ECN Forum Forums General Topics of the Trade General Discussion Area 3 phase numbering

can someone refresh my memory on how to figure out what circuit # is on what phase.
I think it was divide the circuit # by 6 then the remainder will determine what phase it is on????

Thanks.

It always be on sum of 3 so like example if I want to know what phase it will be on Ciruit #24 24/3 = 6 so with #6 it will be end up on C phase.

#6 and #3 are on phase C depending on how you read the bussbar arrangement but normally they will be read from top to bottom.

Merci,Marc

Marc thanks for your reply,

so if you have 36 then it is "B" phase, 42 is on "A" phase and 25 is on "A" phase. Am i correct??

Thanks

Niko.,

You are close but let me expain little more clear on this one

majorty of 3Ø breaker box the bussbar arrangement is A-B-C if you look from the front the letter is left to right arrangement expect the I Line and few other the buss read 90° around it will read from front to back and also a warning here some two pole breaker and some single pole breaker may land on diffrent phase squenice espceally with some of the two pole breaker I know I deal with on the I Line series on two pole breaker it will have AB , BC or CA format it may throw you off the track when you do the set up

for the normal numbers I useally sum it by 3 unless you have oddball arrangement then go either 6 or 9 depending on the set up.

Merci,.
Marc

The rythym is Black, Black, Red, Red, Blue, Blue at 208Y120.

This is repeated seven times in the typical three phase panel of 42 circuits.

So...

1,2 Black
3,4 Red
5,6 Blue

The colors shift if we're talking 480Y277
But the rythym stays the same.

[quote=frenchelectrican] 24/3 = 6

Is that french math?

What are you guys talking about anyway?

IMHO this is the easiest way for you to do it. You are on the right path with the divide by six and then use the above chart with the remainder. I only added one change to it though.


1,2 Black **** Brown
3,4 Red **** Orange
5,0 Blue **** Yellow

You divide the circuit number in question and then use the remainder to find the circuit color.

ex.

Circuit 64

64/6 = 10 full times with a remainder of 4. Check the chart and 4 is red or orange.


Circuit 30

30/6 = 5 full times with no remainder so the 0 is used.
So it is a Blue or Yellow circuit.


Circuit 87

87/6 = 14 full times with a remainder of 3. 3 is also a red or orange circuit.



I hope I explained as close to the way I learned it. Seems easy for me, may not for others. Great part of this trade is we take from others things we can use, and sometimes it works and sometimes it doesn't.

LMK if I can explain it any better.

Philip

On dimmer racks, the busses are separated by phase, so it's easy to tell which dimmer (circuit) is on each phase. It's not as easy to find a dimmer by number, as the numbering from top goes 1, 2, 7, 8, 13, 14, etc.