How To Figure Amps On A Circuit? - Electrical - DIY Chatroom Home Improvement Forum

Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Electrical


Thread Tools Display Modes
Old 01-22-2010, 01:31 AM   #1
Join Date: Jan 2010
Location: vancouver, BC, Canada
Posts: 124
Rewards Points: 97

how to figure amps on a circuit?

I have a friend who has a breaker that keeps tripping in his home panel. I dont have a clamp on meter. How do you figure out how many amps are on the circuit?


bcbud3 is offline   Reply With Quote
Old 01-22-2010, 05:47 AM   #2
Join Date: Dec 2009
Posts: 1
Rewards Points: 10

buy a clamp on meter?


SolidAxleDurang is offline   Reply With Quote
Old 01-22-2010, 06:21 AM   #3
Join Date: Aug 2009
Location: Maryland
Posts: 61
Rewards Points: 75

Without a clamp-on ammeter, you might try sequentially disconnecting or turning off and on items served by that breaker and observing the breaker action. That way you can compute the load.
oilseal is offline   Reply With Quote
Old 01-22-2010, 10:00 AM   #4
Electrical Contractor
jbfan's Avatar
Join Date: Jun 2004
Location: Newnan GA
Posts: 6,979
Rewards Points: 554

without a meter you can only guess.
What size and type of breaker?
Could be a gcfi that is tripping on ground fault and not over current. The same with a AFCI breaker.
Need more details!
"The problem isn't that Hillary Clinton lies. We all know she lies. The problem is that her supporters don't seem to care"
jbfan is offline   Reply With Quote
Old 01-22-2010, 10:02 AM   #5
Join Date: Nov 2007
Location: Nashua, NH, USA
Posts: 7,968
Rewards Points: 1,542

Add up the watts of the things plugged in and turned on for that circuit and divide by 120 (by the volts).

Is it only when something that uses a lot of electricity, such as a hair dryer, is turned on?

Sometimes one circuit serves two or three rooms so you might be surprised how many items you find are drawing power from that circuit.
The good conscientious technician or serviceperson will carry extra oils and lubricants in case the new pump did not come with oil or the oil was accidentally spilled, so the service call can be completed without an extra visit.

Last edited by AllanJ; 01-22-2010 at 10:05 AM.
AllanJ is offline   Reply With Quote
Old 01-22-2010, 12:11 PM   #6
Join Date: Sep 2008
Location: Oregon
Posts: 1,497
Rewards Points: 500

Yes, turn off the breaker, then see what no longer works.

List each item and write down the watts in one column if it says watts on the appliance or amps in another column if it says amps on the appliance label.

Then total the watts. Total the amps.

Here you can convert watts to amps under "single phase"...

Then add the amps converted from the watts column to the other amps total. And you have the total amps being used.

To solve the problem, you can move some of these to another circuit.

Or run a new circuit to one big power user. Then you just need to install one outlet.


Billy_Bob is offline   Reply With Quote

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Wiring in New Addition? sandyman720 Electrical 6 11-27-2011 03:34 PM
Sharing Neutrals on the same phase electro Electrical 30 08-12-2010 02:10 PM
Generator as sole power source NGuy Electrical 29 12-20-2008 12:29 AM
15 or 20 amp socket with #10? Mdbuilder Electrical 16 12-11-2008 12:27 PM
radiant floor heat thermostat kornbln Electrical 5 03-27-2008 12:45 PM

Top of Page | View New Posts


Search Engine Friendly URLs by vBSEO 3.6.1