1. Provisioning the Power System for the Porter Farms P.D. By: Marnelli Pascual Christian Brothers University 650 East Parkway S, Memphis TN 38104 MAESC CONFERENCE - 2005

2. Overview ●What is Porter Farms P.D.? ●Preliminary Designs ●Loop System ●Specifications ●Calculations ●Cost Analysis ●Project Summary

3. Porter Farms P.D. Consists of 2 Areas Consists of 2 Areas –Area 1, Subdivision with 69 lots –Area 2, Apartments with 52 units, plus 1 clubhouse Located in Collierville, TN Located in Collierville, TN

4. Project Location

5. Project Stages Stage 1 Stage 1 –Develop Area 2, Apartments Stage 2 Stage 2 –Develop Area 1, Subdivision

6. Existing Power Sources 1Ø 3Ø

7. Design 1 – Two UG Loops

8. BORE UNDER RAILROAD

9. Design 1 (cont’d) BORE UNDER THE STREET

10. Design 1 (cont’d) Advantages Advantages –Feeds are from the closest sources –No tree trimming/removal required Problems Encountered Problems Encountered –Railroad approval takes at least 90 days –Minimum railroad crossing fee of $75,000

11. Design 2 – Two UG Loops

12. LAKE NEW 1Ø OVERHEAD LINE

13. Design 2 (cont’d) Problems Encountered Problems Encountered –Crossing fee and approval from Railroad company required –City of Collierville and the homeowner’s association objected to the design –Involves tree trimming/removal

14. Design 3 One UG Loop

15. TEMPORARY OVERHEAD LINE UNDERGROUND PRIMARY

16. Design 3 (cont’d) BORE UNDER THE STREET

17. Design 3 (cont’d) Advantages Advantages –No railroad fee or approval required –No tree trimming/removal Problem Encountered Problem Encountered –Cost of $10,000 for the temporary electric

18. UG Single Loop Calculated Loads Calculated Loads –Apartments = 525kVA –Subdivision = 775kVA –Total = 1300kVA MLGW Requirement MLGW Requirement –Maximum load = 1320kVA

19. UG Electrical Loop

20. Transformer Isolation DISCONNECT

21. Specifications Fuse: (2) 100 A Fuse: (2) 100 A Transformers Used (Area 1 & 2) Transformers Used (Area 1 & 2) – (3) 50 kVA – (14) 75 kVA – (1) 100 kVA Cables & Conduits Cables & Conduits –Primary: #2 insulated copper inside 2” pvc conduit –Secondary: 350 kCM triplex inside 3” pvc conduit Meter Sockets (Apartments) Meter Sockets (Apartments) –(12) 6-Gang Meter – (2) 2-Gang Meter – (1) Single Meter

22. Specifications (cont’d) 6-Gang Meter Socket 6-Gang Meter Socket RISER ENTRY

23. Specifications (cont’d) Location of Facilities Location of Facilities – Riser Location

24. Specifications (cont’d) Location of Facilities Location of Facilities – Transformer Location (Apartments)

25. Specifications (cont’d) Location of Facilities Location of Facilities – Transformer Location (Subdivision)

26. Calculations Cost: Software-calculated Cost: Software-calculated Fuse: No calculation needed Fuse: No calculation needed Cables & Conduits Cables & Conduits –Size: Software-calculated based on cable length and load –Length: Measured from map

27. Calculations (cont’d) Cable Tension, ≤ 850 lbs. Cable Tension, ≤ 850 lbs. – Maximum Tension = 831 lbs. – Software-calculated

28. Calculations (cont’d) Transformer Size (Apartments) Transformer Size (Apartments) Load from Electrician, kWDemand FactorProjected Load, kW Lighting4.000.52.00 Receptacle4.000.41.60 Range7.000.64.20 Dryer6.000.63.60 Air Conditioning3.500.83.92 Total Load per Unit 15.32 Total Load per Unit=  (Load from Electrician)(Demand Factor) Equation 1

29. Calculations (cont’d) Transformer Size (Apartments) Transformer Size (Apartments) Transformer Load=(Total Load per Unit)(No. of Unit)(Demand Factor) Equation 2 No. of BuildingsNo. of Units Demand Factor Transformer Load Transformer Size to Use 280.785.792100 kVA 140.849.02450 kVA Calculated Total Load per Unit = 15.32 kVA

30. Calculations (cont’d) Transformer Size (Subdivision) Transformer Size (Subdivision) Number of LotsLoad Based on Sq. Ft., kVATransformer Size 436.72 50 kVA 544.56 652.36 75 kVA 761.58 865.69 968.62 1070.38 House Square Footage: 2500 sq. ft.

31. Project Cost SubdivisionApartments Total Cost$109,881.08$65,701.85 Cost per Lot/Unit $1,592.48$1,239.66 2003 Average Cost per Lot/Unit $1,594.00$679.00

32. Apartments Cost TransformerSecondary Cable Primary Cable QuantityCost, $Length, ft.Cost, $ Project 1125862001710C Project 22517080844C

33. Apartments Cost (cont’d) TransformerSecondary Cable Primary Cable QuantityCost, $Length, ft.Cost, $ Project 1125862001710C Project 22517080844C

34. Project Summary –All requirements were met –MLGW and the customer approved the final design –Project is currently under construction

35. Questions