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Joined: Jun 2007
Posts: 20
I'm working more and more on three phase 120v 208v; 277v 480v applications I need a method of computing the circuit numbers into the phase of the circuit. Accuracy and efficiency is key.
I've been told there is a way to correlate the number with a multiplier and Identify the circuit phase. Any body ever heard of such methods or other applicable means would be greatly appreciated.

Joined: Jan 2003
Posts: 4,391
A company I worked for gave us all stickers the size of a business card with a chart of circuits 1 to 84 identified by phase and the colors we use.

We stuck them inside our hard hats, they also gave us laminated versions for our wallets.

In my opinion it was worth it, you can make them yourself on a PC.

Bob Badger
Construction & Maintenance Electrician
Joined: Jul 2006
Posts: 1
Junior Member
Divide circuit number by 6. Remainder will tell you what phase. 1 or 2 A phase, 3 or 4 B phase, 5 or no remainder C phase.

Joined: Jun 2007
Posts: 20
I appreciate the tips greatly.!!!

Joined: Oct 2000
Posts: 2,722
Broom Pusher and
The method posted by OUSoonerFan3 is what you were looking for - regarding the "Mathematical Way".
If you are good with Math, this will work great for 3 Phase "L-R" Circuitry (Circuitry in Panelboards, with Circuits on the "Left" and the "Right" sides).

It doesn't work with the following configurations:
  • Single Phase "L-R" Panels,
  • Panels / Gear with only a "Single Row" of Circuitry,
  • Power Panelboards with multipole Circuitry under the same "Number" - such as a 3 pole OCPD at the upper left of a Panelboard identifies A, B and C as "Circuit 1",
  • Panelboards with "Stack Breakers" or "Piggyback Breakers" - such as a "QO-20/20",
  • Old "Bulldog" / "Pushmatic" Panels

Iwire's response brings up a very good point - create color charts for various scenarios.

I have created a set of these in Excel, which you may use if needed.
Just E-amil me, and I will bounce it your way.


Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!
Joined: Sep 2007
Posts: 1
New Member
Hello Scott i am new here and read your post on phase and circut identifiers color and # charts I would greatly like to get them charts!!! the cubs are drivin me!!! so would you please bounce em my way thank you EUGENE

Joined: Oct 2000
Posts: 2,722
Broom Pusher and

Send me an E-mail (so I can get your address), and I will pass on the spreadsheet to you.


BTW, my E-mail address may be found by either:
  1. Clicking on my user name in this reply (underlined link in the left pane),

  2. Clicking on my username in the Moderator list at the bottom of this thread.


Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!
Joined: May 2004
Posts: 73
My method works whether the breakers are numbered the normal way (of odds on the left and evens on the right)or 1 to 21 on the left and 22 to 42 on the right. It just identifies C phase though. I just see if the number is a factor of six. Even numbers who's sum is divisible by 3 is how I've been doing it if I didn't have a chart. Examples: 30 even number 3+0=3; 54 even 5+4=9; 84 even 8+4=12; 102 even 1+0+2=3. So the normal numbering system identifies C phase on the right side only you have adjust accordingly. The other numbering system (1-21 on the left) just identifies every other one. So there.

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