20 amp circuits are usually run in commercial properties like office buildings or storefronts. But nowadays, you can run a 20 amp circuit on both commercial and residential properties due to the increased use of electrical appliances.
If you have a 20 amp circuit, you can have about 2000 watts(40 lights with 50 watts each) of led light or 10 outlets of 1.5 amp or a combination of both with a total load of 16 amps. A good rule of thumb is to stay within 80% of the circuit rating to avoid overload and tripping of breakers.
However, there are a lot of things to know. This guide will answer your doubts regarding the number of lights and outlets in the 20 amp circuits together and separately and the factors to consider while putting them in the same circuit.
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Can I put lights and outlets on the same circuit?
There is no problem in putting the lights and circuits in the same circuit. However, it is recommended not to add them together.
Sometimes, the fuse blows due to the overloading of outlets and lights.
In that case, you have to change the whole circuit, including the lights and outlets.
Most people choose 15 or 20-amp circuits as these are the common ones that supply outlets, lights, or both.
How many lights and outlets can I add to a 20 amp circuit?
NEC code recommends adding lights and outlets in separate circuits to avoid fuse blow and overloading.
The norm is to add lights in 15 amp circuits and outlets in 20 amp circuits.
However, you can still install the lights and outlets in the same 20 amp circuit within the code rules.
Each light you add to the circuit will take the place of an outlet.
Generally, you can run only 10 outlets in the 20 amp circuit.
If you are adding lights in the same circuit, add 2 lights and 8 outlets, which is 10 lights and outlets.
Sometimes, you can install 12 lights and outlets, provided you use low-wattage lights.
The circuit rating should not exceed 80%.
No matter how many lights and outlets you add, you should keep in mind the regulations, the loads, and the rating of the circuit.
The fuse will blow your lights and outlets if the rated load exceeds too much.
Some factors must be considered while adding lights and outlets in the 20 amp circuit.
You must follow the rules and regulations while running the lights and outlets in a circuit.
Besides the NEC code, each locality has its local electric codes. The contractors must follow them.
You must also be aware of the codes to understand whether the contractors are doing work according to the regulations mentioned in the codes or not.
Suppose the contractors don’t follow the correct rules and regulations. In that case, you will be the one suffering difficulties and paying hefty fines.
So, please verify that the contractors are doing their work accordingly.
The NEC code
Many states follow the NEC code because they want a standardized approach to electrical work.
However, there is no mention of the number of lights and outlets in the NEC code.
That is why some people do not follow the regulations of this code.
The code is also not mandated by the Federal Government.
The local code
Even if the NEC codes are not followed, the contractors must follow the local codes.
Besides, if the local codes differ from that of NEC, contractors go with the local codes.
You must be aware of both the codes to understand how the contractors are doing their work and what rules they are following.
If not the NEC codes, the contractors must prioritize the local codes.
The limited number of lights and outlets is 10-12.
However, it depends on the amount of load the circuit can handle.
It would be best to add outlets carrying 1.5 amps per outlet in the circuit. According to this, you may add 10 outlets and lights in a 20 amp circuit.
However, it can be either less or more.
Rating of the circuit
The rating of the circuit is the same as the 15 amp circuit, i.e., 80%.
The circuit’s rating should not exceed 80%.
If that happens, the breaker will get overloaded and keep tripping.
In that case, you will have to change the whole circuit with the outlets and lights.
Leave 20% of the circuit rating to let the process go safely and avoid accidents.
With the 80% regulation, your 20 amp circuit will handle 16 amps.
According to that, you can install 10 outlets and lights.
How many lights can you run in a 20 amp circuit?
If you add only lights in a 20 amp circuit, ensure that the circuit installed is not a dedicated circuit where you can run only a certain appliance.
Adding lights to such a dedicated circuit means you are violating the law.
Other 20 amp circuits are fine to add lights as the current drawn will be within the rating and load.
Usually, you can run 40 lights, each of them having 50 watts of voltage.
It is enough to add in a 20 amp circuit with 120V.
If you have a 20 amp circuit having 240V, you can add 75 lights of 50 watts.
The 120V is better suited for residential applications.
The 240V is good for commercial applications like office buildings.
If you use a 60-watt LED light, you can put around 24 lights.
But if you use low-wattage lights, like around 10-watt LEDs, you can add 150 lights on a single circuit.
How many outlets can you put on a 20 amp circuit?
Keeping the 80% rated circuit load in mind, you can put up only 10 outlets in the 20 amp circuit.
10 outlets will run safely on this circuit.
You must ensure that the load capacity remains around 80% or less, but not more.
From one outlet, the maximum amps should be around 1.5 amps.
On that basis, the 20 amp circuit should not exceed 16 amps.
How to calculate?
The calculations are merely done by the experts who put up the circuit.
They will understand these things much more than we do.
But for a rough idea, we will share it with you.
In a 20 amp circuit, you are not allowed to exceed 80%.
If that happens, the circuit breaker will keep tripping due to overloading.
So the calculation is 20 amps x 0.8 = 16 amps.
So, in 20 amps, you get to use 16 amps full.
Now, one outlet is allowed to use only 1.5 amps of the circuit, which leads to a maximum of 80% usage.
According to that:
16 amps / 1.5 = 10.66 outlets
So, you get to use 10 outlets per 20 amp circuit.
Can I add more than 10 outlets in a 20 amp circuit?
If you add more than 10 outlets, the breaker will keep tripping, and you will receive a fuse blow.
If you want to put up 12 outlets, it is better to install two 20 amp circuits and put up 6 outlets in each of the circuits.
This split-up will give you more expansion capacity in the circuits you may need in the future.
What else can I run in a 20 amp circuit?
A 20 amp circuit is not for heavy appliances like stores, washing machines, dryers, or refrigerators.
As you have read, they will tolerate only 80% of ratings.
However, a 20 amp circuit is used in both residential and commercial buildings for only lights and outlets.
You can attach only 10-12 devices with fewer currents in the outlets.
However, there are some devices you can connect to the 20 amp circuits.
In some circumstances, you may sometimes allow the circuit to overload, provided you use extender plugs.
But, it is better not to take the risk as it can blow a fuse.
Appliances like dishwashers and electric stoves must have separate circuits as they use loads of electricity in the kitchen.
The same goes for the laundry room and bathroom.
Where can I put lights and outlets in the 20 amp circuit together?
The kitchen and laundry rooms are spots where you should not use lights and outlets in the same circuit.
But in some rooms, you can keep them in the same circuit:
In the bedrooms, we need very few lights. 4-8 lights should be enough in a bedroom.
If you use 60-75 wattages for 20 amp circuits, you can put up 8 lights without any problem.
3-5 or 3 double outlets should be enough in a bedroom to put up such 4-8 lights.
For a medium bedroom, you can use 4 lights; for large rooms, 8 is enough.
Another reason you can add lights and outlets in a 20 amp circuit in the bedroom is the light’s consumption power.
Lights utilize a very small amount of power.
So, there are no chances of overload in the circuits.
Generally, a 15 amp circuit is enough for bathrooms.
But, if your bathroom has a fan and a heater, you should opt for 20 amp circuits.
You can even add the lights and outlets in the same circuit.
Ensure the circuit does not serve any other outlets outside the bathroom.
How to understand that your circuit is overloaded?
When a 20 amp circuit is overloaded, it will have some signs for which the problem is easy to solve.
If lights are connected to an overloaded circuit, the lights will keep flickering.
You will also get a burning smell or a buzzing sound from the room where the circuit is installed.
If your circuit is overloaded, the outlets will become discolored.
Outlets used for a long time can get discolored, which is normal.
But the new outlets getting discolored is a sign of overloading.
Sometimes, you may receive slight electrical shocks while dealing with the circuits.
So, whenever you find signs of overloading, switch off the main fuse, replace the circuits, and put up only a limited number of outlets and lights that stay within 80% rated load.
NEC codes did not mention the number of lights and outlets to be added in a 20 amp circuit, but the limit is 10. The maximum you can add is 12 lights and outlets but not more than that. However, NEC recommends 10.
Adding 10 outlets and lights allows the circuit rating to be within 80%. Each outlet will have 1.5 amps. You can add 8 outlets and 2 lights.
Do follow the rules and regulations of both NEC and local codes. If the NEC codes differ from the local codes, the contractors must follow the local codes.
It is safe to add lights and outlets in the same circuit, but it is better not to use them together. You must change the whole circuit along with the lights and outlets if accidents happen.
What is a dedicated circuit?
A dedicated circuit is a circuit used for only a single appliance.
You cannot put up any other device in that circuit.
If you do so, there will be overloading and cause the fuse to blow up.
Only heavy-duty appliances are used in the dedicated circuits.
What size of wire do you need for a 20 amp circuit?
A 12-gauge wire is enough for a 20 amp circuit, either 110 or 220V.
There will be no neutral wires but two hot wires, red and black, and one ground wire.