hi leg termination

[codeworks]

our local utility requires the high leg to hit the c phase in the meter. i can't get an electrician to land it on the b phase in the panel per 408.3. they arque up amd down, the old bo 's stand was " if thats what the power company wants, we can't fight them, they supply power. i dont see how the power company can dictate in the panel, it aint theirs. any ideas?

 

[jar546]

The meter base only gets the high leg on the right but then back to center at the disco

 

[jar546]

The meter will only work when the high leg is on the right ©

Some meter bases swap it over so from the POCO it hits the A phase of the meter base which gets moved over to the C where it leaves to the disco

Most meter bases even have a orange sticker showing where the high leg goes

 

[codeworks]

i just had a conversation with the operations guy at the local poco. their 3 phase meters wont recognize the service if the high leg isn't on c phase. local electricians are about to get reeducated. from here on out, the high leg will be on the b phase in the panel per 408.3 . the power co. could care less where it lands after the meter. i've been fed c@#p! dang it, oh well. live and learn . apparently the high leg on c phase in the panel has been the norm here for quite some time. (long before i got here, just a year ago) cause i've been trying to correct this practice for a year, now i can start. thanks all

 

[BSSTG]

The meter base only gets the high leg on the right but then back to center at the disco

That's the way it's been done down here in southeast Tx for a long time. Always verify proper identification though.

BS

 

[codeworks]

bs, you telling me that the high leg hits c phase there also ? i just relayed the above info to my bo and he wants to know why the high leg is REQUIRED to hit the b phase, in the code. i don't have that answer. any body? i just learned it, it's in the code, thats how it's done. kinda like why is the sky blue. because it is.

 

[Gregg Harris]

408.3 Support and Arrangement of Busbars and Conductors.

(A) Conductors and Busbars on a Switchboard or Panelboard.

(E) Phase Arrangement. The phase arrangement on 3-phase buses shall be A, B, C from front to back, top to bottom, or left to right, as viewed from the front of the switchboard or panelboard. The B phase shall be that phase having the higher voltage to ground on 3-phase, 4-wire, delta-connected systems. Other busbar arrangements shall be permitted for additions to existing installations and shall be marked.

Exception: Equipment within the same single section or multisection switchboard or panelboard as the meter on 3-phase, 4-wire, delta-connected systems shall be permitted to have the same phase configuration as the metering equipment.

Informational Note: See 110.15 for requirements on marking the busbar or phase conductor having the higher voltage to ground where supplied from a 4-wire, delta-connected system.

110.15 High-Leg Marking. On a 4-wire, delta-connected system where the midpoint of one phase winding is grounded, only the conductor or busbar having the higher phase voltage to ground shall be durably and permanently marked by an outer finish that is orange in color or by other

70-36

effective means. Such identification shall be placed at each point on the system where a connection is made if the grounded conductor is also present.

 

[BSSTG]

bs, you telling me that the high leg hits c phase there also ? i just relayed the above info to my bo and he wants to know why the high leg is REQUIRED to hit the b phase, in the code. i don't have that answer. any body? i just learned it, it's in the code, thats how it's done. kinda like why is the sky blue. because it is.

yessir, that would be in the meter enclousre. when it's run in the service equipment the it goes to the middle leg.

BS

 

[Gregg Harris]

bs, you telling me that the high leg hits c phase there also ? i just relayed the above info to my bo and he wants to know why the high leg is REQUIRED to hit the b phase, in the code. i don't have that answer. any body? i just learned it, it's in the code, thats how it's done. kinda like why is the sky blue. because it is.

Before 2005 NEC required the high leg to land on "C" 2005 to 2011 it is designated to land on "B" for a 3 phase 4 wire Delta connection per 408.3 and be permanently marked per 110.15, 215.8, 230.56. and 408.3 (F).

(F) Switchboard or Panel board Identification.

(1) High-Leg Identification. A switchboard or panel board containing a 4-wire, delta-connected system where the midpoint of one phase winding is grounded shall be legibly and permanently field marked as follows:

“Caution______Phase Has______Volts to Ground”

The reasoning behind it is to help prevent using a single pole breaker on the "B" leg. On a three phase 4 wire Delta connected system one phase is grounded to provide 120 volts between A and neutral and C and neutral.

A-B =240 volts

B-C =240 volts

C-A = 240 volts

A-N = 120 volts

B-N = 208 volts

C-N = 120 volts

 

[BSSTG]

Greetings

1990 NEC 384.3 (f)

Phase Arrangement. The phase arrangement on three-phase buses shall be A, B, C from front to back, top to bottom, or left to right, as viewed from the front of the switchboard or panelboard. The B phase shall be that phase having the higher voltage to ground on 3-phase, 4-wire delta-connected systems.

Like I said it's been required for awhile. I know it's the same in the '84 Code too. I don't have that one in my office though.

BS

 

[gfretwell]

384-3(f) says the same thing in 1975.

 

[codeworks]

ok. thank you all for the code sections. i'm very aware of it. i knew about it in 1984 when i first started working with codes. having a master electricians license in 3 states helps ( i'd think it would make more of a difference than it does, some just could care less about qualifications), "we've been doing it this way here for years and thats how w'ere going to do it", "sorry, we are the building dept. you shall do it this way, as thats what the code says" i do know whats right and wrong, convincing others has been the issue ( i do know what i'm looking at and talking about, i've installed a lot of 3 phase power) i've been trying ( to no avail) to correct a bad situation here, since i got here. now that the information has been handed up, poco is educated on code rules ( nec) it's up to the boss to take it from here, and fiqure out how to institute it. , thanks again

 

[BSSTG]

ok. thank you all for the code sections. i'm very aware of it. i knew about it in 1984 when i first started working with codes. having a master electricians license in 3 states helps ( i'd think it would make more of a difference than it does, some just could care less about qualifications), "we've been doing it this way here for years and thats how w'ere going to do it", "sorry, we are the building dept. you shall do it this way, as thats what the code says" i do know whats right and wrong, convincing others has been the issue ( i do know what i'm looking at and talking about, i've installed a lot of 3 phase power) i've been trying ( to no avail) to correct a bad situation here, since i got here. now that the information has been handed up, poco is educated on code rules ( nec) it's up to the boss to take it from here, and fiqure out how to institute it. , thanks again

Greetings again,

The bad thing about all of this is that we are showing our AGE!