Corner Grounded Delta 3-phase

[hardworker]

Will corner grounded delta 3-phase converted to single phase yield 240vt or 208 as well as 120vt.

 

[mcclary's electrical]

Will corner grounded delta 3-phase converted to single phase yield 240vt or 208 as well as 120vt.

A four wire Open Delta can have 120/240 Single Phase as well as 240 Volt three phase.

 

[hardworker]

Will it yeild 208 or only 240?

 

[ptonsparky]

240v unless you got something special going on.

 

[augie47]

with a corner gorunded delta, one of your phases is grounded as opposed to a wye or "tapped" delta, so unless you have something very unusual, will will have no 120 volt source. On a 240 corner grounded delta you have 240 phase to phase, 240 phase to ground on two legs and 0 to ground on the third (grounded) phase.

 

[augie47]

If it helps, the sketch shows a center tap delta with a neutral "N".
On a corner grounded, there would be no "N" tap and "B" would be grounded instead.

 

[hardworker]

In further checking this system, I see 3 conductors coming from the street to the meter. 2 are insulated and 1 is a bare ground cable.

Does that confirm this is a corner grounded delta 3-phase?

 

[hurk27]

In further checking this system, I see 3 conductors coming from the street to the meter. 2 are insulated and 1 is a bare ground cable.

Does that confirm this is a corner grounded delta 3-phase?

It could, but the main thing to confirm a corner grounded delta is the voltage you measure as was said in other post.

I have had corner grounded deltas changed in the past to a single 3-wire service, and for the most part, depending upon how it was wired most of the service stays the same, utility will have to swap out the tanks, the panel breakers, and a few items to bring it up to code, and of course the loads, in the old days white was rarely used for the grounded conductor on a corner grounded delta as this will have to be addressed also, in many cases the panel was just a single phase 3-wire panel, larger services might have a higher AIC but still had a neutral bar and a MBJ, so panel might have to be changed, it will depend upon its rating. meter will also have to be changed out from a 5 jaw to a 4 jaw base

 

[LarryFine]

Does that confirm this is a corner grounded delta 3-phase?

Possibly. If you can get a look at the transformer secondary connections, and know what you're looking at/for, you can tell.

Or, if you measure the voltage between each pair of all three line conductors and report back here, we can tell you instantly.

 

[ptonsparky]

or call the POCO with the meter # and they should be able to tell you what you have.