Corner grounded Delta

[wyliesdiesels]

I know this type of connection has come up randomly on here over the years. So i thought i would post pics of one in my town. There are only a few left around here and theyre becoming more and more rare across the US as the grids are updated to more modern services (eg. 480Y/277)...

The large metal can is where the meter is housed. The donuts, on the cross bar up on the pole, are the CTs (note only 2; the meter is connected to each CT and ground and thus there is no potential or way to meter the third leg since its bonded to ground). Transformers are connected Wye on the high side. (forgot to take pics of those)

 

[AngryBeaver]

What kind of facility is this feeding? B phase ground is what it’s considered nation wide and still used in many refineries, chemical plants, and other highly flammable environments as there is 1/3 less potential for and arc flash on equipment failure.

 

[wyliesdiesels]

What kind of facility is this feeding? B phase ground is what it’s considered nation wide and still used in many refineries, chemical plants, and other highly flammable environments as there is 1/3 less potential for and arc flash on equipment failure.

Its feeding a warehouse that is currently occupied by habitat restore. nothing industrial...

 

[MBfreak]

Wonderful engineering. At least one phase that will have no flashover to ground!

Ola

 

[Terry D]

We still have a lot of 240 and 480 Delta here in St. Louis. I installed a new 600 amp 240 Delta service about 6 years ago. The utility really doesn't want any new systems installed, only special circumstances. One thing that we don't have here is center tapped delta. No high leg. The older buildings that have a 3 phase delta will also have a single phase 120/240.