Tywais Posted December 4, 2011 Share Posted December 4, 2011 "1. Look way up on the top of the PEA distribution poles and you will see three wires carrying the three-phase power, not four wires. The neutral is not run, to save money, although there are a few exceptions. The source is a star (wye) connection."Most of the time I have seen all four wires. The fourth wire (neutral) wire usually is an uninsulated ground wire (for lightning protection). The grounded wire sometimes run along the very top of the distribution poles is for lightning protection. If it were a neutral for the system, which it is not, then the primary winding of the distribution transformers would be connected to it (L-N). Such an exposed neutral wire would be subjected to direct lightning strikes with the resultant severe electrical surges getting in your home or business. As far as I can tell it is a delta-wye connection. Looking at the pole transformer outside of my house there are the 3 high tension (22kV) lines that are the delta side and off the wye side of the transformer going to the houses are 4 wires. This is the standard method of converting to a Neutral capable 3 phase system. Link to comment Share on other sites More sharing options...
InterestedObserver Posted December 4, 2011 Share Posted December 4, 2011 "1. Look way up on the top of the PEA distribution poles and you will see three wires carrying the three-phase power, not four wires. The neutral is not run, to save money, although there are a few exceptions. The source is a star (wye) connection."Most of the time I have seen all four wires. The fourth wire (neutral) wire usually is an uninsulated ground wire (for lightning protection). The grounded wire sometimes run along the very top of the distribution poles is for lightning protection. If it were a neutral for the system, which it is not, then the primary winding of the distribution transformers would be connected to it (L-N). Such an exposed neutral wire would be subjected to direct lightning strikes with the resultant severe electrical surges getting in your home or business. As far as I can tell it is a delta-wye connection. Looking at the pole transformer outside of my house there are the 3 high tension (22kV) lines that are the delta side and off the wye side of the transformer going to the houses are 4 wires. This is the standard method of converting to a Neutral capable 3 phase system. Exactly, the H0 neutral is not carried along with H1, H2, H3 from the source substation; it is grounded at the substation through an appropriate impedance. Link to comment Share on other sites More sharing options...
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