power it will consume, which increases your power bills.
It also increases the risk the breaker could have a shorter lifespan if the load is constantly excessive and causing frequent trips.
When Electrical Load Issues Require Troubleshooting
Tripping a breaker once in a while because you accidentally plugged in too much isn’t a problem. You can reset the breaker yourself and redistribute electrical load. But if the breaker keeps tripping, you need to call a professional.
An electrician can take a look at shared circuits and look for hidden overloads. This is why electrical load matters so much because it tells the electrician what’s trying to draw power on a circuit with problems.
How Electricians Troubleshoot Electrical Load Problems
Electricians use the following to find the cause of electrical load problems:
Circuit testing- Load calculations
- Panel evaluation
- Wiring inspection
- Finding unsafe loads
FAQ
What is considered an electrical load in a house?
Anything you plug into an outlet is an electrical load, like your TV, phone charger, lamp and so on.
Can too much electrical load cause a fire?
Yes, if you ignore problems or continue to overload circuits.
Why does adding one appliance trip my breaker?
You’ve added something that draws enough power to make the total electrical load exceed the breaker’s capacity.
Is electrical load the same as electricity usage?
No. The load is what draws power (e.g., a lamp). The usage is how long it draws power for (e.g., five hours).
How do I know if my home has an electrical load problem?
If you’re frequently resetting breakers, hear buzzing, see flickering lights or feel warm switches and outlets, call a pro for an inspection.
Don’t Ignore Breaker Problems
Electricity makes life convenient, but when there’s a problem, you don’t want to let it go. Fixing electrical load issues involves more than just resetting the breaker. If you’re noticing these problems, call Lakeland’s on-time electrician for expert electrical troubleshooting.