How many lamps can be in a 15 amp circuit (calculator)

Content

15 amp circuit calculator
Introduction - Mathematics
Incandescent, CFL and LED lamps
How many light bulbs can be installed in a 15 amp circuit
- Incandescent lamps
CFL lamps
- LED lamp

This is a simple question that can be very confusing. There is no definitive answer, as the number of bulbs in a 15 amp circuit will vary depending on the bulb type, bulb wattage, and circuit breaker type.

When upgrading a lighting system in a home, one of the first thoughts should be the number of lights the scheme can handle. Each house or building may have a different amperage in the circuit, but the most common is the 15 amp circuit. In this article, I will explain how many light bulbs can fit in a 15 amp circuit depending on the type of bulb.

If you are using incandescent bulbs, you can use 14 to 57 of them. If you are using CFL bulbs, you can fit 34 to 130, and when installing 84 to 192 LED bulbs. These figures refer to the minimum and maximum power. Incandescent lamps consume no more than 100 watts, LED - up to 17 watts, and CFLs - up to 42 watts.

15 amp circuit calculator

The range of light bulbs you can put in a 15 amp circuit is between and light bulbs.

Here is a table of the number of light bulbs you can put in a 15 amp 120 volt circuit based on wattage:

POWER	Number of bulbs
60 W	24 light bulbs
40 W	36 light bulbs
25 W	57 light bulbs
15 W	96 light bulbs

I'll go into more detail below.

Introduction - Mathematics

All circuits are designed to handle a certain amount of current, sometimes more than what they are designed to handle (for example, a 15 amp circuit can handle more than 15 amps of current).

However, electrical circuit breakers limit the power of a circuit to protect it from unexpected power surges. Thus, to avoid tripping the circuit breaker, the "80% Rule" should be followed.

Multiplying 15 amps by 80% gives us 12 amps, which is the circuit's maximum capacitance at 15 amps.

Incandescent, CFL and LED lamps

The most common types of lamps are incandescent, CFL and LED.

The main difference between them lies in the thermal energy. LED light bulbs do not generate heat, so much less energy is required to produce the same amount of light as incandescent and CFL bulbs.

So, if you are planning to install a lot of light bulbs on a 15 amp circuit breaker, the best option is to install LED bulbs.

How many light bulbs can be installed in a 15 amp circuit

Each of the three categories offers a different degree of effectiveness.

This means that 15 amp circuits and 15 amp circuit breakers can handle different numbers of incandescent, LED and compact fluorescent lamps.

For calculations, I will use the maximum and minimum power of each type of lamp. This way you will know the range of light bulbs that can be installed in a 15 amp circuit.

Let's count.

Incandescent lamps

As mentioned above, incandescent light bulbs require much more energy than other light bulbs. This means you can install fewer incandescent bulbs than CFLs and LEDs.

The minimum power of incandescent lamps is 25 watts.

The maximum current flowing through the circuit is 12 amps (according to the 80% rule). So after doing the math, we get: Power equals voltage times current:

P=V*I=120V*12A=1440W

Now, to calculate how many light bulbs you will use, I need to divide the wattage of the circuit by the wattage of one light bulb:

1440W / 25W = 57.6 bulbs

Since you can't fit 0.6 bulbs, I'll round up to 57.

Maximum power 100W

The maximum current will remain the same, i.e. 12 amps. Thus, the power of the circuit will also remain the same, i.e. 1440 watts.

Dividing the power of the circuit by the power of one light bulb, I get:

1440W / 100W = 14.4 bulbs

Since you can't use 0.4 bulbs, I'll round up to 14.

So the range of incandescent bulbs you can plug into a 15 amp circuit will be between 14 and 57.

CFL lamps

The power of CFL lamps ranges from 11 to 42 watts.

Maximum power 42 watts.

The maximum current of the electrical system will remain the same as that of incandescent lamps, i.e. 12 amperes. Thus, the power of the circuit will also remain the same, i.e. 1440 watts.

Dividing the power of the circuit by the power of one light bulb, I get:

1440W / 42W = 34.28 bulbs

Since you can't use 0.28 bulbs, I'll round up to 34.

Minimum power 11 watts.

Dividing the power of the circuit by the power of one light bulb, I get:

1440W / 11W = 130.9 bulbs

Since you can't use 0.9 bulbs, I'll round up to 130.

So the range of incandescent bulbs you can plug into a 15 amp circuit will be between 34 and 130.

LED lamp

The power of LED lamps varies from 7.5W to 17W.

I'll start with the maximum power, which is 17 watts.

The maximum current of the electrical system will remain the same as that of incandescent lamps and CFLs, that is, 12 amperes. Thus, the power of the circuit will also remain the same, i.e. 1440 watts.

Dividing the power of the circuit by the power of one light bulb, I get:

1440W / 17W = 84.7 bulbs

Since you can't fit 0.7 bulbs, I'll round up to 84.