Corner Tap vs Center Tap Grounding
- Thread starter ltrain400
- Start date
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MAC702
Senior Member
- Location
- Clark County, NV
Then perhaps you can elaborate on where you got them and why you are working with them. That helps us determine how to explain it.
iceworm
Curmudgeon still using printed IEEE Color Books
- Location
- North of the 65 parallel
- Occupation
- EE (Field - as little design as possible)
Yeah - I'm with MAC.
Need some context
Nameplate data would also be good
Need some context
Nameplate data would also be good
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
It appears to be a trio of 12kv primaries connected in Y and a trio of 120/240v secondaries also connected in Y, which should be actually putting out 416/240v.
- Location
- Wisconsin
- Occupation
- PE (Retired) - Power Systems
The pictures appear to be of 3-phase transformer, or a bank of 3 1-phase units, connected grounded wye HV with a corner grounded open-delta LV.
Is there a prize for the correct answer?
Is there a prize for the correct answer?
mivey
Senior Member
The first looks like a mis-wired mess to me. The primary appears like a normal wye configuration.
The secondary would be an open delta except that both the "A" and "B" winding are present. For a closed delta the "A" winding could be present but would have A:X1 to C:X3 and A:X3 to B:X1. Or for a closed delta the "B" winding could be present but would have B:X1 to C:X3 and B:X3 to A:X1. With the "1 2 3" secondary labels, option #2 makes more sense.
You could get rid of the "B" transformer and all is well for a corner grounded open delta but still does not explain the 240/120 label.
For 240/120 high-leg (closed or open), one of the X2 terminals would be grounded.
The secondary would be an open delta except that both the "A" and "B" winding are present. For a closed delta the "A" winding could be present but would have A:X1 to C:X3 and A:X3 to B:X1. Or for a closed delta the "B" winding could be present but would have B:X1 to C:X3 and B:X3 to A:X1. With the "1 2 3" secondary labels, option #2 makes more sense.
You could get rid of the "B" transformer and all is well for a corner grounded open delta but still does not explain the 240/120 label.
For 240/120 high-leg (closed or open), one of the X2 terminals would be grounded.
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