[RE-wrenches] 480 Wye or Delta for a SolarEdge 10K 3-phase; how can I determine what this panel is?

[Howard "Scot" Arey]

My challenge is determining the correct 480V configuration so I can use a
3-phase Solar Edge 10000 for a 12KW commercial system.  The SE10K requires a
480V Wye configuration.

 

The main 480 panel looks straightforward.  L1, L2, L3 come from below grade
to three separate busbars in the panel.  A 4th wire, not taped white, goes
to what appears to be a ground bar at the lower right of the panel.  Green
and green-taped wires come from this bar. I do not see any physical
connections between the L1, L2, L3 bus bars and the ground bar in the lower
right, other than the box itself as the ground bar appears to be bonded to
the main box itself.

 

Voltage measurements depicts 480V at line to line, and 277 Volts from each
line to the ground (neutral?).

 

The overhead service at the road depicts 4 wires into the service head.  The
three from the three each transformers at the pole are taped traditional
3-phase colors.  The bare wire from the pole to the service head is bare
wire, but is taped white as it goes into the service head with an insulated
conductor (wire).  There is no apparent ground wire at the pole or inside
the building that I can see but the service is underground and under
concrete until it comes up inside the facility at the 480 panel board.

 

My master electrician is researching to determine the type but I wanted to
post it here for comments, too.

 

My questions:

-          Is it possible to have an ungrounded Wye where the "4th wire"
actually is a neutral to the lower right bus bar, and the wires leaving that
bar are in fact ground wires?

-          The SE10K calls for a neutral wire in a Wye config.  If this 4th
wire is a neutral, and is bonded to ground, can I run a wire from this to
the inverter neutral, then another wire from this same bar t0 other ground
wire location in the SE10K (right beside the neutral).

-          Is the white taped wire (the bare wire from the pole, then
insulated and taped white into the service head) a neutral or is that
ground.

-          Can anything other than a 480 Wye give the 480/277 voltages
indicated above?

-          If the 4th wire is a neutral (I certainly hope it is), where
might I find the ground electrode conductor (the building is relatively new,
less than 10 years I believe.).  FYI, the building is metal.

 

I look forward to your comments

 

Howard "Scot" Arey

254-300-1228

scot.arey at solarcentex.com <mailto:scot.arey at solarcentex.com> 

 



 

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