Readers, especially the ones who are interested in DIYing their wiring system, often ask us whether it would be okay to use one neutral for two circuits. The short answer is yes. While this may seem like a simple job for the experts, there are many intricate details involved in the process.
We have designed this article to walk you through the entire process. We will discuss whether you can use one neutral for two circuits, and in which instances. We will further discuss the reasons behind this multi-wiring system and the requirements that it entails. And finally, we will present a step-by-step guide to help you through the wiring process. So read ahead to learn all about it.
Can I use one neutral for two circuits?
You can use one neutral for two circuits. This process is called multiwire branch circuit. But you will need to adhere to the rules and codes in order to ensure proper safety. There are many details involved in the process, including the usage of a double-pole breaker. You can get professional help.
It is often a matter of concern whether we can use one neutral for two circuits. This would make the wiring process much simpler for us. So it seems like a lucrative process. But there are many intricate details involved here.
We can definitely use one neutral for two circuits. But there are several rules and codes that we will need to adhere to in order to make sure that the wiring is safe. You will need to be very careful during the wiring process, especially if you lack experience and expertise in this area. Make sure to get it checked by an expert once you are done.
There are several conditions associated with this process. And you will need to pay close attention to how the wiring system is responding to the neutral.
Make sure that the two breakers that are sharing the neutral are on the same leg of the panel. You should not share the neutral in any other circumstances. This system is called a multiwire branch circuit. In order to ensure its safety, you will need to go by the book. Follow the rules in each step and you will be able to build a good wiring system.
And note that, this wiring will need a double-pole breaker, as we have mentioned earlier. Keep in mind that while you are building this wiring system, there are two or multiple ungrounded conductors or phases that have a shared neutral and voltage between them.
So you will need to be very careful while dealing with the system, even if you are a professional. Make sure to follow all the protocols and safety measures while you are working.
Can you share a neutral with multiple circuits? Is it okay?
Generally speaking, you can share a neutral with multiple circuits. But there are many factors associated with it. You will need to check how the circuits are placed and protected.
It is okay to share a neutral with multiple circuits. However, keep in mind the following factors.
If the circuits are protected by an RCD or GFCI type of device, then the lines should not be connected to a neutral line that does not have a similar type of protection. In addition, you should not connect such circuits to neutral lines that do not have any protection at all.
How many circuits can share a neutral?
Multiple circuits can share a neutral. But you will have to make sure that the wires are of the same size. The wires will also need to be of the same type. In addition, make sure that the wires in the neutral are connected properly and are secured.
But note that you can only have one neutral in a circuit if you are opting for a single-phase wiring system. This is a current-carrying conductor, so you will need to be particularly careful about the details of the wiring.
It is likely that when you are using multiple circuits in a neutral, it may exceed the capacity of the conductor. This will end up damaging the conductor. It may even pose a fire breakout. So you will need to be very careful while installing the wiring system.
2 reasons why you can use one neutral for two circuits
Here are two of the most prominent reasons why you can use one neutral for two circuits.
Smooth power distribution:
One neutral is often used for two circuits in order to ensure large power distribution facilities. You will notice that many hospitals, schools, factories, hotels, and large residential buildings use one neutral for two circuits. It ensures a smooth lighting system and receptacles in large establishments.
Simultaneous disconnection:
When two circuits use one shared neutral, there will be a simultaneous disconnection for both circuits when there is any power cut. So this makes it rather easy to control the power supply in large establishments.
However, this process might not be very feasible all the time. So people are now moving away from shared neutral for two circuits. It creates some major inconvenience as well.
However, this step is very important in order to ensure the safety of the operator. You will need to disconnect all the wires in the branch circuit, regardless of whether they are working or not. This will ensure that the circuit is safe to work on. Otherwise, there will be a possibility of electrocution.
What is required when running 2 circuits that share a common neutral?
There are several rules and regulations that you will need to adhere to while running two circuits that share a common neutral. Read ahead to learn more about the requirements.
Split wired receptacle:
You will need a split-wire receptacle in order to ensure an efficient multi-wiring system. This is required when running 2 circuits that share a common neutral.
It is a duplex electrical receptacle that will be changed into two singles. These receptacles are electrically independent, either partially or completely. You will also have to ensure that each receptacle opening of the pair is supplied individually with electricity by a fuse of its own.
Disconnect simultaneously:
You will need to ensure that there is a simultaneous disconnection of the multiwire branch circuit, which will supply electricity to multiple devices on the same circuit.
That is to say, you will need to make sure that each circuit has a means or device that will help disconnect the multi-wiring system simultaneously. You will need to disconnect all the underground conductors at the same time to the originating point of the branch circuit.
So you will have to disconnect all the circuit conductors on the circuit when you’re performing some sort of work on them, it does not matter whether they are working or not.
Grouped by cables:
Now you will have to group the cable tires. It is a requirement that you have to group all the grounded and undergrounded using cable tires inside the panel board. This will help you make sure that the wires are connected correctly.
However, there is an exception in this case. The requirement for grouping does not include the circuits that enter from a cable into the circuit.
How to wire a shared neutral circuit?
Here’s how you should wire a shared neutral circuit:
Selection:
The first step involves the selection process. You will need to select the number of phases that you are willing to deal with. You will also need to select the type of wires and cables that you will work with.
You will also need to find a two-pole breaker for this job. These breakers are great for installing a shared neutral.
Several combination types are suitable for a shared neutral. You will need to identify them.
Installation process:
Now you will need to connect the two one-pole breakers to a shared neutral circuit. But first, you will need to connect the handles with a handle tie.
Note that the handle tie will help you with the on and off switch between the two one-breaker devices.
Now you will have to connect the black conductor to the load lug of the first circuit. Afterward, you will have to connect the red conductor to the load lug of the second circuit.
Final Thoughts
Yes, you can use one neutral for two circuits. The multi-wiring process involves many intricate details, so you will have to be very careful. You can also take help from professional service. You will have to make sure to adhere to all the regulations in this case.