I didn't say "grounded" i said "grounding" but yesYou are meaning "equipment ground", not grounded conductor? Correct?
I didn't say "grounded" i said "grounding" but yesYou are meaning "equipment ground", not grounded conductor? Correct?
don't you feel fortunate to have inherited this job ? :grin:
I didn't say "grounded" i said "grounding" but yes![]()
is the lighting system 277V?
Are they connected to the 120/208 neutral?
Does any one see where this is going?
Wye to Delta load.
If the cause is electrical in nature, and not magnetic, I don't think that is the difference. When transforming between wye and delta, one phase's current on the wye side is split between two on the delta side, and vice versa.I think the problem is utility's don't use a common core transformer like the OP is, without the common core there is no problem.
Anybody got a picture of the connections inside the transformer of a corner grounded delta. I understand what you guys are saying kind of but never seen one and in my mind it sounds like it would be a dead short (phase to ground).
If the cause is electrical in nature, and not magnetic, I don't think that is the difference. When transforming between wye and delta, one phase's current on the wye side is split between two on the delta side, and vice versa.
It's no different than bonding any supply conductor. What's throwing you off is never having OCP on a grounded conductor in most services.Anybody got a picture of the connections inside the transformer of a corner grounded delta. I understand what you guys are saying kind of but never seen one and in my mind it sounds like it would be a dead short (phase to ground).
No, when transforming wye to wye, there is no heating issue, and I believe the primary X-0 must be connected to the supply to keep the secondary voltages stable.I always thought the utility's did connect the X0 at both points when going from a Y source to a Y transformer, and because they don't use a common core transformer they could?![]()
Craig, To expound a little on what Jim notes (in case you aren't familiar with that) the Code reference is 240.85. You breakers for this installation would not be "slash rated" ie: 480/277 but would be straight rated.
Do you know what cat# breakers are being used ?
Let me throw this in. On a installation I did with 208 prim. 480 sec. for a crane I installed a fusible disconnect on the 480 side. My B phase was grounded, and I cannot recall the code #,but I installed a "no blow" fuse on B phase in the disconnect.