Volts vs Amps vs Watts Explained: Simple Electricity Guide⚡

WHAT VOLTS, AMPS, AND WATTS ACTUALLY ARE: EXPLAINED

Volts, amps, and watts are the three core units of electricity. Volts measure electrical pressure, amps measure flow, and watts measure total power (volts x amps).

Using a hose analogy helps visually explain the difference between volts, amps, and watts:

• Volts (voltage) refers to the electrical pressure, like how open or closed a tap is.
• Amps (current) measure the flow of electricity, similar to water running through the hose.
• Watts (power) represents amount of power used or produced, calculated by multiplying volts by amps.
• Ohms (resistance) refers to the amount electrical resistance, like how a hose can be restricted.

Similar to our water hose example, electricity is simply a form of energy where electrons move. The flow of charged particles (primarily electrons) is also known as an electrical current which is sent to power devices like phones and lights.

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WHAT ARE VOLTS? VOLTAGE (V) EXPLAINED AUSTRALIA

Voltage (Volts) measures the amount of electrical pressure pushing electricity through a circuit. The higher the voltage, the greater the electrical pressure available to move current.

How to calculate voltage: Voltage can be calculated by dividing the amount of power by the current. (watts ÷ amps = volts).

What's an example of Voltage? Like we see in the hose analogy, voltage is what measures the electrical pressure that pushes current (amps) through a wire or cable, which at higher pressures (volts) it makes it easier to push the electrical current through the circuit.

What Voltage do Homes Run at? Australian household outlets run at 230-240V single-phase by default since 2000, which operates at enough volts (or pressure) to run everyday household appliances like fridges and lights.

What Voltage do Transmission Lines Run at? Long-distance transmission networks can run up to 220 kilovolts (kV) or 220,000 Volts (V), which are designed to run at high-voltage and lower current to reduce power losses.

WHAT ARE AMPS? AMPERAGE (A) / CURRENT EXPLAINED

Amps (amperage) measure the amount of electrical current flowing through a circuit. In simple terms, it's how much electricity is moving at any given time.

The higher the amps, the greater the flow of electrical current, provided the cable and system are designed to handle it safely.

How to calculate current: Amps can be calculated by dividing watts by voltage. (Watts ÷ volts = amps).

What Amperage do Appliances Run at? Appliances like standard fridges run at around 1-3 amps, and a standard light bulb run at around 0.07 amps or 77mA (milliamps).

Because every cable or wire has at least some resistance (ohms), energy is lost which generates heat. The higher the current, the more heat that is generated, so for higher capacity, thicker cabling is used to reduce the resistance and heat buildup.

Higher voltage with less current enables the same power delivery which reduces heat loss and improves overall efficiency.

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WHAT ARE WATTS? WATTAGE (W) & KILOWATTS (KW) EXPLAINED

Watts (W) measure the total power bring used or produced in an electrical system. Wattage or Watts (W) measure the power which involves combining the volts and amps.

How to calculate watts: Watts can be calculated by multiplying voltage and current (volts x amps = watts).

What's an Example of Watts? Using our hose example, power also applies to water where the amount of power is determined by the combined flow and pressure. Imagine your thumb over the hose nozzle, when the high flow is pressurised, it jets out a powerful flow; this is what electrical power is like.

The watt measurement is used for specifying device charging speeds (e.g., the fastest phone charging rate is 240W)

What's the difference between W and kW? Watts and Kilowatts are both measurements of power. 1000W (watt) is equal to 1kW (kilowatt), which measures the amount of power being used or produced.

WHAT ARE OHMS? ELECTRICAL RESISTANCE(Ω) EXPLAINED

What are Ohms? Ohms, also symbolised as ‘Ω’, represent the resistance in an electrical circuit, measuring how much that it resists flow (amps).

What's an example of Ohms? Using our water pipe analogy, think of Ohms like a narrower pipe that further restricts the amount of water flow there is. Higher resistance in a cable means that less current will flow and energy loss will occur.

Does electrical resistance generate heat? Another aspect to note is energy loss that resistance creates. This could be represented by a small hole in the hose where water (or electricity) escapes before its destination and causes lost energy to be lost. In the electrical case, it’s lost as heat.

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WHAT ARE PHASES AND FREQUENCIES IN AUSTRALIA?

What does frequency (Hz) mean? Every home runs on alternating current at 50-60Hz. The frequency (Hz) is the number of times the alternating current switches direction per second.

How many volts is a phase? Most homes are generally single-phase, which runs at 230-240V per phase, with three-phase properties reaching 400V for more power.

What is an electrical phase? A phase (Φ) is simply a method of delivering power to your property. The more phases, the more power can be delivered to homes and businesses that require a higher power output to use appliances like EV chargers or industrial equipment.

Using the water analogy to determine what a phase is, think of it like a single or three water pipes supplying your house. A solo pipe can only provide so much flow at a given time, and with some needing more than what that one pipe can supply, they can opt for more and upgrade to three-phase.

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WHAT ARE REAL LIFE EXAMPLES OF VOLTAGE, CURRENT, AND RESISTANCE?

Understanding amps, volts, and ohms shouldn’t just be limited to the academics, but be something in the back of your mind to help you know how your appliances operate.

Appliances like EV chargers and kettles require a higher amount of power for their operation, which when used all at the same time, can trip circuit breakers which are designed to stop electricity flowing and protect your appliances from too much current.

Yes, you guessed it, let’s refer to our water analogy. Circuit breakers and fuses both stop the flow of water when too much water is going through the hose which is a safety guard for protecting your home.

The difference between a fuse and circuit breaker comes down to a fuse being the last resort and requires replacement when broken and a circuit breaker being resettable.

WHAT IS GRID OVERVOLTAGE? HOW HOMES ARE PROTECTED FROM IT

Because voltage is the pressure pushing the electricity through your circuits, it is vulnerable to get too high or too low. When voltage gets too high, appliances are damaged, and too low means that it won’t work properly. Both not ideal.

As mentioned before, transmitting electricity long-distance requires high voltage over hundreds of thousands of volts... but how is this made suitable for homes?

What are electrical transformers? A very important part of the electrical system called the Transformer, is designed to step up or down the voltage to the required value. When reaching the end of the transmission line, transformers gradually step down the electricity’s voltage as it approaches your neighbourhood and house to the suitable amount.

Courtesy of Transgrid