EC&M’s Electrical Calculations Handbook - Chapter 12 pot

... Non-time-delay fuse 2. Time-delay dual-element fuse 3. Magnetic-only, instantaneous-trip circuit breaker 4. Thermal-magnetic-trip circuit breaker Figure 1 2-1 shows the time-current characteristics of the most ... AMPERES 0.01 0.05 0.1 0.5 1 5 10 50 100 500 1000 5000 10000 INSTANTANEOUS-TRIP MAGNETIC-ONLY CIRCUIT BREAKER 20A TIME DELAY FUSE 0.5 1 5 10 50 100 500 1000 5000 10000 TIME IN SECO...

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... capacitance. 82 72 Chapter Three Figure 3-1 (Continued) -J 45 ° 60 ° +J NEW RESULTANT 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, ... vector. +X +J -J (-X, -J) NEW RESULTANT VECTOR -1 6.6 +j 12. 7 180 ° - 37.4 ° AMP 20.9 (-X, +J) (+X, -J) 142.6 ° (+X, +J) 37.4 ° Step 4. Determine the...

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... 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 0.76 5 6-6 0 ... 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 RESISTA...

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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. ... 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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... be placed i ᎏᎏ (1 ϩ i) n Ϫ 1 420 Chapter Fifteen Figure 1 5-2 3 Solve for the cash-flow diagram of a loan transaction at interest. Figure 1 5-2 4 Solve for the cash-flow diagram of a recurrent savings ... require. This chapter provides insights and templates for use in calculating elec- trical estimates. Electrical Takeoff and Personnel-Hour Cost Estimating Calculating the value of...

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... and capacitor size 1 2-4 Relay selection for large generator protection 1 2-6 Relay selection for large induction motor protection 1 2-5 Relay selection for large transformer protection 1 2-2 Relay selection ... 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-k...

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... 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 + j 120 SIN 0 = [ (120 )(1) +j (120 )(0)] 0 ° = ... 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-...

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... set matches an electrical dynamo with the engine that is kilo- watt rated at or above the maximum engine kilowatts and is rated in kilovoltamperes at 125 percent of its kilowatt rat- ing. (This ... 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 prote...

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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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