transformer question

[steveng]

480 delta 208/120 wye 15kva 3ph primary ocpd 30 amp brkr,

L1 - L2 L2 - L3 L1-L3 secondary voltage at panel
202 203 202


L1 - n L2- n L3 -n
115 115 116


L1-g L2 -g L3-g
115 149 90


N- g
25volts




need input on the Line to gnd readings, what cases the imbalance?

also the 25 volts between n-g, is this acceptable?

this xfmr 480 3 ph feeder is #6 approx 300 feet run,

thanks for input, comments

steve

 

[tortuga]

How old is it?
How is it loaded?
Can you measure the amps?
120V loads or 3PH loads?
Are you using a true RMS meter?
Do you have something like an Ideal sure test circuit analyzer to measure impedance?

 

[iwire]

The transformer is not bonded, XO must be bonded to the EGC and a GEC must be installed.

Your N to G reading should be pretty close to 0 at the panel.

Once it is bonded you L to G readings will come around to normal.

 

[chaterpilar]

a)Is transformer neutral solidly bonded to ground?

b) If yes, then it is time to check the earth pit.

cheers.

 

[steveng]

The transformer is not bonded, XO must be bonded to the EGC and a GEC must be installed.

Your N to G reading should be pretty close to 0 at the panel.

Once it is bonded you L to G readings will come around to normal.

thanks bob, your clear concise answers are sweet!
appreciate you , sir!!