240 or 120 Volt?

[BobRip]

And current is amps.

I x I x R

is the SAME as

Amps x Amps x ohms

Yet you say Amps x Amps x Ohms is wrong, and I x I x R is correct???

They are both correct. The incorrect part was that there is only one equation for watts. Sorry for the confusion.

 

[LD1]

You are mostly correct, except the first line. Watts does NOT equal ohms times amps times amps. Watts is simply volts times amps.

Not correct. Power can be calculate several ways
P = V X I
P = I X I X R
P = V X V / R

Look it up.

I guess the way you worded this is what was confusing.

You said "watts does NOT equal ohms times amps times amps"....

And then you said...

"P=I X I X R"

:confused2::confused2:

 

[BobRip]

I guess the way you worded this is what was confusing.

You said "watts does NOT equal ohms times amps times amps"....

And then you said...

"P=I X I X R"

:confused2::confused2:

Sorry for the confusion. The iPad can be difficult to edit reply quotes. My bad.

 

[LD1]

You are forgiven

 

[JD 4520]

LD1 - Q: on a typical 120V line in my house, what is the lowest voltage level that I should have to avoid any concerns? Here is the situation. I was operating an air compressor pitied and I plugged in my volt meter to the same outlet and had a reading of 109V. I am curious how low I can go without being concerned.

 

[grsthegreat]

LD1 - Q: on a typical 120V line in my house, what is the lowest voltage level that I should have to avoid any concerns? Here is the situation. I was operating an air compressor pitied and I plugged in my volt meter to the same outlet and had a reading of 109V. I am curious how low I can go without being concerned.

Im not LD1 but we (electricians) try and keep voltage drop to a maximum 5% loss at the end of a run, and preferably no more than 3%. A 120 volt circuit with a 5% drop equates to 114 volts. Did you check the voltage at the panel ??? I have actually seen houses with 109-110 volts at the main panel, so any voltage drop equates to more than 5% from the norm power.

 

[JD 4520]

This particular line is one of the farthest from my panel and the test I referenced was at that same outlet. From what you said I presume that I would not have such a drop on that same circuit at the panel but something to test. Thank you for your reply.

 

[grsthegreat]

This particular line is one of the farthest from my panel and the test I referenced was at that same outlet. From what you said I presume that I would not have such a drop on that same circuit at the panel but something to test. Thank you for your reply.

You should test the main panel and then you can determine the % of voltage drop. If its too great, you need to run some heavier wire. (DONT increase the breaker size, that wont do anything and is dangerous. Only larger wire size will help.

 

[JD 4520]

Excellent. I'm on it. I love this stuff just wish I knew a little more but slowly learning.

 

[LD1]

Well, it seems you have had your question already answered.

Disclaimer: I am not an electrician. I just know enough to be dangerous:laughing: But I have a good understanding of electrical and residential wiring, enough to tackel anything I need, but again, I am not an electrician.


I was going to say 115V minimum, but you already got that answer.

There are a coouple of things that could be causing you issues. First (and you say you are on it) is to check what you have at the MAIN panel. It could be low from the get-go. My mains are usually 121-122V:thumbsup:

Second, you probabally have TOO long of a run with TOO small wire. 12ga is the standard for 20A circuits. BUT, when you start to go over 100ft, the voltage drops is what gets ya.

I am not sure of your lay-out, but you say this is the farthest outlet, is their a MAIN 240v panel in that building, or only a 120 line running to it? May need to upgrade and put a panel in that building. Just thinking out loud.