Situation -
Two phase 277/480volt 3 wire power is fed to meter base from utility. Service disconnect installed with ground rod and GEC at site made pedestal/stand. Load side of service disconnect runs to hung 25kva single phase transformer with 480 volt primary and 3 wire center tapped 120/240volt secondary. GRC is used between the disonnect and transformer, and only the phase(ungrounded) conductors are run to the XFMR. The installation is outdoors and used to feed a distribution center wich subsequently feeds a DSL/phone cabinet on a concrete pad (about 4 feet away).
The distribution center is designed for 120/240 volt single phase power, with a main and space for 20 1 pole circuits, self contained surge protection, and power indicators. The pad has a #2 ground ring built beneath it, and is properly bonded to the distribution center and the DSL equipment.
A 3 wire feeder is run between the distribution center and the transformer (SDS). In the distribution center, a N-G bond is installed via manufactured screw.
The other end of the feeder is connected as follows...
L1 - X1 L2 - X4 X2 - X3
N - case ground (at XFMR)
The primary is connected as follows...
phase A - H1 phase B - H2
Questions
1) What would the voltage to ground be from line 1 in the distribution center?
2) What would the voltage be from line 1 to line 2 in the distribution center?
3) What would happen if a line to nuetral load were to be utilized out of the distribution center?
ps - this is just for fun - no wrong answers, I want to share a recent experience of mine with others.
Enjoy your day!
Two phase 277/480volt 3 wire power is fed to meter base from utility. Service disconnect installed with ground rod and GEC at site made pedestal/stand. Load side of service disconnect runs to hung 25kva single phase transformer with 480 volt primary and 3 wire center tapped 120/240volt secondary. GRC is used between the disonnect and transformer, and only the phase(ungrounded) conductors are run to the XFMR. The installation is outdoors and used to feed a distribution center wich subsequently feeds a DSL/phone cabinet on a concrete pad (about 4 feet away).
The distribution center is designed for 120/240 volt single phase power, with a main and space for 20 1 pole circuits, self contained surge protection, and power indicators. The pad has a #2 ground ring built beneath it, and is properly bonded to the distribution center and the DSL equipment.
A 3 wire feeder is run between the distribution center and the transformer (SDS). In the distribution center, a N-G bond is installed via manufactured screw.
The other end of the feeder is connected as follows...
L1 - X1 L2 - X4 X2 - X3
N - case ground (at XFMR)
The primary is connected as follows...
phase A - H1 phase B - H2
Questions
1) What would the voltage to ground be from line 1 in the distribution center?
2) What would the voltage be from line 1 to line 2 in the distribution center?
3) What would happen if a line to nuetral load were to be utilized out of the distribution center?
ps - this is just for fun - no wrong answers, I want to share a recent experience of mine with others.
Enjoy your day!