Cablesizer | Cable Sizing to IEC and NEC Standards

http://www.cablesizer.com/nec/report/[1/8/2013 2:33:35 PM]

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NEC / NFPA 70: National Electricity Code (2011)

AmpacityVolt DropReport

NEC Cable Sizing Report

Important Note: If you change the common input data (e.g. basic cable and load information) on onepage, make sure to run all of the relevant calculations again!

Basic Information

The following basic cable specification was selected:

Conductor material: CopperNEC Cable type: THHNNumber of cores: Multi core

The following load parameters were selected:

Load type: Service, Feederor Branch Load

Number of phases: Three phaseNominal load voltage: 208 VFull load power factor: 0.85 puContinuous Load: 51 ANon-Continuous Load: 0 AProtective Device Rating: 100 A

Ampacity Considerations

Cable installation method: Raceways

The cable is installed under the following conditions:

Ambient Temperature: 95.0°F (35°C)Conductor Temp Rating: 194°F (90.0°C)No. of grouped current-carryingconductors: 4 to 6

Given these installation conditions, the adjustment factors are as follows:

Ambient Temperature: 0.9574 NEC 2011 Article 310.15(B)(2)Grouping derating: 0.8 NEC 2011 Table 310.15(B)(3)(a)

Cablesizer | Cable Sizing to IEC and NEC Standards

http://www.cablesizer.com/nec/report/[1/8/2013 2:33:35 PM]

Total derating factor: 0.7659

125% x Continuous load + 100% x Non-Continuous load is 63.75 A. The protective device rating is 100 A.

The ampacity calculation is based on the larger of these two values, i.e. selected load current = 100 A

Result: For the selected load current: 100 A:

Minimum Multi Core cable size is: 1 AWGCable base ampacity: 145 A (NEC 2011 Table 310.15(B)(16))Installed / derated ampacity: 111.0555 A

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