Home circuits are built to work with a specific electrical load while maintaining certain safety levels. Even though lighting appears not to take up too much energy, it is surprising on the load when you have multiple lights on a single circuit. So, knowing how many lights on a 15 amp circuit breaker is a more common question than you may expect.
The wattage of lights will determine the number of lights that run on a 15-Amp circuit. The total amperage drawn by the circuit’s lights must not exceed 80% of the circuit breaker’s rated capacity. When deciding on this, you’ll find how many LED lights on a 15 amp circuit can exceed the number of regular bulbs before overload.
The max for conventional light fixture will be a maximum of 12-Amps for a 15-Amp circuit breaker, and thus as a quick example, using a 60 watt light, a 15 amp breaker can deliver safe power for up to 24 lights. You can install up to 150 LED lights on a single circuit if you use low-wattage LED bulbs, such as a 10 watt LED bulb. Maintaining the proper load on a circuit is essential for most homeowners’ safety.
In our guide, you can learn more about DIY electrical work and adding receptacles and lighting circuits. By the end, you’ll know how to calculate the current draw and how any future wired lighting circuits won’t overload the same circuit once you start adding outlets for lights or switches. (Learn How Many Outlets On A 20 Amp Circuit)
How Many 100 Watt Bulbs Can Be On A 15 Amp Circuit?
Before adding light fixtures and outlets for a new appliance, you need to know the current draw and the likely draw.
Using a light bulb as an example, you can use a formula to determine how many 100-Watt lightbulbs you can install on a circuit to remain inside limits stated by the wiring code.
100 Watt Light Bulbs:
Amps = 100-Watts / 120-Volts
Amps = 0.833
75 Watt Light Bulb Fixtures
The current drawn by a 75-watt lamp is 0.625 amps. To figure out how many lights we can put on the circuit, divide the 12-Amp restriction by the light’s amperage.
12-Amps / 0.833-Amps
= 14.4 of the 100-Watt Lights
Our formula shows you can install a maximum of 14 lights rated at 100-Watt and remain within the 80% limitation of a 15-Amp circuit breaker.
Tips For Installed Receptacles, Switches, and Circuit Loading
You can add as many outlets as you like to a 15-amp circuit, but the number of appliances you can connect into those outlets must be limited. The breaker will trip if you exceed the circuit’s rating.
During certain seasons, strong appliances that take a lot of electricity, such as heaters, should be connected to circuits with the fewest receptacles. It’s less likely that the circuit will be overloaded.
While it has drawbacks, it is sometimes recommended that outlets and lights be connected to the same circuit. This is because lights consume very little energy. In addition, this allows you to distribute power usage across your electrical panel’s multiple breakers.
Consider putting powerful appliances, such as washers, on dedicated circuits, so they don’t have to compete with other appliances. This also lowers the likelihood that the circuit becomes overloaded. (Read Ground Wire Size Chart)
Make sure you have outlets all over the house. Don’t put all of them in one place. This makes electricity more accessible and eliminates the need for power extensions.
Power strips and extensions are only temporary fixes. They’re linked to a slew of dangers, so, it’s better to increase the number of outlets in your home.
How Many 13-Watt Lights Can Be On A 15 amp Circuit?
The rating for lights is in Watts, whereas the value for circuit breakers is in Amps. Therefore, you must convert the lights’ Watts to the same unit of measure as the circuit breaker to set the circuit’s restrictions.
Because light wattage mixes voltage and amperage, you can determine this limit using a simple equation. The voltage used in most homes is 120 volts; however, if your home is different, you must substitute your voltage where 120 volts is used in the equation.
Watts are calculated using the formula Watts = Amps X Volts. Use the following formula to acquire the Amps by reversing the formula.
Watts / Volts = Amps
Plug the variables into the equation to see how many amps a 60-Watt light bulb will draw.
60 Watts x 120 Volts Equals Amps
A 60-watt lamp will draw 0.5 amps, according to our calculations. This calculation can determine whether we are within the 80 percent capacity of the circuit breaker for each of our light circuits or if we need to create a brand new circuit to add extra lights to our home.
How Many Can Lights On A Single Circuit?
Your home’s electrical circuits can only withstand so much power. So outlets with similar demand share a circuit.
Just as electricians put electrical outlets together, homeowners can group lights on a separate circuit. (Read Ground Wire Size Chart)
The number of lights you can run on a circuit depends on the circuit breaker’s rating, the wire’s thickness or gauge, and the lights’ energy requirements.
The gauge of wire used by homebuilders varies per circuit. For example, the lighting circuit employs 14-gauge wire, lighter than electrical outlets. On the other hand, circuits requiring a 20-Amp breaker often employ 12 to 10-gauge copper wire.
Too much current or amperage in a wire causes it to heat up. The narrower the wire, the faster it heats up when overloaded.
Most local wiring codes follow the National Electrical Code (NEC) with minor variations. For example, the NEC says that a circuit breaker’s load shall not exceed 80%.
This means that with a 15-Amp circuit breaker, no more than 12-Amps can flow across the circuit at any moment. Therefore, a 15-Amp circuit can have any number of light fixtures on it.
You’ll still be breaking the wiring code if all those lights are on at the same time and the current surpasses 12Amps
Install only the number of light fittings and globe wattage on the circuit that would keep the 80 percent constraint if all the lights were on simultaneously.
What About Mixed Wattage Lights?
Because we don’t all have the same wattage lights in our homes, you’ll need to collect data for each light on the circuit. Therefore, you must first determine the Watts of each light on the circuit, then calculate the amps used by each light, and finally combine the amps.
The total Amps used by the lights on the circuit must not exceed the 15-Amp circuit breaker’s 12-Amp limit.
If you have 2 x 60-Watt lights, 5 x 75-Watt lights, and 3 x 100-Watt lights on the same 15-Amp circuit, your computation might look like this:
- 1 x 60-Watt = 0.5-Amps, so 2 lights use 2 x 0.5-Amps = 1-Amp
- 1 x 75-Watt = 0.625-Amps, so 5 lights use 5 x 0.625 = 3.125- Amps
- 1 x 100-Watt = 0.833-Amps, so 3 lights use 3 x 0.833 = 2.5-Amps
We get the following result when we total up the current for all the lights.
Total Amps: 1-Amp + 3.125-Amps + 2.5-Amps = 6.625-Amps
According to our calculations, our total of 6.625 amps is still significantly below the 12-amps allowed on the circuit.
How Many Lights and Lighting Outlets On a 15 Amp Circuit?
A 15-amp circuit may accommodate an unlimited number of outlets and lights. You should not, however, exceed the circuit’s rating.
More significantly, you should not increase a load that exceeds the circuit’s maximum capacity by more than 80%.
The answer here means you need to consider a few factors.
Regulations and Electrical Code
Like everything else, you must follow the rules. Each location has its own electrical code that contractors must follow while installing electrical systems. Infractions of the law may result in heavy fines.
First, verify the National Electrical Code and even the local code. The NEC doesn’t stipulate how many outlets and lights a 15 amp circuit can have.
You can install as many lights and outlets as you wish in your house. However, your local government may have regulations governing this. Consult them first for your location.
The receptacles’ ratings must match the circuit’s max rating. This shows the circuit’s max receptacle number.
The average lamp or outlet gets 1.5 amps. With that in mind, a 15-amp circuit you can plug into can theoretically support ten lights and outlets.
The NEC doesn’t specify how many lights or outlets can be added to a circuit at a number. But it includes rules that may influence your decision in this area. For example, the NEC wants contractors to count only 80% of the circuit’s rating.
A circuit breaker cannot be forced to carry more than 80% of its rated load. So, for example, a 15-amp circuit can only count 12 amps.
So, what? This circuit can support eight outlets and lights. The goal is to provide the circuit enough room to handle a transient spike caused by large power-consuming equipment. (Read Wire Size For 100 Amp Service 150 Feet)
With all these calculations, you may ask how many lights on a 20-amp circuit.
Here are brief examples:
- 30 lights (50-watt light) on a 15 amp breaker.
- 40 lights (50-watt light) on a 20 amp breaker.
Here’s more material about the total number of fixtures rather than bulbs.
- The total wattage of all fixtures (appliance connection) on any circuit is 1800 watts for 15 amps and 2400 watts for 20 amps.
- Second, how much current do recessed lights use? A standard density 3528 LED light strip draws twenty-four watts, divided by twelve equals two amps.
- A 15-amp circuit electrical panel may handle a maximum wattage of up to 1440 watts (15 × 8 x 120 = 1440). If you add a receptacle to a lighting circuit, you are back to the 12 device count.
- There are different gauge wires for any wired lighting circuit or one catering to appliances, so you need to ensure you use the correct gauge for your outlet receptacles or light socket.