Answer Happy

87 CHAPTER 4 Branch Circuits REVIEW Refer to the National Electrical Code or the working drawings when necessary. Where applicable, responses should be written in complete sentences. Complete the following table using the following circuits: 1. Eleven 120-volt duplex receptacles for general use. Receptacle loads are considered to be noncontinuous and are not subject to the 80% load limitation as applied for con- tinuous loads. 2. Ten 120-volt fluorescent luminaires, rated at 150 volt-amperes each. 3. Eight 120-volt incandescent luminaires, rated at 200 watts each. 4. One 240-volt exhaust fan, rated at 5000 watts. 5. One 120/240-volt single-phase, 3-wire feeder, 40-kVA continuous load, originating in a room with an ambient temperature of 100°F (38°C).

compliance based protection based on uipment. have to . If the -nected. even right three right cuits Juc- ble. re Circuit Number Calculated Load in Volt Amperes Calculated Load in Amperes Load Type Load Modifier OCPD Selection Amperes OCPO Ampere Rating Minimum Conductor Ampacity Minimum Conductor Size Type THN/THWN Ambient Temperature Temperature Correction Factor Number of Branch Circuits Required Number of Current Carrying Conductors Raceway Fill Adjustment Factor 14 Conductor Ampacity Before Correcting/Adjusting 15 Conductor Ampacity After Correcting/Adjusting Factors: Circuits 1, 2, 3, and 4 are installed in the same raceway for a distance of 10 ft in an environment where the maximum ambient temperature will be 86°F (30°C). Type THHN/THWN conductors shall be used for all circuits. . Minimum conductor size 12 AWG. Row 1: Calculated load in volt-amperes from problem statements. Row 2: Calculated load in amperes divided by voltage factor. Row 3: Load type: C= continuous; N= noncontinuous: M motor; R = receptacle. How 1 2 4 5 6 7 B 9 10 11 12 13

CHAPTER 4 Branch Circuits Load modifier, 1.25 for C and M load types, 1.0 for R and N load types. Calculated load amperes (Row 2) multiplied by load modifier (Row 4). OCPD rating equal to or next higher standard ampere rating than OCPD selection amperes (Row 5). Ampacity of conductor equal to or greater than calculated load amperes (Row 2). Conductor size with ampacity equal to or greater than calculated load amperes (Row 2). Select from Table 310.16 using the appropriate 60°C for circuits rated 100 amperes or less, and the 75°C column for loads over 100 amperes. From problem statements. From NEC Table 310.15(B)(1). From load calculation. From problem statements. From NEC Table 310.15(C)(1). From NEC 310.16 for conductor type specified in problem statement: (THHN/THWN). Value from Row 13 multiplied by correction and/or adjustment factors. This value must be equal to or greater than the minimum conductor ampacity value in Row 7. Row 4: Row 5: Row 6: Row 7: Row 8: Row 9: Row 10: Row 11: Row 12: Row 13: Row 14: Row 15: