3 phase parallel feeders free download
Be careful though, since one of the primary concerns when installing parallel conductors is ensuring that each conductor in the paralleled set has the same electrical characteristics as the others in the same set. All of the paralleled conductors in each phase, neutral or grounded set must be the same length and be made from the same conductor material. They must be the same circular mil area and have the same type of insulation.
Finally, all parallel conductors must be terminated in the same manner. This ensures that each conductor in the parallel set will carry the same amount of current. However, one-phase, neutral or grounded circuit conductors are not required to have the same physical characteristics as those of another phase, neutral or grounded conductor. Any taps made to the paralleled sets of conductors must be made to all the conductors in the set, not just one. Tapping only one of the conductors in the set could result in an imbalance with one of the conductors carrying more current than the other, resulting in heating of that one conductor and possible insulation damage or failure.
For example, if three kcmil conductors are run per phase, a tap from that particular phase must be a tap from all of the kcmil conductors, not just one of the set. This would require a common terminal point for all three parallel conductors with a tap conductor connection to the common terminal. Where paralleled conductors are run in separate raceways or cables, the raceways or cables must have the same physical characteristics.
For example, if there are four kcmil conductors in a paralleled set of phase conductors, the four separate raceways enclosing the conductors must be all rigid steel, all IMC, or all PVC, etc. The paralleled conductors in each phase, polarity, neutral, grounded circuit conductor, equipment grounding conductor, or equipment bonding jumper shall comply with all of the following: 1 Be the same length 2 Consist of the same conductor material 3 Be the same size in circular mil area 4 Have the same insulation type 5 Be terminated in the same manner 3 Separate Cables or Raceways.
Where run in separate cables or raceways, the cables or raceways with conductors shall have the same number of conductors and shall have the same electrical characteristics. Conductors of one phase, polarity, neutral, grounded circuit conductor, or equipment grounding conductor shall not be required to have the same physical characteristics as those of another phase, polarity, neutral, grounded circuit conductor, or equipment grounding conductor.
Conductors installed in parallel shall comply with the provisions of Where parallel equipment grounding conductors are used, they shall be sized in accordance with Where parallel equipment bonding jumpers are installed in raceways, they shall be sized and installed in accordance with Last edited: Nov 5, I was looking at older code since that is what the municipality is going by and it did not have that verbage in there of 3 Separate Cables or Raceways.
What edition of the code are you using? Dennis Alwon said:. I believe he may be up your way. What code is Chicago using? Location Connecticut Occupation Engineer. Cableman said:. Thanks David, I had forgotten about that section. Location NE Nebraska. Cableman, the reason you want to follow those requirements is that each individual conductor making up a parallel conductor set needs to have the same impedance as the other individuals of the set.
If they are not the same impedance the one with the lowest impedance will end up carrying a higher amount of current, and could easily carry enough to actually overload that individual conductor. Just a. By not having same length and conductor type, you change resistance, by not placing every conductor of the set in the same circumstances like one conductor of each phase in each raceway, each raceway be of same type, etc.
Posted by: ecsanyi on Friday, April 23, at pm Tagged with: connections , delta-delta , paralelling , short circuit , three-phase , Transformers , wye-wye. Combining warm white lights with yellow lights or using it against a painted wall can exude warmth and welcome in a room.
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Rated Voltage: / ± 6%, 3 Phase, 4 Wire. Neutral: Solidly Earthed. Fault Level: 31 MVA at V. The nominal mains frequency is 50 Hz. A three-phase, Hz, untransposed transmission line runs in parallel with a telephone line for 20 km. The power line carries a. The most popular reason for paralleling conductors is to provide higher ampacity than a single conductor can provide. “In a typical building design.
