We depend on electricity for so much in our daily lives. Whether it’s work, entertainment or providing light and heat, every home is full of a variety of devices and appliances that run on mains electricity. Our houses are connected to the national grid, and this supplies us with the power that our devices need.
While we all use electrical appliances daily, very few people have an understanding of how this system works. Unless you’re an electrician, there probably aren’t too many reasons why you’d need to know the inner workings of the electricity grid. However, it’s good to have knowledge of how these devices work in case you ever have an issue and need to fix it.
Where Does Mains Electricity Come From?
Mains electricity enters your home through underground cables protected by conduits. It travels directly through these cables and along power lines from the utility company. When travelling through cables and power lines, the current is normally carried at extremely high voltages. Anything between 300,000 and 750,000 is common, which is why these cables can be so dangerous.
Before it can enter our homes, it has to be reduced to a safer voltage through an electrical transformer. These devices pass the electrical current between two coiled wires to decrease the voltage, making it safer and allowing it to be sent to our homes. Electricity travels at high voltage because this way, less energy is lost through heat.
The Main Panel Board
Once the electricity reaches your home, it passes through the main panel board. Every house with a connection to the power grid has a panel board, sometimes known as a distribution board or distribution panel. This is one of the most important parts of your home’s electrical supply. The purpose of the panel board is to receive the electricity and then distribute it around the home to the individual circuits.
You can think of the panel board as being a central hub, where the main power cable enters, and the current is split into different cables to feed other circuits. The board also features a main switch to turn the entire power off and on, as well as the circuit breakers, earth leakage units and busbars. These all help to protect your home and devices from electrical hazards, keeping you safe.
Circuit breakers detect increases in power within the home’s mains power supply. When a surge in power is detected, they break the circuit to protect the rest of the power system. This prevents your devices from being damaged by excess power and can also help to prevent electrical fires and other issues.
The earth leakage units are also designed to break the circuit for safety purposes. In this case, they detect instances where the voltage has reached the metal casing of appliances and devices, helping to prevent electric shocks. Busbars then help to ground and conduct electricity through the panel, ensuring safety and an efficient current.
Completing the Circuit
Once the electricity passes through the panel board, it can be sent throughout your home to your sockets and outlets. Electricity can only flow when there’s a completed circuit, allowing the electrons to pass through the wires and power the device before returning to the same place in a circular journey. When you activate a switch, the electrons flow through the circuit, but there’s no current if the circuit is broken.
When you plug a device into a socket, it introduces a new circuit for the electrons to flow through. UK homes use 230 volts mains power as standard, though many devices don’t require that much power. In these cases, the plug used will have its own version of a small transformer to decrease the voltage and allow safe usage.