Campground Breakers - EDITED

DownTheAvenue wrote:

DrewE wrote:

DownTheAvenue wrote:

DrewE wrote:
(Incidentally, the suggestion that current always goes up when voltage goes down is absolutely incorrect for many loads. Electric motors and motor-driven equipment is a rather complicated case; the current may go up, down, or stay the same, at least within some reasonable range of voltages. If the voltage drops low enough, the current will of necessity go down; otherwise you'd have the air conditioner etc. consuming inifinte current when unplugged with the generator off! For resistance heaters and incandescent lights, the current (and hence power consumed) drops as voltage drops.)

In other words, Ohm's Law is not a fact. WOW! I did not know that. Thanks for posting this new relevation!

Ohm's law is a description of how many, but certainly not all, things behave electrically. Ideal resistors follow Ohm's law; practical physical resistors (including such things as wires and fuses) come very close indeed to the ideal, over a wide range of voltages and currents. Of course, for things that follow Ohm's law, the current is proportional to the applied voltage, and so goes down as the voltage drops.

Things like semiconductors and motors under load and incandescent lights are not ohmic, some very much so, and for them the relation of current to voltage is different and generally more complicated. Ohm's law can still be used in some circumstances as a handy analysis tool, perhaps only under fairly closely defined circumstances. In other words, it's still useful at times to treat such non-ohmic things as their equivalent resistances at some specified operating conditions.

I am not an electrical engineer, are you? However, I have several advanced degrees and did do a little study about what you posted, as well as removing a few cob webs from my brain where I did study the science and physics of electricity obtaining an advanced degree, and I cannot support anything you posted. I would appreciate your citing sources so I can better educate myself. Without any citations, I have to assume you are merely an armchair critic without any qualifications.

I'm in the same boat as you, however I am an electrical engineer, have my PE in 12 states, have been practicing for 39 years, and have dealt with 100's, if not 1000's of induction motors, and his statements are pretty much all wrong. I decided not to post and see if others stepped up, which they have. Ohms law is not a guide or suggestion, just like a speed limit is not a suggestion. In addition, the power of a motor is P=V*I. No resistance there. In addition, every, and I mean every circuit can be broken down into a Thevenin(sp) equivalent, where Ohms law applies. In fact, I have taught a course on motors, and motor design and maintenance a few years back. So I have a bit of experience here...

Al