Electrician Calculators
the premiere site for online electrical calculators
from the National Electrical Resource Center

   


Counter start date: 11/21/2008

NEW:  3-Phase Voltage Drop Calculator with Power Factor
uses data from Table 9 and 8 Chapter 9 of the NEC
See below for link.

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   Description
3-Phase Voltage Drop Calculator with Power Factor NEW  This calculator uses Table 9 and Table 8 data to calculate 8 different voltage drops for comparison.  For 3-phase, 3 wire in PVC, Aluminum, and Steel conduit.
For ease of installation first download and install Visual Basic Express 2008 for free from Microsoft by clicking here.
(SQL server is not required)

Click here to download and install Code Calculators
 

If you do not download and install Visual Basic Express you may need to update as follows.

This program requires that Microsoft.NET Framework 3.5 sp1 be installed on your computer to run. 
If you are using Vista or XP and have updated Windows you should find Framework 3.5 at C:\Windows\Microsoft.NET\Framework\         Click here to download and install .NET Framework

You should also download Power Packs 3.0 by clicking here.

 

 Code Calculators - Absolutely free
no adware, no gimmicks, no hassle.

Click here for screen shots

Includes NEC Table 310.16 and voltage drop, Raceway and Trough Fill, and Voltage Drop applications.  New NEC Table 310.16 conductor size and voltage drop application added on 3/21/2009.  Raceway fill application for cables AND wires.  Auto, 25 percent, 60 percent and custom fill for any percent fill, compact conductors and all insulations and sizes from Tables 5 , 5a and 8 are included.  This application also does trough fill for Auxiliary Gutters and Wireways from 4 x 4 inches to 16 x 16 inches.  This is a dynamic calculator that changes output values as inputs are varied.  The voltage drop application from below is also included.

These are not a web page calculators.  These are Visual Basic Click Once applications that run by themselves in windows. Installation includes a link in the Program Start menu and installs a desktop icon.  This is a Click Once Visual  Basic  application with full uninstall features using the control panel, add or remove programs, uninstall.  This application can be automatically updated as new programs are added to the suite.

Click here to download and install

This program requires that Microsoft.NET Framework 3.5 sp1 be installed on your computer to run. 
If you are using Vista or XP and have updated Windows you should find Framework 3.5 at C:\Windows\Microsoft.NET\Framework\         Click here to download and install .NET Framework

NEW  Free Voltage drop program application.  This is a Windows application that automatically installs and allows uninstall using the Windows uninstall feature.  Print to printer and print preview features are included.  Any voltage up to 1000 volts and distances of up to 5000 feet are allowed.  This is not a web page calculator.  This is an application that runs by itself in windows.  This application is include in the above Code Calculators suite.
Compact Conductor
 Raceway Fill		 This webpage calculator is still online but a more complete raceway and trough fill application is included in the Code Calculator suite.

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 compact conductor sizes can be entered.
Range Calculator NEW  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.   Twelve examples from the NEC, textbooks, and the author are included.
Table 310.16 Conductor Size This webpage calculator is still online but a better NEC Table 310.16 application is included in the Code Calculator suite.

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 450 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

(not for compact conductors)

 This webpage calculator is still online but the raceway and trough fill application shown above is much more complete.

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 of power, volts, or amperes and calculate the remaining answer.
Power Calculator P=ExE/R Enter power factor and select single or three phase and kilowatts or watts then enter any two values of power, volts, or resistance and calculate the remaining answer.
Power Calculator P=IxIxR Enter power factor and select single or three phase and kilowatts or watts then enter any two values of power, amperes, or resistance and calculate the remaining answer.
Ohm's Law  Enter any two values of Volts, amperes, or resistance and calculate the remaining answer.
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 is 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.
Special Neher McGrath Papers PDF files of various classic papers on the current carrying capacity of conductors including the famous Neher McGrath and Samuel Rosch Papers.