2.0 electrical depth - pennsylvania state university

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Diane Emert Senior Thesis 2005 Broadway Plaza, Rochester, MN

2.0 Electrical Depth 2.0.1 Introduction

In addition to the Lighting Depth, the Electrical Depth focuses on studying the electrical systems that operate Broadway Plaza. Although Broadway Plaza currently has no overwhelming electrical design issues, an analysis of an alternative power distribution system for cost and efficiency is considered. As the building is currently operated, two transformers at 480V and 208V provide power distribution. Through this system, power at 480V is supplied through several primary and secondary panelboards and bus duct risers to the mechanical equipment and the loads on the multifunction floors. Two residential bus duct risers fed from the 208V transformer and related switchboards supply power to the residential floors. However, this is not the only configuration that may be utilized within a building such as Broadway Plaza. One 208V transformer may be employed, and the equipment may be specified to run from this one utilization voltage. Money may be saved through the necessity of only one transformer. However, at the same time, wire sizing will also need to be increased due to the additional amperes required. Through the consultation of a professional engineer, Mr. Edward Wunderley of Burt Hill Kosar Rittelmann Associates, and the use of the 2002 National Electric Code, analysis of this alternative system is conducted. All electrical system distribution equipment, protective devices, and feeders affected by the system change are resized based on the configuration of the 208V system. Likewise, the new lighting design affected the sizing of equipment and wiring used to run the system. New loads are calculated for the redesigned lighting system. Distribution equipment, protective devices, and feeders are then sized accordingly to meet the new lighting loads. After redesign of the entire electrical system is complete, the cost saved through the use of only one transformer is compared to the cost necessary to run such a system. This comparison is made in conjunction with the 4.0 Construction Management Breadth. The best alternative for cost savings as well as overall functionality is selected, in this case, the existing dual 480V and 208V system. 2.0.2 Electrical System Configuration/ Riser Diagrams and Single Line Diagrams To begin analysis, mechanical equipment within the system is resized as per the 120/208V system. As per the changes, new wire sizes and protective devices are selected. The panelboards affected by these changes, including all of the existing 277/480V, are resized with new feeder sizes determined. The single line diagram and riser diagram on the following pages illustrate how the new distribution system will be configured. For much of the system, the configuration of the panels is kept constant. However, due to the changes made, several important changes are also necessary.

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Distribution Configuration Although the load within the building did not change, the increase in amperes drawn and larger panel sizes requires a reconfiguration of the primary power distribution to avoid extremely large and expensive equipment. Within the existing power distribution arrangement, the 208V switchboards serving residential loads are serviced by the 208V transformer. The 480V transformer, meanwhile, serves the fire control devices, a retail switchboard, and a main distribution panel. The new configuration holds that all components will be fed from one 208V transformer. This transformer services the fire control system, residential switchboards, retail switchboard, main distribution panel, secondary distribution panel, and an additional switchboard to service the bus duct riser to the penthouse normal power distribution panel. Exact configuration can be seen within the single line diagram. Bus Duct For cost effective measures and system efficiency, the feeder serving the penthouse normal/emergency power, MDP-PHE, is changed to a plug-in bus duct riser similar to the bus duct risers already serving other parts of the high rise. Over the long distance to the penthouse, a bus duct riser holds the advantage of lower cost, faster installation, reliability, and higher efficiency (lower voltage drop). Transformers Without the use of a 480V system, the dry-type transformers used for stepping down voltage are no longer necessary. However, it is decided that two dry-type transformers will be used to step-up voltage to serve the building’s chillers. Chillers are commonly serviced by 480V. Locating the transformers within the main electrical room on the first floor and running smaller wire from this location to service the chillers on the 28th floor can minimize wire sizing. Distribution Equipment Location An issue with the new system configuration can develop when locating the electrical distribution equipment. Distribution equipment is relocated within the main electrical room and ATS room as follows.

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Figure 2.0.2a Distribution Equipment Location: Main Electrical Room, First Floor

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To summarize the electrical distribution configuration, the following charts have been composed.

Tag Description Feeder Size HP or kW Current (A) kVA Breaker

Size (A)CH-1 Chiller (2) 3"C each with (3) 500 kCmil & (1) #1/0G 164kW 569.02 205.00 800CH-2 Chiller (2) 3"C each with (3) 500 kCmil & (1) #1/0G 164kW 569.02 205.00 800AEDP Panel (4) 3"C each with (4) 350 kCmil & (1) #3/0G 759.50 273.62 1200EDP Emergency Panel (6) 3 1/2"C each with (4) 500 kCmil & (1) 250 kCmil G 1244.58 448.38 2000

3142.13 1132.01

Description Feeder Size Current (A) kVA BPS (A)

Feeder to MDP (11) 4" C each with (4) 500 kCmil & (1) 500kCmil G 3142.13 1132.01 4000


Size (A)Bus Duct to MDP-PHN 1138.138 410.033 2000


Feeder to 208V SB (6) 3 1/2" C EACH WITH (4) 500kcmil & (1) 250 kcmil G 1138.14 410.03 2000

Tag Description Feeder Size Current (A) kVA Breaker

Size (A)01HNA Panel (2) 3"C each with (4) 350 kCmil & (1) #1G 378.55 136.38 600

01HNB Panel (4) #4/0 & (1) #4G - 2 1/2" C 94.51 34.05 22502HNA Panel (4) 500 kCmil & (1) #3G - 3 1/2" C 180.39 64.99 40002LNB Panel (4) #4/0 & (1) #4G - 2 1/2" C 55.51 20.00 22503HNA Panel (2) 3 1/2"C each with (4) 500 kCmil & (1) #1/0G 435.16 156.77 80006HNA Panel (4) #4/0 & (1) #4G - 2 1/2" C 72.45 26.10 22516HNA Panel (4) #4/0 & (1) #4G - 2 1/2" C 94.65 34.10 225

Total 1311.24 472.40


Feeder to SDP-1: (5) 3 1/2" C each with (4) 500kcmil COPPER & (1) #4/0 G 1311.24 472.40 1600


Size (A)Bus Duct to MDP-PHE 903.18 325.38 1600

01HEA Panel (4) 500 kCmil & (1) #3G - 3 1/2" C 145.39 52.38 40008HEA Panel (4) #4/0 & (1) #4G - 2 1/2" C 64.88 23.37 22518HEA Panel (4) #1 & (1) #8G - 1 1/2" C 56.89 20.50 100ELEV 5 Passenger Elev. #5 (3) #1 & (1) #8G - 1 1/2" C 20 HP 59.40 26.75 100

1244.58 448.38

Description Feeder Size Current (A) kVA Breaker

Size (A)Feeder to EDP: (6) 3 1/2"C each with (4) 500 kCmil & (1) 250 kCmil G 1244.58 448.38 2000

Main Distribution Panel (MDP)- 4000A 208V Switchboard

Total

Total

Secondary Distribution Panel (SDP-1)- 1600A 208V Distribution Panel

Emergency Distribution Panel (EDP)- 2000A 208V Distribution Panel

208V Switchboard 2000A

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Size (A)CT-1 Cooling Tower Fans (3) #1 & (1) #6G - 1 1/2" C 30 HP 88.00 39.63 125

HWP-1 Hot Water Pump (3) #1 & (1) #6G - 1 1/2" C 30 HP 88.00 39.63 125HWP-2 Hot Water Pump (3) #1 & (1) #6G - 1 1/2" C 30 HP 88.00 39.63 125

CHWP-1 Chilled Water Pump (3) #1/0 & (1) #6G - 1 1/2" C 40 HP 114.00 51.34 150CHWP-2 Chilled Water Pump (3) #1/0 & (1) #6G - 1 1/2" C 40 HP 114.00 51.34 150CWP-1 Condensate Water Pump (3) #1/0 & (1) #6G - 1 1/2" C 40 HP 114.00 51.34 150CWP-2 Condensate Water Pump (3) #1/0 & (1) #6G - 1 1/2" C 40 HP 114.00 51.34 15027HNA Panel (4) #4/0 & (1) #4G - 2 1/2" C 238.14 85.79 400

1138.14 410.03


Size (A)ELEV 1 Passenger Elev. #1 (3) #1 & (1) #6G - 1 1/2" C 30 HP 88.00 39.63 125

ELEV 2 Passenger Elev. #2 (3) #1 & (1) #6G - 1 1/2" C 30 HP 88.00 39.63 125

ELEV 3 Passenger Elev. #3 (3) #1 & (1) #6G - 1 1/2" C 30 HP 88.00 39.63 125ELEV 4 Freight Elev. #4 (3) #1/0 & (1) #6G - 1 1/2" C 40 HP 114.00 51.34 15027HEA Panel (4) 500 kCmil & (1) #3G - 3 1/2" C 174.93 63.02 400SP-1 Stair Pressurization (3) #8 & (1) #10G - 3/4" C 10 HP 30.80 13.87 40SP-2 Stair Pressurization (3) #8 & (1) #10G - 3/4" C 10 HP 30.80 13.87 40

MUA-1 Make-up Air Handler (3) #3/0 & (1) #6G - 2" C 50 HP 143.00 64.40 200903.18 325.38


Size (A)Bus Duct to Retail 1249.075 450 1600


Feeder to 208V SB (5) 3 1/2" C each with (4) 500kcmil COPPER & (1) #4/0 G 1249.08 450.00 1600

Retail 208V Switchboard 1600A

Total

Total

Emergency Distribution Panel Mechanical Penthouse (MDP-PHE)- 1600A 208/120V Switchboard

Main Distribution Panel Mechanical Penthouse (MDP-PHN)- 2000A 208/120V Switchboard

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2.0.3 Cost Analysis In conjunction with the 4.0 Construction Management Breadth, the first cost of each system is compared. If resizing does not affect the equipment size from the existing design, the equipment is neglected from comparison due to the similar pricing available. This is particularly relative to the mechanical equipment analyzed. RS Means Electrical Cost Data 2003 is used for all portions of this analysis for consistency purposes. Therefore, time and location factors are also considered. For more information on the pricing of this information, please review the 4.0 Construction Management Breadth. The following summaries are cost comparisons for equipment that has been resized.

Tag Description Breaker Size (A)

Cost (Each)

Breaker Size (A)

Cost (Each)

BS-1 Domestic Booster Pumps 500 509.50 250 796.00CH-1 Chiller 800 728.50 350 955.00CH-2 Chiller 800 728.50 350 955.00

CHWP-1 Chilled Water Pump 150 254.00 70 510.00CHWP-2 Chilled Water Pump 150 254.00 70 510.00

CP-1 Condensate Pump 20 45.00 20 125.00CT-1 Cooling Tower Fans 125 235.75 60 456.50

Cooling Tower Sump Heater 100 217.50 40 265.00CWP-1 Condensate Water Pump 150 254.00 70 510.00CWP-2 Condensate Water Pump 150 254.00 70 510.00EBB-1 Electric Baseboard Heater 50 94.00 20 125.00EBB-2 Electric Baseboard Heater 40 75.00 20 125.00EBB-3 Electric Baseboard Heater 30 53.80 20 125.00EDH-1 Electric Duct Heater 100 217.50 50 335.00EF-1 Garage Ventilation Fan 30 53.80 20 125.00

ELEV. 1 Passenger Elevator 125 235.75 60 456.50ELEV. 2 Passenger Elevator 125 235.75 60 456.50ELEV. 3 Passenger Elevator 125 235.75 60 456.50ELEV. 4 Freight Elevator 150 254.00 70 510.00ELEV. 5 Passenger Elevator 100 217.50 40 265.00EUH-1 Generator Rm. Unit Heater 125 235.75 60 456.50FP-1 Fire Pump 800 728.5 350 955JP-1 Jockey Pump 30 53.80 20 125.00FV-2 Boiler Vent Fan 30 53.80 20 125.00

HWP-1 Hot Water Pump 125 235.75 60 456.50HWP-2 Hot Water Pump 125 235.75 60 456.50KEF-1 Kitchen Exhaust Fan 20 45.00 20 125.00MUA-1 Make-up Air Handler 200 290.50 100 687.30PDU-1 Pool Dehumidification Unit 30 53.80 20 125.00SE-1 Sewage Ejector 30 53.80 20 125.00

SEF-1 Smoke Exhaust Fan 40 75.00 20 125.00SP-1 Stair Pressurization Fan 40 75.00 20 125.00SP-2 Stair Pressurization Fan 40 75.00 20 125.00SS-1 Sump Pump System 30 53.80 20 125.00

Totals: $6,690.35 $11,753.80

208V Utility Voltage 480V & 208V Utility

Tag Description Length of Circuit (ft) Wire Size Cost (/CLF) Conduit

Size (in) Cost (/LF) Ground Size

Cost (/CLF) Wire Size Cost

(/CLF)Conduit Size (in) Cost (/LF) Ground

SizeCost

(/CLF)BS-1 Domestic Booster Pumps 70 (2)#250 1872 (2) 2.5 14.1 (2) #2 135.5 #250 1872 3 18.15 #4 102.00

CHWP-1 Chilled Water Pump 63.75 1/0 1056 2 8.71 #6 76.5 #4 536 1 1/4 6.15 #8 57.10CHWP-2 Chilled Water Pump 68.75 1/0 1056 2 8.71 #6 76.5 #4 536 1 1/4 6.15 #8 57.10

CT-1 Cooling Tower Fans 117.5 #1 908.00 1 1/2 7.28 #6 76.5 #6 525 1 4.70 #10 42.95Cooling Tower Sump Heater 117.5 #1 908.00 1 1/2 7.28 #8 57.1 #8 519 3/4 3.57 #10 42.95

CWP-1 Condensate Water Pump 106.25 1/0 1056 2 8.71 #6 76.5 #4 536 1 1/4 6.15 #8 57.10CWP-2 Condensate Water Pump 101.25 1/0 1056 2 8.71 #6 76.5 #4 536 1 1/4 6.15 #8 57.10EBB-1 Electric Baseboard Heater 135 #6 525 3/4 3.57 #10 42.95 #12 258 3/4 3.57 #12 36.40EBB-2 Electric Baseboard Heater 250 #8 519 3/4 3.57 #10 42.95 #12 258 3/4 3.57 #12 36.40EBB-3 Electric Baseboard Heater 285 #10 353 3/4 3.57 #10 42.95 #12 258 3/4 3.57 #12 36.40EDH-1 Electric Duct Heater 50 #1 908 1 1/2 7.28 #8 57.1 #6 525 3/4 3.57 #10 42.95EF-1 Garage Ventilation Fan 65 #10 353 3/4 3.57 #10 42.95 #12 258 3/4 3.57 #12 36.40

ELEV. 1 Passenger Elevator 58.75 #1 908 1 1/2 7.28 #6 76.5 #4 536 1 4.70 #10 42.95ELEV. 2 Passenger Elevator 58.75 #1 908 1 1/2 7.28 #6 76.5 #4 536 1 4.70 #10 42.95ELEV. 3 Passenger Elevator 53.75 #1 908 1 1/2 7.28 #6 76.5 #4 536 1 4.70 #10 42.95ELEV. 4 Freight Elevator 67.5 1/0 1056 2 8.71 #6 76.5 #4 536 1 1/4 6.15 #8 57.10ELEV. 5 Passenger Elevator 115 #1 908 1 1/2 7.28 #8 57.1 #8 519 3/4 3.57 #10 42.95EUH-1 Generator Rm. Unit Heater 45 #1 908 1 1/2 7.28 #6 76.5 #4 536 1 4.70 #10 42.95FP-1 Fire Pump 128 (2)#500 3100 (2) 3 18.15 (2) 1/0 193 #500 3100 3 18.15 #3 118.00JP-1 Jockey Pump 120 #10 353.00 3/4 3.57 #10 42.95 #12 258 3/4 3.57 #12 36.40FV-2 Boiler Vent Fan 142.5 #10 353.00 3/4 3.57 #10 42.95 #12 258 3/4 3.57 #12 36.40

HWP-1 Hot Water Pump 123.75 #1 908.00 1 1/2 7.28 #6 76.5 #4 536 1 4.70 #10 42.95HWP-2 Hot Water Pump 118.75 #1 908.00 1 1/2 7.28 #6 76.5 #4 536 1 4.70 #10 42.95KEF-2 Kitchen Exhaust Fan 97.5 #10 353 3/4 3.57 #10 42.95 #12 258 3/4 3.57 #12 36.40MUA-1 Make-up Air Handler 77.5 3/0 1454 2 8.71 #6 76.5 #2 692 1 1/4 6.15 #8 57.10PDU-1 Pool Dehumidification Unit 45 #10 353 3/4 3.57 #10 42.95 #12 258 3/4 3.57 #12 36.40SE-1 Sewage Ejector 155 #10 353 3/4 3.57 #10 42.95 #12 258 3/4 3.57 #12 36.40

SEF-1 Smoke Exhaust Fan 97.5 #8 519 3/4 3.57 #10 42.95 #12 258 3/4 3.57 #12 36.40SP-1 Stair Pressurization Fan 95 #8 519 3/4 3.57 #10 42.95 #12 258 3/4 3.57 #12 36.40SP-2 Stair Pressurization Fan 137.5 #8 519 3/4 3.57 #10 42.95 #12 258 3/4 3.57 #12 36.40SS-1 Sump Pump System 60 #10 353 3/4 3.57 #10 42.95 #12 258 3/4 3.57 #12 36.40

Totals: $27,927.35 $21,111.90 $2,080.65 $16,891.15 $16,308.80 $1,481.55

208V Utility Voltage Only 480V & 208V Utility Voltages Available

Panel Length of Circuit (ft) Wire Size Cost (/CLF) Original Wire

Size Cost (/CLF) Panel Length of Circuit (ft)

Conduit Size (in) Cost (/LF)

Original Conduit Size (in)

Cost (/LF) Panel Length of Circuit (ft)

Ground Size Cost (/CLF) Original

Ground Size Cost (/CLF)

01LNA 7.5 2/0 1429.00 1/0 1267 01LNA 7.5 2 8.71 2 8.71 01LNA 7.5 #6 53.00 #6 53.0002LNA 10 #4 667.00 #4 667 02LNA 10 1 1/4 6.15 1 1/4 6.15 02LNA 10 #10 34.10 #10 34.1003LNA 10 4/0 2147.00 1/0 1267 03LNA 10 2 1/2 14.10 2 8.71 03LNA 10 #4 73.50 #6 53.0003LNC 15 2/0 1429.00 #1 1126 03LNC 15 2 8.71 1 1/2 7.28 03LNC 15 #6 53.00 #8 41.4506LNA 7.5 #1 1126.00 #4 667 06LNA 7.5 1 1/2 7.28 1 1/4 6.15 06LNA 7.5 #8 41.45 #10 34.1016LNA 7.5 #1 1126.00 #4 667 16LNA 7.5 1 1/2 7.28 1 1/4 6.15 16LNA 7.5 #6 53.00 #10 34.1027LNA 12.5 #4 667.00 #10 462 27LNA 12.5 1 1/4 6.15 3/4 3.57 27LNA 12.5 #8 41.45 #10 34.1027LNB 20 #6 531.00 #10 462 27LNB 20 3/4 3.57 3/4 3.57 27LNB 20 #10 34.10 #10 34.1001LEB 10 #10 462.00 #10 462 01LEB 10 3/4 3.57 3/4 3.57 01LEB 10 #10 34.10 #10 34.1001LEA 7.5 #1 1126.00 #4 667 01LEA 7.5 1 1/2 7.28 1 1/4 6.15 01LEA 7.5 #8 41.45 #10 34.1008LEA 7.5 #6 531.00 #10 462 08LEA 7.5 3/4 3.57 3/4 3.57 08LEA 7.5 #10 34.10 #10 34.1018LEA 7.5 #6 531.00 #10 462 18LEA 7.5 3/4 3.57 3/4 3.57 18LEA 7.5 #10 34.10 #10 34.1027LEA 7.5 1/0 1267.00 #2 813 27LEA 7.5 2 8.71 1 1/2 7.28 27LEA 7.5 #6 53.00 #8 41.45Totals: $1,266.73 $934.03 Totals: $865.13 $721.38 Totals: $57.38 $49.29

Panel Length of Circuit (ft) Wire Size Cost (/CLF) Original Wire

Size Cost (/CLF) Panel Length of Circuit (ft)

Conduit Size (in) Cost (/LF)

Original Conduit Size (in)

Cost (/LF) Panel Length of Circuit (ft)

Ground Size Cost (/CLF) Original

Ground Size Cost (/CLF)

01HNA 16.5 (2) #350 2975 4/0 2147 01HNA 16.5 (2) 3" 18.15 2.5 14.10 01HNA 16.5 (2) #1 129.00 #4 73.5001HNB 18.7 4/0 2147 4/0 2147 01HNB 18.7 2 1/2 14.10 2 1/2 14.10 01HNB 18.7 #4 73.50 #4 73.5002HNA 55 #500 2985 4/0 2147 02HNA 55 3 1/2 22.35 2 1/2 14.10 02HNA 55 #3 93.50 #4 73.5003HNA 62.92 (2)#500 3985 4/0 2147 03HNA 62.92 (2) 3.5" 22.35 2 1/2 14.10 03HNA 62.92 (2) 1/0 166.50 #4 73.5006HNA 96.8 4/0 2147 #1 1126 06HNA 96.8 2 1/2 14.10 1 1/2 7.28 06HNA 96.8 #4 73.50 #8 41.4516HNA 209.5 4/0 2147 #1 1126 16HNA 209.5 2 1/2 14.10 1 1/2 7.28 16HNA 209.5 #4 73.50 #8 41.4527HNA 22 #500 3985 4/0 2147 27HNA 22 3 1/2 22.35 2 1/2 14.10 27HNA 22 #3 93.50 #4 73.50AEDP 44 (4)#350 2975 (2) #350 2975 AEDP 44 (4) 3" 18.15 (2) 3" 18.15 AEDP 44 (4) 3/0 234.00 (2) #1 129.0001HEA 12.1 #500 3985 4/0 2147 01HEA 12.1 3 1/2 22.35 2 1/2 14.10 01HEA 12.1 #3 93.50 #4 73.5008HEA 137.5 4/0 2147 #1 1126 08HEA 137.5 2 1/2 14.10 1 1/2 7.28 08HEA 137.5 #4 73.50 #8 41.4518HEA 230.5 #1 1126 #1 1126 18HEA 230.5 1 1/2 7.28 1 1/2 7.28 18HEA 230.5 #8 41.45 #8 41.4527HEA 13.2 #500 3985 4/0 2147 27HEA 13.2 3 1/2 22.35 2 1/2 14.10 27HEA 13.2 #3 93.50 #4 73.5027HEB 293 #500 3985 #1 1126 27HEB 293 3 1/2 22.35 1 1/2 7.28 27HEB 293 #3 93.50 #8 41.4527LEB 6.6 #1 1126 #4 667 27LEB 6.6 1 1/2 7.28 1 1/4 6.15 27LEB 6.6 #8 41.45 #10 34.10Totals: $32,109.56 $17,856.84 Totals: $19,586.63 $10,707.06 Totals: $1,036.83 $607.27

Ground Resizing w/o Need for Dry-Type Transformer

Ground Resizing for Resized 208V Panel Boards

Wire Resizing w/o Need for Dry-Type Transformer

Wire Resizing for Resized 208V Panel Boards

Conduit Resizing w/o Need for Dry-Type Transformer

Conduit Resizing for Resized 208V Panel Boards

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PanelBranch Circuit Breaker (A)

Cost (Each)

Original Branch Circuit Breaker (A)

Cost (Each)

01LNA 175 272.25 150 976.0002LNA 60 144.50 60 456.5003LNA 225 381.75 150 976.0003LNC 175 272.25 100 687.3006LNA 100 217.50 60 456.5016LNA 125 235.75 60 456.5027LNA 70 164.50 30 170.0027LNB 50 94.00 30 170.0001LEB 30 53.80 30 170.0001LEA 100 217.50 60 456.5008LEA 50 94.00 30 170.0018LEA 50 94.00 30 170.0027LEA 150 254.00 90 629.60Totals: $2,495.80 $5,944.90

Panel Panel Size (A) Cost (Each) Original Panel Size (A) Cost (Each)

01HNA 600 5200 225 437501HNB 225 2950 225 437502HNA 400 3750 225 437503HNA 800 6650 225 437506HNA 225 2950 100 252516HNA 225 2950 100 252527HNA 400 3750 225 4375AEDP 1200 9550 600 700001HEA 400 3750 225 437508HEA 225 2950 100 252518HEA 100 1545 100 252527HEA 400 3750 225 437527HEB 400 3750 100 252527LEB 100 1545 60 1935Totals: $55,040.00 $52,185.00

PanelBranch Circuit Breaker (A)

Cost (Each)

Original Branch Circuit Breaker (A)

Cost (Each)

01HNA 600 1059 225 64201HNB 225 642 225 64203HNA 800 1340 225 64227HNA 400 835 225 64201HEA 400 835 225 64227HEA 400 835 225 642Totals: $5,547.30 $3,852.00

Circuit Breaker Resizing w/o Need for Dry-Type Transformer

480V to 208V Panel Board Resizing

Circuit Breaker Resizing for Resized 208V Panel Boards (MLO)

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Panel Panel Size (A) Cost (Each) Original Panel Size (A) Cost (Each)

MDP-PHN 2000 4650 1000 2640MDP-PHE 1600 4065 800 2565EDP 2000 4650 1000 2640SDP-1 1600 15650 1200 3530Retail SB 1600 15650 800 12515MDP 4000 24237.5 3000 22475208V Switchboard 2000 16675 NA NATotals: $85,577.50 $46,365.00

Primary and Emergency Distribution Panel Resizing (BPS included when applicable, MCB sized without breaker)

Panel Length of Circuit (ft) Wire Size

Cost (Wire, Conduit, Ground)

Original Wire Size

Cost (Wire, Conduit, Ground)

MDP-PHE

350 NA (Bus Duct Replacement) NA

(2) 3 1/2"C each with (4) 500 kCmil & (1) 1/0 G

W-$3985/CLF

C-$39.30/LF G-

EDP

50(6) 3 1/2"C each with (4) 500 kCmil & (1) 250 kCmil G

W-$3985/CLF C-$39.30/LF G-

$327/CLF


W-$3985/CLF

C-$39.30/LF G-

$198.5/CLF

SDP-1

40


W-$3985/CLF C-$39.30/LF G-

$283/CLF

(4) 3"C each with (4) 350 kCmil & (1) 3/0 G

W-$2975/CLF

C-$33.05/LF G-$234/CLF

Retail SB

40


W-$3985/CLF C-$39.30/LF G-

$283/CLF


W-$3985/CLF

C-$39.30/LF G-

MDP

40

(11) 4" C each with (4) 500 kCmil & (1) 500kCmil G

W-$3985/CLF C-$44.30/LF G-

$572/CLF

(8) 4"C each with (4) 500 kCmil & (1) 500 kCmil G

W-$3985/CLF

C-$44.30/LF G-$572/CLF

208V Switchboard

40(6) 3 1/2"C each with (4) 500 kCmil & (1) 250 kCmil G

W-$3985/CLF C-$39.30/LF G-

$327/CLF NA NA

Totals: $84,394.50 $85,790.06

Feeder Resizing for Primary and Emergency Distribution Panels

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PanelBranch Circuit Breaker

Cost (Each)

Original Branch Circuit Breaker or BPS (A)

Cost (Each)

MDP-PHN 2000 8100 1000 4050MDP-PHE 1600 6770 800 3351EDP 2000 8100 1000 4050SDP-1 NA NA 1200 5410Totals: $22,970.00 $16,861.00

Circuit Breaker Resizing for Distribution Panels (MCB Only)

Destination Size (A) Cost (Each) Size (A) Cost (Each)To Em. Power 2000 21973 1000 15660To AEDP 1200 17214 600 10200Totals: $39,186.00 $25,860.00

Destination Size (A) Cost (Each) Size (A) Cost (Each)To Em. Power 2000 15625 1000 12115To AEDP 1200 12915 600 10515Totals: $28,540.00 $22,630.00

Bus Duct Length of Circuit (ft) Size (A) Cost (/LF) Original Size

(A) Cost (/LF)

To MDP-PHN 320 2000 284.5 1000 157.5To MDP-PHE 320 1600 240 NA NATo Retail 60 1600 240 800 146.5Totals: $182,240.00 $59,190.00

Circuit Breakers With Ground Fault Indication

Bus Ducts

Automatic Transfer Switches

Transformer (kVA) Number Used (208V) Cost Number

Used(480V) Cost (Each)

15 0 NA 4 179530 2 2125 6 212545 0 NA 2 251575 0 NA 3 3480

Totals: $4,250.00 $35,400.00

Dry-Type Transformer Pricing

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The cost of operating the system under only the 120/208V voltage is 37% more than operating the system utilizing 227/480V and 120/208V. Therefore, it is recommended that the existing design is the most acceptable for this application. 2.0.4 Calculation Methods Panelboard and Feeder Design Example Throughout the Electrical Depth, panelboards, equipment, protective devices, and all associated feeders, etc. have been resized and analyzed to operate under a 208V utilization voltage only. The following describes in detail one specific example on how Panel 27HEA is redesigned. The following motors are located on 27HEA.

Toilet Exhaust Fan TEF-1 3HP, 3ph Kitchen Exhaust Fan KEF-1 3HP, 3ph Kitchen Exhaust Fan KEF-1 5HP, 3ph

In order to design the equipment to support these motors under a 208V system, the amount of current drawn by each must be known. The following sizes TEF-1. NEC 2002: Table 430.150 Full-Load Current, Three-Phase Alternating-Current Motors

3HP at 208V = 10.6 A Multiplier of 1.25 to calculate amperes for wire sizing: 1.25 * 10.6A = 13.25A

NEC 2002: Table 310.16 THWN Copper at 75° for 13.25A = #12 AWG Standard circuit breaker = 20A Although #14 AWG wire and a 15A breaker may be used, the #12 AWG wire and 20A breaker are chosen, as they are the lowest standard sizes that are most often used in building construction.

Transformer Size (kVA) Amperes Cost Totals

208V Only 3750 10409 $61,490.00 $61,490.00480V 2500 3007 $43,035.00208V 1000 2776 $25,785.00 $68,820.00

Utility Transformer Resizing

Utilization Voltages Transformer Cost Panel/Wiring

Costs, etc.Location Factor

Time Adjustment Total Cost

208V Only $61,490.00 $622,973.60 1.02 0.975 $680,699.05480V & 208V $68,820.00 $431,389.11 1.02 0.975 $497,457.96

Total Cost Comparisons

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Summarization:

Tag Description HP or kW Phase Voltage FLA (A) Corrected Amps Wire Size Switch

Size (A)TEF-1 Toilet Exhaust Fan 3 3 208 10.60 13.25 #12 20

Lighting loads for each branch circuit to the lighting on floors 27,28,29 are found by summation of the wattage of the lamps and ballasts on each circuit. This wattage is assumed equal to the VA on the circuit. For sizing of wires and protective devices, a 1.25 multiplier must be applied, as lighting is a continuous load. 1080VA * 1.25 = 1350 VA I = 1350VA/120V = 11.25A No sqrt(3) considered as lighting is a single phase load. NEC 2002: Table 310.16 THWN Copper at 75° for 11.25A = #12 AWG Standard circuit breaker = 20A The resizing of the branch circuit breaker for the lighting panel 01LEA takes into consideration resizing of 01LEA due to the system change as well. The example is as follows. Load on 27LEA: 31640 VA Multiplier of 1.25 for future growth: 1.25 * 31640 = 39550 VA (or 13184VA per phase) FLA = 39550VA/ (SQRT(3)*208V) = 109.78A Multiplier of 1.25 to calculate amperes for wire sizing: 1.25 * 109.78A = 137.22A Panelboard 01LEA remains a 150A MCB panel NEC 2002: Table 310.16 THWN Copper at 75° for 137.22A = #1/0 AWG Summarization:

Panel Load (VA)

Future Growth (125%) (VA)

FLA (A) Corrected Amps Wire Size Breaker Size

(A)

27LEA 31640 39550 109.78 137.22 1/0 150

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Summarization of Panel 27HEA

FED FROM: MDP-PHEMOUNTING: SURFACE

DESCRIPTION VA WIRE BKR P CIR CIR P BKR WIRE VA DESCRIPTION

1592 1 2 1 20 12 540 27,28,29 LIGHTING

TOILET EXHAUST FAN TEF-1 1592 12 20 3 3 4 1 20 12 1080 27,28,29 LIGHTING

1592 5 6 1 20 - - SPARE

1592 7 8 1 - - - PROVISION

TOILET EXHAUST FAN TEF-1 1592 12 20 3 9 10 1 - - - PROVISION

1592 11 12 1 - - - PROVISION

1592 13 14 1 - - - PROVISION

KITCHEN EXHAUST FAN KEF-1 1592 12 20 3 15 16 1 - - - PROVISION

1592 17 18 1 - - - PROVISION

2507 19 20 1 - - - PROVISION

KITCHEN EXHAUST FAN KEF-2 2507 10 30 3 21 22 1 - - - PROVISION

2507 23 24 1 - - - PROVISION

PROVISION - - - 1 25 26 1 - - - PROVISION






PROVISION - - - 1 37 38 - - 13184

PROVISION - - - 1 39 40 3 150 1/0 13184 27LEA

PROVISION - - - 1 41 42 - - 13184

PANEL: 27HEAVOLTAGE: 208/120V

400 AMP MLO3 PHASE/4 WIRE

For all additional calculation summaries, panelboard layouts, and examples of electrical equipment submittals, please see the Electrical Appendix. As the redesign is so extensive, only a sample switchboard has been included for reference within the report. 2.0.5 Protective Device Coordination Study (Short Circuit Analysis) Short circuit ratings are analyzed through a single path within the new 208V building distribution system. Equipment is then sized appropriately. This path includes the utility transformer to Panel 01LNA. Available Transformer Short Circuit kVA: 3750 kVA Transformer Impedance: Assumed 5.0% Calculations are conducted using the “point-to-point” method published by Bussmann fuses. The steps include the following. Step 1: Calculate Transformer Full Load Amperes Ifl = kVA * 1000 SQRT(3)*V Step 2: Calculate Transformer Multiplier Multiplier = 100 / %Z

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Step 3: Calculate Transformer Let-Through Short-Circuit Current

Isc = Ifl * Multiplier Step 4: Calculate “f” Factor f = 1.732 * L * I3ph C * V Where: L=Length (ft) of conductor to fault C = Constant from Table of “C” values for conductors and busway. For parallel runs, multiply C values by the number of conductors per phase. I = Available short-circuit current in amperes at beginning of circuit Step 5: Calculate “M” (multiplier) M = 1/(1+f) Step 6: Calculate the available short circuit symmetrical RMS current at the point of fault.

Iscsymrms = Isc * M Example Calculation to MDP Panel Step 1: Ifl = 3750 * 1000 = 10,409 A 1.73 * 208 Step 2: Multiplier = 100/ 5 = 20 Step 3: Isc = Ifl * Multiplier = 10409 *20 = 208180 A Isc motor contribution = 0 as no motors along this path Itotal sc sym RMS = 208,180 A Step 4: f = 1.732 * 40 * 208180 = 0.2841 11 * 22185 * 208 Step 5: M = 1/(1+0.2841) = 0.7787 Step 6: Iscsymrms = 208180 * 0.7788 = 162116 A

Summarization of Short Circuit Analysis

Equipment Isc (A) Feeder Length f M Iscsym"rms" (A) Equipment RatingMDP 208180 (11) 500 kCmil 40 0.2841 0.7787 162116 200 KAIC

O1HNA 162116 (2) #350 16.5 0.5652 0.6389 103573 200 KAIC01LNA 103573 2/0 7.5 0.6014 0.6244 64675 65 KAIC

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2.0.6 Conclusions

As mentioned in the introduction, the selected alternative for design is the existing dual 480V and 208V system. In comparison, the existing system proves to have the lowest first cost, as it requires smaller size equipment to meet the lower ampere ratings. Despite the need for additional transformers, both dry-type and pad-mounted, lower first cost and the current functionality of the system yield it as the best alternative within the comparison.

2.0 electrical depth - pennsylvania state university

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