Electricity 101: How Electricity Is Measured and What Makes It Work?

Electricity basics affect everyone. From mechanical engineers and business owners to individuals and homeowners. An easy and basic understanding of how electricity works can help you solve day to day problems and troubleshoot pesky outages. 

So, here’s the big question: How does electricity actually work?

Let’s say you’re a big camper and it’s Christmas time! Your family gives you an exciting Christmas gift:  a 6VDC camping lantern, that allows you to read in the evenings inside of your tent. Excitedly, you plan a local camping trip. Three days into your camping experience, the lantern’s battery dies, plus the 6VDC bulb has burned out as well. Now you’re upset, and deem the lantern a total failure!

You decide to be proactive and take matters into our own hands. Before actually returning your Christmas gift to the camping store, you commit to figuring out what happened.

Top Electricity Basics

You start with the electricity basics.

The three basic units of electricity are:

1. Voltage (V)

2. Current (I) 

3. Resistance (R)

You also know that voltages are measured in Volts, currents are measured in Amps, and resistance is measured in Ohms.

What Is Ohm’s Law?

There is a basic equation in electrical engineering that states that the current is equal to the voltage divided by the resistance, the equation is otherwise known as, Ohm’s law: I = V / R 

You do a little research online and learn that increased voltage in an electric system, creates more current to flow in thru copper wiring. Decreasing the resistance (or electrical load, for example, by swapping the 14 AWG wire into the larger diameter 10 AWG wire) will increase the current flow down the copper wires.

How is Electrical Power Measured?

Electrical power is measured in a term called Watts (W). So, power (P) is equal to the voltage (V) multiplied by the current (I). Otherwise known as the equation: P = (V)(I)

This is great news. You’re starting to catch on that the manufacturer of your camping lantern has mismatched the bulb to the battery, killing them both in just a few short days.

Sure enough – you look at the 6VDC lantern battery, noticing that the label glued on it claims that the battery is 6 VDC and rated for 5 AMPS. Next, you check the bulb. It is clearly marked as 6VDC, 100 Watts and that seems a bit high of a current draw for a simple lantern bulb. 

Using the formula I (amps) = 100W / 6VDC, you divide 100W by 6VDC and get 16.67 amps of current drawn by the bulb, against a 6VDC battery that can only supply 5 amps total. 

You make your way to the camping store, but to your dismay, the camping store has a no-returns policy! However, you are eligible for an exchange. You make your way down the aisle to the light and lantern section, picking up a camping lantern that is 12VDC rated for 10 AMPS. The bulb says, 12VDC / 100W. 

You do the math. I (amps) = 100W / 12VDC

With only 8.33 amps of current drawn by the bulb, against a battery that is rated for 12VDC / 10 amps, you find a perfect match for battery and bulb!

The best part? You’re assured of a few weeks of camping fun, reading your favorite Christmas stories at night!

By simply increasing the voltage and amp rating, matching the DC light bulb to that DC electrical lighting system you are expending less of the current drawn by the bulb.

How The Electrical Power Formula Can Help Homeowners Significantly Lower Monthly Electric Bills 

Simply by changing standard bulbs at home into LED ones, there will be less current against the same amount of AC power. Moreover, just the resistance in the size of the electrical wires used in a home, the AC will consume power. As a result, larger diameter wires are used to reduce the Resistance and lower the heat-induced onto the wiring under load. In fact, most general home wiring uses a 14 gauge (AWG) wire for 120 VAC / 15A service. 

When a homeowner needs to increase the Voltage, for example to 220 / 240 VAC, in order to use a heavy-duty electrical unit like a washer/dryer or powered miter saw motor, the wire Resistance must be lowered by using a larger diameter 10 AWG wire.

These are common everyday household and business examples of how electricity basics can save the day.

What Challenges Does the Electric Industry Face? 

Electric issues are by no means limited to small scale problems. In fact, significant risks and damages can occur, when transient energy interferes with key electrical systems.

Lightning, otherwise known as Sudden or Rapid Induced Transient Energy, is a sudden transient discharge or surge of electric potential that occurs naturally in the atmosphere. This type of surge can also be self-generated from other external sources within an electrical system, building or aircraft. 

Lightening is an extremely high voltage discharge with an extremely high current, which produces a corresponding magnetic field. These magnetic fields can produce currents and fields inside of devices like wires, radio antennas, masthead sensors, and autopilots.

Transient Energy Troubleshooting

A single electric current can damage these sensitive instruments, and solutions like surge protectors offer limited protection. Solutions like adequate grounding techniques or lightning rods can help minimize exposure and add to overall system reliability. Other troubleshooting actions include:

1. Designing systems with EMP in mind

2. Getting clarity on critical systems, what they’re reliant on and which sub-systems are likely to fail

3. Have manual backups for any system that is automated

4. Disconnect and unplug AC cords end electronic devices during storage

Learn more about how the electric industry secures cost-effective mitigation measures that don’t result in drastic consequences and impacts or contact Robinson’s Engineering Consultants for an analysis of your electrical systems.

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