 |
|
12-20-2007, 09:56 AM
|
#1
|
|
Registered User
Trade:
electrician
Join Date: Dec 2007
Posts: 4
|
how important is ohm's law in the real world
i was wondering is ohm's law important when working or is it just another school formality.
|
|
|
Warning: The topics covered on this site include activities in which there exists the potential for serious injury
or death. ContractorTalk.com DOES NOT guarantee the accuracy or completeness of any information contained on this site. Always use proper safety precaution and reference reliable outside sources before attempting any construction or remodeling task!
Join the #1 Contractor Forum Today - It's Totally Free!
ContractorTalk.com - Are you a Professional Contractor? If so we invite you to join our community and see what it has to offer. Our site is specifically designed for you and it's the leading place for contractors to meet online. No homeowners asking DIY questions. Just fellow tradesmen who enjoy talking about their business, their trade, and anything else that comes up. No matter what your trade is you'll find that ContractorTalk.com is a great community to join. Best of all it's totally free!
Join ContractorTalk.com - Click Here

|
12-20-2007, 10:00 AM
|
#2
|
|
New Guy
Trade:
Super Electrician
Join Date: Dec 2007
Posts: 13
|
Quote:
Originally Posted by pennco tech
i was wondering is ohm's law important when working or is it just another school formality.
|
You'll use it often to calculate wire size and loads. It's very common to add up connected loads in Watts and convert to amps at various voltages for panel and breaker sizing.
|
|
|
12-20-2007, 12:24 PM
|
#3
|
|
Registered User
Trade:
electrician
Join Date: Dec 2007
Posts: 4
|
thanx
thanx for your help
|
|
|
12-20-2007, 05:45 PM
|
#4
|
|
Professional Remodeler
Trade:
Remodeling Contractor
Join Date: Dec 2005
Location: Southeast Michigan
Posts: 2,290
|
If your going to do electrical work, that is one law that you probably will use often. Learn it - Know It
__________________
 -Mike-
Falcon Contracting Residential - Commercial
|
|
|
12-20-2007, 06:41 PM
|
#5
|
|
Electrician
Trade:
Electrical Contractor
Join Date: Jul 2007
Location: Central Wisconsin
Posts: 265
|
Quote:
Originally Posted by pennco tech
i was wondering is ohm's law important when working or is it just another school formality.
|
Extremely important. Used often.
|
|
|
12-20-2007, 09:24 PM
|
#6
|
|
God Bless America
Trade:
Electrician
Join Date: Dec 2006
Location: Rahway, New Jersey
Posts: 3,400
|
Suppose you had to install a 10 horsepower 1ø motor for an exhaust fan and it was a 100' away from a power source. Would you A) operate the motor at 115 volts (100 amps), or B) operate the motor at 230 volts (50 amps)? The wattage would be the same for both applications.
In the first example you'll need to run #3 copper, the second, #8 copper.
One cost twice as much (or close to it) than the other one does.
Ultimately, this is an example of Ohm's law and why it'll be very important to know it later on.
Good luck!
|
|
|
12-20-2007, 09:28 PM
|
#7
|
|
DGR,IABD
Trade:
Electrical; Commercial and Residential Service
Join Date: Mar 2005
Location: Central PA
Posts: 9,665
|
Quote:
Originally Posted by pennco tech
i was wondering is ohm's law important when working or is it just another school formality.
|
It's far from a formality. It's the basic set of formulas that all electrical work is based on. It will become second-nature to you in time.
|
|
|
12-20-2007, 09:46 PM
|
#8
|
|
God Bless America
Trade:
Electrician
Join Date: Dec 2006
Location: Rahway, New Jersey
Posts: 3,400
|
R stands for resistance measured in ohms
I stands for current measured in amperes
E stands for voltage measured in volts
P stands for power measured in watts
|
|
|
12-20-2007, 09:48 PM
|
#9
|
|
Celtic's #1 Fan
Trade:
electrical
Join Date: Aug 2006
Posts: 2,387
|
ahh...it's useless these days..don't worry about it...
|
|
|
12-20-2007, 10:43 PM
|
#10
|
|
Pro
Trade:
Union Electrician
Join Date: Oct 2007
Location: Chicago
Posts: 135
|
Right, that is why the American Federation of Scientific Researchers voted overwhelmingly to rename it Ohm's suggestion.
|
|
|
12-21-2007, 05:53 AM
|
#11
|
|
Pro
Trade:
General Contractor
Join Date: Mar 2006
Location: Hennessey, Oklahoma
Posts: 4,570
|
Quote:
Originally Posted by Magnettica
R stands for resistance measured in ohms
I stands for current measured in amperes
E stands for voltage measured in volts
P stands for power measured in watts

|
Nice chart, all I learned in tech school was P/IxE and E/IxR.
__________________
Ladwig Construction Hennessey, Oklahoma 405 853 1563
Ladwig Insulation & Construction Services Serving Oklahoma Statewide 405 314 5802
|
|
|
12-21-2007, 06:56 AM
|
#12
|
|
Celtic's #1 Fan
Trade:
electrical
Join Date: Aug 2006
Posts: 2,387
|
Quote:
Originally Posted by goose134
Right, that is why the American Federation of Scientific Researchers voted overwhelmingly to rename it Ohm's suggestion.
|
that was my idea
|
|
|
12-21-2007, 11:18 PM
|
#13
|
|
Pro
Trade:
Master Electrican, Electrical Contractor
Join Date: Sep 2005
Posts: 329
|
Quote:
Originally Posted by goose134
Right, that is why the American Federation of Scientific Researchers voted overwhelmingly to rename it Ohm's suggestion.
|
Ohms nudge and a wink eh? Nudge and a wink.
|
|
|
12-23-2007, 08:35 PM
|
#14
|
|
New Guy
Trade:
Electrical & General Contracting
Join Date: May 2007
Location: Ontario
Posts: 28
|
Quote:
Originally Posted by pennco tech
i was wondering is ohm's law important when working or is it just another school formality.
|
Are you really an electrician?
|
|
|
12-24-2007, 07:28 AM
|
#15
|
|
Baltimore Electrician
Trade:
Electrician
Join Date: Jan 2007
Location: Baltimore, MD
Posts: 1,199
|
It is so important, we wear it on our wrists....
http://www.technotetime.com/items/al...tance/list.htm
Actually, I don't wear mine at work, because it was a gift, and it's metal
Lots of neat stuff on that site.
__________________
John from Baltimore
"One Day at a Time"
All replies based on the 2008 NEC
Quote:
|
Originally Posted by celtic
Deny Everything, Admit Nothing, Demand Proof
|
|
|
|
04-06-2008, 03:17 PM
|
#16
|
|
Pro
Trade:
contracts/negotiations
Join Date: Nov 2007
Posts: 170
|
Probably not so important for electrical wiring technician / electrician who just knows how to hook up wires based on reference manual without a knowledge of why.
|
|
|
04-06-2008, 05:57 PM
|
#17
|
|
Pro
Trade:
General Contractor
Join Date: Mar 2006
Location: Hennessey, Oklahoma
Posts: 4,570
|
Quote:
Originally Posted by Electric_Light
Probably not so important for electrical wiring technician / electrician who just knows how to hook up wires based on reference manual without a knowledge of why.
|
I am not an electrician, but I do believe anyone specializing in a trade should know the theory along with the practical....I trained a lot of aircraft mechanics who would be working on jet engines and we still taught the basics of thermal dynamics and ratios....so they would understand how a fuel control actually made an engine work...kind of like knowing the electron theory and current theory would be important to a true electrician.
__________________
Ladwig Construction Hennessey, Oklahoma 405 853 1563
Ladwig Insulation & Construction Services Serving Oklahoma Statewide 405 314 5802
|
|
|
04-06-2008, 06:02 PM
|
#18
|
|
Handle It!
Trade:
Everything The Union Guys Do Not Want To Do
Join Date: Feb 2008
Location: Brooklyn, NY ~ Haverford, PA
Posts: 7,901
|
Quote:
Originally Posted by macmikeman
Ohms nudge and a wink eh? Nudge and a wink.
|
http://www.youtube.com/watch?v=zVJOP1RdHC4
Last edited by MALCO.New.York; 04-06-2008 at 06:05 PM.
|
|
|
04-06-2008, 06:14 PM
|
#19
|
|
Pro
Trade:
Squirrel Handler
Join Date: May 2006
Location: Chicago
Posts: 3,438
|
Quote:
Originally Posted by pennco tech
how important is ohm's law in the real world
i was wondering is ohm's law important when working or is it just another school formality.
|
Extremely important get it tattooed on your body, preferably where you can see it.
__________________
Some people climb mountains. I take out the trash. But we both do it for the same reason.
|
|
|
04-09-2008, 03:02 PM
|
#20
|
|
Pro
Trade:
sparky
Join Date: Jan 2008
Location: SW Michigan
Posts: 591
|
I though it would be a good idea for all apprentices to have it tattood on their foreheads in a mirror image so they can look in the mirror and be able to read it.
higher powers didn't accept my proposal.
|
|
|
| Thread Tools |
Search this Thread |
|
|
|
| Display Modes |
Rate This Thread |
Linear Mode
|
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is Off
|
|
|
|
|