EC&M’s Electrical Calculations Handbook - Chapter 2 pptx
EC&M’s Electrical Calculations Handbook - Chapter 2 pptx
... voltage
- ( 120 120
°
= - 120 -6 0
°
)
= -( - 120 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
24 00 Volt, 3-phase, 3-wire delta
24 00...
EC&M’s Electrical Calculations Handbook - Chapter 11 pptx
... increase within the
3 12 Chapter Eleven
316 Chapter Eleven
Figure 1 1-3 Solve for minimum conduit size given wire insulation type, wire
size, and wire quantity.
Figure 1 1 -2
Cross-sectional areas of ... so the cross-sec-
tional area available within each type of raceway for the
placement of conductors varies with the type of raceway.
Figure 1 1 -2 on p. 315 shows the available cros...
EC&M’s Electrical Calculations Handbook - Chapter 1 ppsx
... Grounding Systems 21 5
Obtaining the System Grounding Point 21 7
Chapter 8. Lighting 22 1
The Lumen Method 22 1
The Point-by-Point Method 22 3
Indoor Lighting 22 9
Lighting Rules of Thumb 24 5
Contents vii
RESISTOR
CURRENT ... size
4 -2 7 Thermal damage curve for paper or rubber insulation
4 -2 8 Thermal damage curve for thermoplastic insulation
1 2- 1 Time-overcurrent character...
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, ... /1000
kVA = 58. 823
(58. 823 ) = (50.000)
2
+ (kVAR)
2
kVA
2
= KW
2
+ kVAR
2
(58. 823 )
2
- (50.000)
2
= (kVAR)
2
30.986 = (kVAR) is the required ca...
EC&M’s Electrical Calculations Handbook - Chapter 4 potx
... 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 ... 125 100 150
120 170 135
00 145 115
175 135 195
150
000 165 130
20 0 155 22 5
175
0000 195 150
23 0 180 26 0
20 5
25...
EC&M’s Electrical Calculations Handbook - Chapter 5 potx
... 13.8-kV bus.
Fault power is available to flow into this bus from
1. The electrical utility source
2. The 24 -megawatt (MW), 30-MVA generator
3. The 5000-hp motor
4. The 20 0-hp motor
5. The 40-hp ... form in Fig. 5 -2 . First, however, note
that electrical short-circuit power can come from four
sources in this circuit:
1. The 400,000-kVA electrical utility service
2. The 24 -MW, 3...
EC&M’s Electrical Calculations Handbook - Chapter 6 pdf
... power conductors and generator overcurrent pro-
20 0 Chapter Six
Gas-turbine generators arrive at the installation site prepackaged
on skids.
Figure 6 -2
Solve for generator overcurrent protection ... kilovoltampere rating is designed to be
125 percent of the generator kilowatt rating; and this is
20 2 Chapter Six
Diesel engine generator set.
Generator Sizing
Calculations
A generat...
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. ... minimum size of this conductor is
shown in Table 25 0-1 22 of the National Electrical Code. See
Fig. 7-3 for an example problem in sizing the equipment-
grounding conductor.
When feede...
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, ... perpendicular to the lamp.
24 8 Chapter Eight
Figure 8-3
Zonal cavity calculation worksheet.
24 1
Figure 8 -2
Common lamps and their characteristics.
23 4
Footcandles ϭ
The left...
EC&M’s Electrical Calculations Handbook - Chapter 9 docx
... transformer coil.
27 2
26 0
Figure 9-1 0
Table replicating part of NEC Table 45 0-3 (a),
overcurrent protec-
tion of transformers over 600 V.
27 4
Figure 9-1 2
Table replicating part of NEC Table 45 0-3 (b),
overcurrent ... Fig. 9-1 5b.
Note that the output voltage is either 24 0 V ϩ 24 V, or 26 4
V, or 24 0 V Ϫ 24 V, or 21 6 V, depending on whether the sec-
ondary is c...