How many 75 watt bulbs can be on a 15 amp circuit?

Answer 1

This type of question usually means you aren't ready to do this yourself. Study some electrical material and the National Electrical Code and work this answer out for yourself. If I were to give you an answer, you might attempt to do something you shouldn't be doing, and that may cost someone a shock, a home fire, or their life.

Answer 2

You can have up to 10 75-watt bulbs on a 15 amp circuit. Each 75-watt bulb consumes 0.625 amps (75 watts divided by 120 volts), so 10 bulbs would consume 6.25 amps, which is under the 15 amp limit for the circuit.

Answer 3

Add up the bulbs and you will have the total wattage for that circuit. Let's say it is a typical 120Vac household circuit.

15 amps is the maximum that circuit will handle. Current (amps) is calculated by:

I = Power (wattage) / Volts, so for example:

I = (10) 100 watt light bulbs / 120

Current = 1000/120 = 8.3 amps, You are safe,

In reverse, to figure out how many bulbs you can have:

Multiply the bulb wattage by the number of bulbs you have (on an individual crkt). This cannot exceed 1800.

1800 is the total wattage allowed for a 15 amp, 120V circuit.

The same is true for any device used on a circuit. Toaster, radio, etc. The wattages will be listed on the device.

Is your circuit a temporary "work site" type bulb stringer?

Answer 4

The math is simple. Watts = Volts * Amps

In this case Amps are fixed, at 15, and you want to know the total wattage that can be drawn by all the appliances you add to the circuit.

So the answer depends on the voltage. Voltage can be anything, but there are some commonly used domestic supply values:

For 220 volts, 220*15 = 3300watts

For 110 volts, 110*15 = 1760watts

For 240 volts, 240*15 = 3600watts

Answer 5

Assuming a standard incandescent bulb with a 120 VAC supply it is 19. Now there are other factors that you need to make sure of like the rating of the fixtures. For example you could size for 75W bulbs but someone might decide to go to 100 W in the future.

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The way we get to 19 is that each will draw about .625 amps. We need to divide this into the breaker rating, but only at 80% of capacity for a continuous load. So we have 12 / .625 giving 19.2 as result.

The key formula is Watts = Volts x Amps.

Answer 6

Answer for UK, Europe and countries running a 50 Hz supply service.

If you have a 240 v supply and you use 20-watt ceiling lamps, you can have about a hundred on a standard 10-amp lighting circuit.

Answer 7

Depends on the wattage of each light and if ONLY lights will be on the circuit and no outlets. On a 15 amp circuit at 120 volts it is rated at 1800 watts. But the NEC restricts you to only a load of 80% of the circuit so that means you can only load the circuit to 1440 watts. Assuming you are installing 75 watt can lights you can install 19 can lights. Install 65 watt can lights and you can install up to 22 can lights. But if you installed fluorescent can lights pulling 14 watts each you can install 102 lights. Install 15 watt LED bulbs and you can install 96. You will have line voltage loss so be aware of that on any long run. The fact is that someone could come along and remove the fluorescent or LED bulbs and install regular bulbs. So my advice is to assume each light to be a 75 watt light and limit the circuit to no more than 19 lights.

Answer 8

15 amps at 80% = 12 amps continuous. Watts = Amps x Volts.

Answer 9

12