Voltage Drop: 115V equipment on 120V power

[Jon456]

Create a realistic example.

But you're the one injecting absolutes into the example. It was realistic if one were to understand that I was talking about a realistic piece of equipment with a 120V nameplate rating and a realistic maximum branch circuit voltage drop of 3%.

Let's not argue semantics for the sake of creating discourse and "gotcha's." I'm trying to solve a real-world problem.

 

[gar]

190704-2331 EDT

Jon456:

If you are trying to solve a real world problem, then figure out how to clearly define and ask the question.

I believe that today most US tungsten incandescent light bulbs are labeled as 120 V and X watts. In other words their rating. What does that mean? Probably about a life of 700 to 1000 hours on average at 120 V, and will be quite close to the marked wattage at the marked voltage. Will this bulb work at 60 V? Yes. How long will this bulb last at 60 V? Probably a very long time.

Connect this bulb to a long, 1000 ft, #14 extension cord. Suppose X is 100 W, and the input to the cord is held at 120 V. What is the approximate voltage at the bulb? Will the bulb last longer or shorter on average? What is the approximate voltage drop at the bulb?

Drop the source voltage down to 100 V and answer the same questions.

Define any assumptions you make, and show how you get your answers?

Note that a tungsten light bulb is not a constant average resistance as you change its applied voltage.

.