Electrical power outlets power all manner of devices that we use on a day-to-day basis. From our lights, the computers we use to work, to the microwaves we cook our food in.
We seldom think about the inner workings of these circuits, which means if you find yourself in a position where you need to wire something, it’s easy to feel completely lost with no idea about which circuit you should be using.
There are, in fact, many different kinds of circuit wiring methods, but the two you will most commonly encounter are series circuits and parallel circuits. Despite both being able to power the same things, the way they work and their most appropriate applications are very different.
The main difference between a series wiring outlet and a parallel wiring outlet is that a series circuit has the current flow in a single direction through every item in the circuit’s path and is unidirectional.
This means the voltage gets split among each component in the circuit’s path unevenly – meaning the first component in the closed circuit receives a higher voltage than the last item in the circuit. It also means if a single component in the circuit fails, the whole circuit fails.
A parallel circuit means the circuit splits into multiple pathways, so each component sits on its lane and is not directly connected to another component. This means each component receives an equal voltage as the source.
Additionally, if a single element dies in a parallel circuit, all the other elements will continue to function as normal as that failed component is on its pathway.
What is series outlet wiring?
As the name suggests, an electrical outlet wired in series means that each component is in sequence, and the current flows directly through in a single direction.
A typical example of this you may have encountered are Christmas lights, where the electrical current will flow straight from the electrical outlet into the first light bulb, then into the second, all the way to the end.
This means that if a single bulb were to blow, the closed circuit would be broken, and all the lights would turn off, which makes troubleshooting them very hard.
So why use it then if it carries this risk?
For many large-scale and industrial situations, such as where many fans or lights will need to be switched on, they are often connected by a series wiring outlet, making it easy to control with a single switch. It’s far less complicated than dealing with many devices in a parallel circuit.
Additionally, a series circuit may be used for many simple devices that don’t need more complicated parallel wiring as they only have one component.
This can include devices such as:
- A simple lamp
- A flashlight
- A freezer
- A water heater
- A refrigerator
Of course, there are many other applications of a series outlet that you will encounter throughout your day-to-day life. Many street lamps, for example, are still connected by series, which is why they always fail in batches.
For that reason, you will seldom see series wiring outlets used around the home, and it is generally reserved for larger-scale settings.
What is parallel outlet wiring?
Unlike a series circuit that uses a single path, a parallel circuit splits into multiple paths, placing multiple series circuits parallel.
Putting each component on its path means that the electrical current gets divided amongst each outlet so it can be controlled individually.
Plus, if any of the individual paths were to be interrupted for some reason, all the other paths would continue to work as they are on a different lane.
Unlike a series circuit, each path is given an equal voltage with a variable current.
A good example of this would be in a home situation, where you might have the lights, a heater, and a fan in parallel, so if the light bulb were to blow, all the other devices would continue working.
This makes a safer and more practical wiring scenario for most home applications. Particularly in lighting, you’ll never have the entire house go dark because of a single failure.
Likewise, you will see also this used in car electronics, so if a single light fails you, the others will still work, and you can see where you are going. This is an essential use of a parallel circuit for safety reasons.
You will less commonly see parallel wiring in large commercial applications due to the complexity of the system when you have too many devices that need to be run in parallel.
What are the differences between series and parallel outlets wiring?
These wiring types can be found frequently throughout our daily lives. Still, their intended use case scenarios differ hugely because of their attributes which make them better suited for specific jobs over others.
Let’s take a deeper look at what differentiates these circuit types to understand which kind is better for a given situation.
1. Number of branches
The series wiring circuit has just a single branch or path which passes each device into the next one in a linear fashion. A parallel circuit splits into different lanes or ‘parallel circuits’ where each device sits by itself and doesn’t flow directly into the following device.
This affects how the circuit reacts in the case of a component failure and the power supply distribution heading to each device on the circuit.
2. Common use case scenarios
You will most commonly see a single branch series circuit used for particular devices with only 1 point of failure.
But it is also used in large-scale industrial settings where you may have hundreds of devices where controlling them on a single-lane circuit provides speed and convenience. These settings are often too complicated and troublesome to deal with a parallel circuit.
A parallel circuit is better suited for scenarios where safety is a concern, so if 1 component fails, the other devices will remain functional. It’s not needed for single-device circuits.
3. Direction of the current
The electricity current direction on a series circuit is ‘unidirectional,’ meaning it only flows in a single direction. This is because there is only a single lane, so there is no other direction the electric current can split, which is also why any interruption in that lane affects every device in the circuit.
On the other hand, a parallel circuit is ‘multidirectional’ as the current can flow in more than one direction due to the wiring path being split into multiple lanes and to multiple devices. This means an interruption to a single lane will not stop the entire circuit from working.
4. The voltage distribution
On a single-lane circuit, the voltage is distributed amongst each device within the circuit. The first device on that circuit receives the most current, and as it passes through each device, that current diminishes, with the last device in the chain receiving the least current.
On a parallel circuit, each lane receives the same voltage as the input no matter what, meaning each device gets the same amount of juice.
The only exception is that a singular parallel lane has multiple devices on it, which acts as a ‘mini series’ circuit within the larger parallel circuit. In this case, the voltage will be distributed similarly to a series circuit between all devices on that individual lane.
5. The current distribution
In a reversal to the voltage distribution, each device on the series circuit receives the same current, whereas, on a parallel circuit, it’s divided amongst each device.
6. Is it appropriate for home use
Because a single failure point in the circuit will cause every device to stop working, a series circuit is considered unsuitable for home use. Imagine your freezer not working because a light blew!
Not only is it just generally troublesome to have your entire home go down because of a single failure. It’s against the electricity code guidelines and is considered a safety hazard.
A parallel circuit, on the other hand, is generally advised for homes as most of your home appliances can continue functioning, as usual, should a problem occur. This is much safer and far less troublesome to deal with.
7. Power draw amounts
The power draw will diminish with each device you add to a series circuit. So the first device will consume the most power, with each subsequent drawing less and less, with the final device drawing the least.
A parallel device will draw equal amounts of each lane within the circuit, which is generally a safer option as you can be sure each device is powered evenly.
8. Effects on other devices
When a single device breaks the power flow on a series circuit, it will prevent all other devices on that wiring outlet from functioning.
On a parallel connection circuit, as each device is on its lane, if a single device fails, only the devices on that singular lane will stop working, and any device on a parallel lane will continue to function as expected.
Because a single point of failure will bring down the entire circuit if it’s wired in series, it’s generally considered a less reliable circuit type. It is only used for convenience where a parallel circuit would be too troublesome.
A parallel circuit will keep functioning as usual when a device fails, making it a much safer and more reliable option, particularly anytime safety is involved. Areas need to be lit, such as a home or car.
Series vs parallel outlets wiring: Are they the same?
While both wiring types can power devices fine, their intended use cases are quite different due to how failure points and power distribution within the circuits work.
- A series circuit places each device in a linear sequence, whereas a parallel connection circuit splits off into multiple lanes, placing each device parallel to the other.
- Series circuits are more commonly used on simple circuits that don’t have multiple failure points or large-scale applications where hundreds of devices need to be managed with a single switch. Parallel circuits are generally better suited for home use.
- Series circuits have a ‘unidirectional’ or ‘one-way’ current that flows in a single direction. But a parallel circuit’s current is multidirectional.
- Each sequential device within a series circuit receives less voltage, but a parallel circuit delivers equal voltage to each parallel lane on the circuit.
- The current on a series circuit is the same for each device. But on a parallel circuit, it’s split between each parallel lane.
- Because a single failure will shut down the whole circuit, series wiring is considered less appropriate for home use than a parallel circuit that will keep working if a single device fails.
- Each device on a series circuit will draw less and less power, whereas every device or lane on a parallel circuit will draw equal power.
- If a device fails on a series circuit all other connected devices will stop working. If a parallel circuit device fails, only things connected to that single lane will stop working. Everything else will remain functional.
- Generally speaking, parallel is considered safer and reliable but perhaps less convenient when managing large numbers of devices compared to a series circuit.