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 ... 50 Generator Sizing Calculations 199 Figure 6- 1 Solve for generator site rating given load, temperature, and altitude. tection devices requires unique methodologies. The genera- tor kilow...

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... 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 60 0-V, 5-kV, and 15-kV copper cable 1-3 7 Impedance ... prior written permission of the publisher. 0-0 7-1 4148 0-0 The material in this eBook also appears in the print version of this title: 0-0 7-1 360 9 5 -6...

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... 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] Phase a voltage: 120 = 120 COS 0 ... Volt, 3-phase 4-wire wye Note 5 460 Volt, 3-phase 3-wire delta Note 4 60 0/347 Volt, 3-phase, 4-wire wye 2400 Volt, 3-phase, 3-wire delta 2400 Coltm 3-phase, 4-wir...

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... (0.5 76 -j 0.17) x (0.5 76 -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 ° + (-1 6. 4 ° )) units V = 0. 36 -3 2.8 ° ... 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 RESULT...

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... F 60 75 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 1-4 5 10 5-1 13 0.71 0.82 0.87 4 6- 5 0 11 4-1 22 0.58 0.75 0.82 5 1-5 5 12 3-1 31 0.41 0 .67 ... 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 F...

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... 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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... 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. ... electrode requires a grounding-electrode conductor. The minimum size of grounding-electrode conductor is shown in the National Electrical Code in Table 25 0 -6 6. The size of the groundi...

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... 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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... ratio ϭ V P ᎏ V S N P ᎏ N S Chapter 9 251 Copyright 2001 by The McGraw-Hill Companies, Inc. Click here for Terms of Use 266 Chapter Nine Figure 9 -6 Solve for motor coil voltage in a delta-connected motor ... coil. 272 260 Figure 9-1 0 Table replicating part of NEC Table 45 0-3 (a), overcurrent protec- tion of transformers over 60 0 V. 274 Figure 9-1 2 Table replicating part...

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... 41 50 143 130 65 52 60 169 154 77 62 75 211 192 96 77 100 273 248 124 99 125 343 312 1 56 125 150 3 96 360 180 144 200 528 480 240 192 Figure 1 0 -6 Table of full-load currents for three-phase ac induction motors. Figure ... 1.3 1 4 .6 4.2 2.1 1.7 1.5 6. 6 6 3 2.4 2 7.5 6. 8 3.4 2.7 3 10 .6 9 .6 4.8 3.9 5 16. 7 15.2 7 .6 6.1 7.5 24.2 22 11 9 10 30.8 28 14 11 15 46. 2 42 21 17...

Ngày tải lên: 13/08/2014, 02:21