Electrician Calculators

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from the National Electrical Resource Center

Link to Calculator |
Description |

Range Calculator | Select range ratings from 1 3/4 KW to 27 KW and number of ranges and this program determines the demand load using Table 220.55 and Notes 1, 2 , and 3. Loads for up to 1000 ranges can be determined. Nine examples from the NEC, textbooks, and the author are included. |

Table 310.16 Conductor Size | Enter the continuous and noncontinuous load then select the conductor insulation, terminal temperature, ambient temperature, number of current carrying conductors and this program finds the correct wire size and maximum and minimum over current protective devices and the respective size of the equipment grounding conductors. Also includes special condition buttons for nipples, AC/MC cable, equipment rated for continuous loads, and circuit is for receptacles for cord and plug connected equipment. Conductor size is automatically adjusted to the conditions according to the NEC. Results are automatically entered into a voltage drop calculator that calculates voltage drop with an option to increase wire size and proportionately increase the equipment grounding conductor size. Examples and notes on how programs operates are included. |

Table 310.16 Load | Select the wire size, conductor insulation, terminal temperature, ambient temperature, number of current carrying conductors and this program finds the permitted load and maximum and minimum over current protective devices and the respective size of the equipment grounding conductors. Also includes special condition buttons for nipples, AC/MC cable, and circuit is for receptacles for cord and plug connected equipment. The permitted load is automatically adjusted to the conditions according to the NEC. Results are automatically entered into a voltage drop calculator that calculates voltage drop with an option to increase wire size and proportionately increase the equipment grounding conductor size. Notes on how programs operates are included. |

Table 310.16 Parallel | Select the wire size starting at 1/0 AWG, number of conductors in parallel, conductor insulation, terminal temperature, ambient temperature, number of current carrying conductors and this program finds the permitted load and maximum over current protective devices and the size of the equipment grounding conductors. Also includes special condition button for nipples. The permitted load is automatically adjusted to the conditions according to the NEC. Results are automatically entered into a voltage drop calculator that calculates voltage drop with an option to increase wire size and proportionately increase the equipment grounding conductor size. Notes and example on how programs operates are included. |

Motor Branch Circuit | Select motor hp from 1/6 to 500 hp, phase, type of motor, class of service, duty cycle, conductor material type, ambient temperature, number of current carrying conductors in raceway or cable, conductor insulation type, terminal temperature, service factor, and temperature rise. This program then determines motor branch circuit parameters that include wire size, short-circuit and ground-fault protective device normal and maximum values for all four types, conductor size, overload protection size, disconnect size, controller NEMA size, and equipment grounding conductor size when the motor nameplate full load amperes value is entered. Required results are automatically entered into a voltage drop calculator at bottom of page where voltage drop can be calculated that permits increasing the conductor size to lower voltage drop. |

Raceway Fill | Select the wire insulation, wire size, number of conductors, type of raceway, fill type either 25 per cent, 60 per cent or auto and this program finds the correct raceway size. When only three conductors of the same size are selected the jamming ratio is calculated and the user is alerted if the jamming ratio is between 2.8 and 3.2 and the user is given the choice of upsizing the raceway per Chapter 9 Table 1 FPN 2. Five unique conductors can be entered. |

Extended Raceway Fill | This is the same as the raceway fill calculator except the number of unique conductors is entered and a calculator for any number of conductors is custom built in the lower frame. Then select the wire insulation, wire size, number of conductors, type of raceway, fill type either 25 per cent, 60 per cent or auto and this program finds the correct raceway size. When only three conductors of the same size are selected the jamming ratio is calculated and the user is alerted if the jamming ratio is between 2.8 and 3.2 and the user is given the choice of upsizing the raceway per Chapter 9 Table 1 FPN No. 2. Any number of unique conductors can be entered. |

Cable Raceway fill | Enter the number of unique cables and a calculator for the cables is custom built in the lower frame. Then enter the diameter for each cable, select number of cables, type of raceway, fill type either 25 per cent, 60 per cent or auto. This program finds the correct raceway size. |

Voltage Drop | Select the material either copper or aluminum, the size of the conductor, the voltage and phase from a list of common voltages, then enter the one way circuit length in feet, and load in amperes. This program finds voltage drop, per cent voltage drop, and volts at end of circuit. |

Voltage Drop for any voltage | Select the material either copper or aluminum, the size of the conductor, then enter the voltage, the one way circuit length in feet, and load in amperes. This program finds voltage drop, per cent voltage drop, and volts at end of circuit. |

Minimum conductor Size for Given Voltage Drop | Select the material either copper or aluminum, the size of the conductor, the voltage and phase from a list of common voltages, then enter the maximum voltage drop in per cent and load in amperes. This program finds minimum conductor size, voltage drop and volts at end of circuit. |

Maximum Length for Given Voltage Drop | Select the material either copper or aluminum, the size of the conductor, the voltage and phase, then enter the volts, maximum voltage drop in per cent and load in amperes. This program finds maximum conductor length in feet and volts at end of circuit. |

Power Calculator P=ExI | Enter power factor and select single or three phase and kilowatts or watts then enter any two values for power, volts, or amperes and calculate the remaining value. |

Power Calculator P=ExE/R | Enter power factor and select single or three phase and kilowatts or watts then enter any two values for power, volts, or resistance and calculate the remaining value. |

Power Calculator P=IxIxR | Enter power factor and select single or three phase and kilowatts or watts then enter any two values for power, amperes, or resistance and calculate the remaining value. |

Ohm's Law | Enter any two values for volts, amperes, or resistance and calculate the remaining value. |

Grounding Conductor Size | This program reads NEC Table 250.122. Select the overcurrent protective device from the list that includes the standard overcurrent protective device sizes from Section 240.6(A) and this program finds the sizes of both the copper and aluminum equipment grounding conductors. |

Grounding Electrode Conductor Size | This program reads
NEC Table 250.66. Select the size of largest copper service
entrance conductor or equivalent area for parallel conductors from the
list or select size of largest aluminum service entrance
conductor or equivalent area for parallel conductors from the list and
this program finds the sizes of either the copper or aluminum equipment
grounding electrode conductors. |

Overcurrent Protective Device Size | This program reads NEC Section 240.6(A) that lists the standard sizes for circuit breakers and fuses. Select to size up or down and enter the amperes and this program finds the size of the overcurrent protective device. |

Cable Tray Pulling Tension | This program is very extensive and is used to set up long cable pulls in cable tray. Examples are included. |

Raceway Pulling Tension | This program is extensive and is used to determine pulling tension when pulling conductors into raceways. Examples are include. |

Offset Distance Between Bends and Developed Length | This program calculates the precise distance between bends using trigonometry and does not use the inaccurate Benfield method. A developed length calculator is also included. |

Advanced Voltage Drop | This program calculates voltage drop by finding the actual approximate operating temperature of the conductor and using the conductor's resistance at this temperature. |

Excel Table 310.16 Reader | This Excel spreadsheet reads Table 310.16 for copper conductors only. This program is similar to the JavaScript program that reads Table 310.16. |