EC&M’s Electrical Calculations Handbook - Chapter 16 ppsx
EC&M’s Electrical Calculations Handbook - Chapter 16 ppsx
... conversion calculations are encountered repeatedly. Figure 1 6-2 pro- vides the conversion formulas for these common conver- sions, and Fig. 1 6-3 is a set of typical sample calculations showing how to use the conversion ... operation 430 Chapter Sixteen Figure 1 6-3 Use these calculation methods with the conversion formulas of Fig. 1 6-2 . ABOUT THE AUTHOR John M. Paschal, Jr.,...
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EC&M’s Electrical Calculations Handbook - Chapter 1 ppsx
... characteristics 4-2 2 Heat losses of a copper bar from its dimensions and ampere load 8-1 Horizontal footcandle value using point method 4-1 1 Impedance of 600-V, 5-kV, and 15-kV copper cable 1-3 7 Impedance ... Solve for 1-3 0 Power factor from voltage, current, and true power 1 5-2 2 Present value of maintenance cost 1 4-2 Pull-box dimensions for an angle pull 1 4-1 Pu...
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EC&M’s Electrical Calculations Handbook - Chapter 10 ppsx
... 289 300 Figure 1 0-8 : Continuous-duty motors driving a continu- ous-duty load (pp. 300 and 301) Figure 1 0-9 : Continuous-duty motors driving an inter- mittent-duty load (pp. 302 and 303) Figure 1 0-1 0: Continuous-duty ... 1 0-1 0: Continuous-duty motors driving a periodic- duty load (pp. 304 and 305) Figure 1 0-1 1: Continuous-duty motors driving a varying- duty load (pp. 306 and...
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EC&M’s Electrical Calculations Handbook - Chapter 2 pptx
... Volt, 3-phase 4-wire wye Note 5 460 Volt, 3-phase 3-wire delta Note 4 600/347 Volt, 3-phase, 4-wire wye 2400 Volt, 3-phase, 3-wire delta 2400 Coltm 3-phase, 4-wire wye 4160 /2400 Volt, 3-phase, 4-wire ... -j 104 = (180) 2 + (104) 2 Minus Phase b voltage - (120 120 ° = - 120 -6 0 ° ) = -( -1 20 COS 60 -j 120 SIN 60) = -[ (-1 20)(5) -j (120)(.866)] = -[ -6 0 +j 103.92...
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EC&M’s Electrical Calculations Handbook - Chapter 3 potx
... VECTOR 180 - 37.4° AMP 20.9 -1 6.6 +j 12.7 (-X, +J) (+X, +J) (-X, -J) (+X, -J) Step 3. Draw the resultant vector. +X +J -J (-X, -J) NEW RESULTANT VECTOR -1 6.6 +j 12.7 180 ° - 37.4 ° AMP 20.9 (-X, ... (0.576 -j 0.17) x (0.576 -j 0.17) = V; Solve for V. 2. Then, multiply scalars together and add angles. V = (0.6 -1 6.4 ° ) x (0.6 -1 6.4 ° ) V = (0.6 x 0.6) (-1 6.4 ° +...
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EC&M’s Electrical Calculations Handbook - Chapter 4 potx
... ampacity. Conductors 163 DETERMINE AMPACITY FROM NEC TABLE REMARKS 31 0-1 6 OR 31 0-1 7 31 0-1 6 OR 31 0-1 7 UNDERGROUND FEEDER CABLE 31 0-1 6 OR 31 0-1 7 MOISTURE AND HEAT RESISTANT 31 0-1 6 OR 31 0-1 7 31 0-1 6 OR 31 0-1 7 WITH ... 90 2 1-2 5 7 0-7 7 1.08 1.05 1.04 2 6-3 0 7 8-8 6 1 1 1 3 1-3 5 8 7-9 5 0.91 0.94 0.96 3 6-4 0 9 6-1 04 0.82 0.88 0.91 4...
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EC&M’s Electrical Calculations Handbook - Chapter 5 potx
... electrical systems against damage during short-circuit conditions is required by the National Electrical Code (Secs. 11 0-9 and 11 0-1 0). Short-Circuit Calculations 181 For example, in a three-phase ... 30-MVA generator 3. The 5000-hp motor 4. The motors connected to the 480-V bus Short-Circuit Calculations 191 Figure 5-1 Electrical power system one-line drawing for short-cir...
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EC&M’s Electrical Calculations Handbook - Chapter 6 pdf
... power conductors and generator overcurrent pro- 200 Chapter Six Gas-turbine generators arrive at the installation site prepackaged on skids. Figure 6-2 Solve for generator overcurrent protection ... the watt load, and the elec- trical dynamo must be sized to allow selected motors to start while other selected electrical loads are in operation. Except in very unusual electrical system...
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EC&M’s Electrical Calculations Handbook - Chapter 7 potx
... such as a 460-volt (V), three-phase, three-wire delta system, an arc- ing fault that repeatedly restrikes can cause voltage “jack- ing” of up to six times the normal system phase-to-neutral voltage. ... enough equipment-grounding conductors, as shown in Fig. 7-4 . Since system grounding is done at the service-disconnect- ing means, the equipment-grounding conductor and the neu- tral (“groun...
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EC&M’s Electrical Calculations Handbook - Chapter 8 pps
... necessary to use the point-by-point method. The Point-by-Point Method How to make point-by-point calculations Later in this chapter, lighting calculations within areas hav- ing reflective surfaces, ... footcandles from the second luminaire. Sample point-by-point lighting calculations Refer to Fig. 8-1 for sample point-by-point lighting calcula- tions for both the nadir point and a po...
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