RonPecinaJr
Senior Member
- Location
- Rahway, NJ
Why would my power company (PSEG) require the 'C' phase be used for the high-leg of a 4-wire 120/ 240 delta system (meters, main disconnects), but the NEC requires the high leg be wired to the 'B' phase?
Poco Requirements vs NEC Requirements
- Thread starter RonPecinaJr
- Start date
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wirenut1980
Senior Member
- Location
- Plainfield, IN
There is no electrical reason to choose one phase over another from the POCO's perspective. I imagine it is just their standard so as to make it easy for their service guys to remember which one is the high leg. I don't think the NEC requires B phase to be the high leg. It only says that the high leg needs to be identified and marked accordingly.
Edit to add: This particular POCO also wires their delta secondaries that way (with C phase being tghe high leg).
Edit to add: This particular POCO also wires their delta secondaries that way (with C phase being tghe high leg).
brantmacga
Señor Member
- Location
- Georgia
- Occupation
- Former Child
It requires the center buss (B) to be the high leg.
The POCO's 3-phase metering equipment requires the C phase be the high leg.
wirenut1980
Senior Member
- Location
- Plainfield, IN
It turns out we are both wrong, sort of. :grin:
There is an exception to 408.3(E) to allow matching the high leg phase to the metering equipment. I was not clear about that in my first post.
- Location
- Bremerton, Washington
A meter is not required in the NEC. Since the POCO wants the high leg on C phase, go with it, and roll them to put high leg on B phase in your gear. Their meters have a standard for high leg to have it on C phase.
Pierre C Belarge
Senior Member
- Location
- Westchester County, New York
As Tom has mentioned, one way or the other, the POCO and their trained men are looking for C leg.
The NEC requires the B leg, at least for disconnects and panels.
The one item to be sure of is the identification of the leg, whichever one you wind up using.
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
That's what we do here, too. In metering and older existing equipment, the high leg is on the right-most terminal and in new equipment, we put the high leg in the center.
- Location
- Massachusetts
hillbilly1
Senior Member
- Location
- North Georgia mountains
- Occupation
- Owner/electrical contractor
From what I've been told by POCO engineers, it is for their metering purposes that the Hi leg is on "C". Code requires it to be on "B" so that the Hi leg is always on the center buss bar, regardless of view of buss bars. (free standing gear with removable covers front and rear,)
Jim W in Tampa
Senior Member
- Location
- Tampa Florida
Why is that a violation ?
SiddMartin
Senior Member
- Location
- PA
POCO here requires high leg on C phase also. I was told they want it the furthest away from the Neu. (in the meterbase). We also then roll it to the B phase in the panel
radiopet
Senior Member
- Location
- Spotsylvania, VA
Is it not because the meter does not use the high leg for meter operation. From what I am told the meter does not work with the high leg in their setup so they move it to the "C" terminal in the meter and when it comes into the building it needs to go to "B" center terminal based on the NEC.....Could be wrong but this is what I am told and it stands to reason.
- Location
- Massachusetts
Sorry I am just not buying that.
Cow
Senior Member
- Location
- Eastern Oregon
- Occupation
- Electrician
That's what we do too. We used to run it BOY all the way through the meterbase to the panel unless we knew it was high leg. Every once in a while though, we'd have a hiccup and mistaked wye for high leg and had to move it over in the meterbase. We've changed policy since, it's now BYO through the meter to BOY in the panel everytime regardless of high leg or not. This way there are no screwups.
- Location
- Massachusetts
If your taking phase C from the power company and landing it on phase B in your panel it sounds like a problem with 408.3(E).
- Location
- Illinois
- Occupation
- retired electrician
While the utility may require the high leg to be landed in the "C" phase position at their meter, it is not "C" phase, it is "B" phase. Older meters required that the high leg be landed on the right side or "C" phase terminal to work correctly. I am told that is not true for the new electronic meters.
Jim W in Tampa
Senior Member
- Location
- Tampa Florida
Did you read the exception ?
- Location
- Massachusetts
That only applies when the meter is part of the panelboard or switchgear.
radiopet
Senior Member
- Location
- Spotsylvania, VA
In my area, the POCO makes the connections within the meter and they tell the contractor where to make the connections. The locality states it is outside the scope of the NEC and the POCO makes that choice. The AHJ made that call on many issues when dealing with the POCO...so much so that many times our hands are tied over the situation.
On a different note I should add that I started a huge deal with Virginia Power over "exclusive control" on a few jobs and was quietly told to "Shut Up" by the political machine....so I dont cause many waves in those areas unless I want to look for other employment...;(
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