Cable ampacity software additional modules allows performing several analyses of interest for cables installations other than thermal analysis. What you need to know about your underground electrical installation. Looking for recommendations of a nehermcgrath software package. Consulting specifying engineer evaluating software. Sick oes3 asic, provides smart background and foreground suppression. These parameters were used by the design engineer in the nehermcgrath method to specify conductor size and such installation details as cable spacing and depth. Nec annex b when you dont have the software and want to do quick. I tried to purchase a software program, so i can do it myself, but have had no luck or response from them on how to purchase the software. Considering the number of calculations needed to determine ampacity using the neher mcgrath.
The program uses the neher mcgrath calculation procedure to determine. Looking for recommendations of a nehermcgrath software. Nmin0006 financial corporation, east coast, in progress nmin0007 internet corporation, arizona, data center. In electrical engineering, neher mcgrath is a method of estimating the steadystate temperature of electrical power cables for some commonly encountered configurations. The neher mcgrath calculations is a method for calculating underground cable temperatures and cable ampacity ratings. Delta td is called the dielectric loss temperature rise and is insignificant for voltages below. The program uses the nehermcgrath calculation procedure to determine underground cable temperatures or cable ampacity ratings for virtually any duct bank or direct burial cable configuration. Dec 06, 20 it is the engineers responsibility to determine if a load factor less than 1. With those modules, the user can evaluate the magnetic flux density at any point on or above the ground of an underground cable installation, determine the positive and zero sequence impedances and admittances for all the cables present in an.
Calculation of the cable ampacity considers only power cables since control cables transmit very little current that has negligible effect to the overall temperature rise. The validation of the results obtained with the cymcap software. The neher mcgrath equation was discovered by two cable engineers in 1957. Nehermcgrath calculations engtips engineering forums. Understanding the nehermcgrath calculation and the ampacity. Solar pv power plant underground cable sizing case study. Nehermcgrath ductbank heating, rho value, cable ampacity. Cyme power engineering software and solutions power cable. The cable was selected based on a maximum operating temperature 75. Server software packages from neher mcgrath calculations, calcware ampcalc, and cyme power engineering software and solutions. Correlations of submersible cable performance to neher mcgrath.
Highlights of the course schedule basic principles of ampacity calculations ampacity, heat generation, heat flow, installation parameters, timetemperature ampacity interaction, neher mcgrath method, iec method, nonstandardized geometries. Pdf refinements to the nehermcgrath model for calculating. Cableizer is completely webbased because we believe saas is the future. This allowed an engineer to look up the appropriate cable size based on current rather than calculating the cable size using neher mcgrath calculations 4. Cable sizing and its effect on thermal and ampacity values in underground power distribution thesis a thesis submitted in partial fulfillment of the requirements for the degree of master of science in electrical engineering in the college of engineering. Fortunately, there are electrical systems and wiring harness engineering. It addresses steadystate and transient thermal cable rating as per the analytical techniques described by nehermcgrath and the international standards iec 287 and iec 853.
Using the nehermcgrath formula in selection of conductor size at the terminations although conductor ampacities calculated using the nehermcgrath formula may exceed those found in a table of allowable ampacities, such as table 310. Detailed graphical representation of virtually any type of power cable. Duct bank heating calculations are essential for critical. Hundreds, if not thousands, of tools, mobile apps, and software products exist in the marketplace, all targeted to electrical engineering professionals. Cable steadystate temperature calculation cable thermal. Cable thermal analysis helps engineers design cable systems to operate to their maximum potential. A fresh look at addressing the future electric grid by carson bates. The parameters chosen should be based on the best available data and engineering judgement. Nmin0005 large software corporation, redmond washington.
Pdf cable ampacity calculation and analysis for power flow. Mcgrath,the calculation of the temperature rise and load capability of cable systems, aiee transactions, part iii. Understanding the nehermcgrath calculation and the ampacity of. There are several software packages available that will calculate the neher mcgrath equations. The neher mcgrath approach for cable thermal calculation approach uses a userdefined load factor, whereas the iec 60287 approach assumes a unity load factor. Yet, the addition of excessive thermal insulation will effect the ampacity of a conductor, especially. Sales engineer software engineer symbol technologies.
But would like to be able to be more scientific about it. Cableizer is a software package for the design of power cable systems using electrical, mechanical, thermal. The neher mcgrath approach for cable thermal calculation approach uses a userdefined load factor. Rather than using software the relies on nehermcgrath, i use a finite element analysis package and build the models. Using electrical system software for engineering projects. Conductor ampacity calculation part eight electrical knowhow. Nehermcgrath calculations busbar electrical 18 jun 02 19. In the neher mcgrath nm equation, delta td, is a term added to the ambient temperature, ta, to compensate for heat generated in the jacket and insulation for higher voltages. Ampacity calculations done be a licensed pe in the projects state are generally accepted by the local ahj. Nehermcgrath nehermcgrath nehermcgrath a growing trend nehermcgrath nehermcgrath nehermcgrath nehermcgrath nehermcgrath nehermcgrath nehermcgrath nehermcgrath nehermcgrath nehermcgrath nehermcgrath nehermcgrath. Sep 22, 2011 using electrical system software for engineering projects much has changed since the days of slide rules and bookcases full of engineering references.
It addresses steadystate and transient thermal cable rating as per the analytical techniques described by neher mcgrath and the international standards iec 287 and iec 853. This nec annex provides application information for ampacities calculated under engineering supervision. This software was developed jointly by ontario hydro hydro one, mcmaster university and cyme international, under the auspices of the canadian electricity association. In electrical engineering, nehermcgrath is a method of estimating the steadystate temperature of electrical power cables for some commonly encountered. Mcgrath were two electrical engineers who wrote a paper in 1957 about how to. In electrical engineering, nehermcgrath is a method of estimating the steadystate temperature of electrical power cables for some commonly encountered configurations. Practical power cable ampacity analysis ced engineering.
This gives me more flexibility in defining the problems and handling unususal. Underground transmission workstation is an epri software product based on standards and techniques including iec 60287 and nehermcgraths paper for cable ratings section 10. Nehermcgrath nehermcgrath nehermcgrath a growing trend nehermcgrath nehermcgrath nehermcgrath nehermcgrath nehermcgrath nehermcgrath nehermcgrath nehermcgrath nehermcgrath nehermcgrath nehermcgrath nehermcgrath since 1985, the use of underground service conductors in canada has grown annually by 1%, on average. It is also critical to hire a professional electrical engineer with expertise in both critical environments topology and on providing neher mcgrath calculations. Despite these differences, all allowable ampacity values found in the code are determined using ieee method 835, which in turn is based on the neher mcgrath method see insert. Any ideas on a company or a person who may be interested in doing this calculation for me.
Software programs usually use neher mcgrath method for the calculation of the cable ampacity. Cableizer is a software package for the design of power cable systems using electrical, mechanical, thermal and environmental calculations. They consider only temperature limited, current carrying capacity of cables. In electrical engineering, nehermcgrath is a method of estimating the steady state temperature of electrical power cables for some commonly encountered. The in particular neher mcgrath model relies on the thermal equivalent circuit technique. Learn how to save design time using the raceway rulebook to autolayout cables within duct banks. Pdf cable ampacity calculation and analysis for power. Heating calculations for electrical duct bank consulting. Learn more about ihs goldfire product announcements.
The nehermcgrath equation was discovered by two cable engineers in 1957. Electrical engineers use powertools to perform harmonic analysis, transient stability analysis, short circuit analysis, and to determine demand load, voltage drop, arcflash hazard analysis and protective device coordination. Oct 14, 2009 embedded intelligence increases photoelectric sensor reliability new ip69krated sick w123 photoelectric sensor with rotating connection withstands washdown environments. Perhaps i can provide some information regarding table 310. The definition of ampacity is given in the national electrical code nec as the. Engineers are often called upon to calculate ampacity and temperature rise of. Embedded intelligence increases photoelectric sensor reliability. Theparameters of the equivalent circuit are by using a simplified 1dmodel of the thermal field. The leader in electrical engineering software chosen by the top 40 electrical engineering firms in the world. The validation of the results obtained with the cymcap software provides increased.
Cable sizing and its effect on thermal and ampacity values in underground power distribution thesis a thesis submitted in partial fulfillment of the requirements for the degree of master of science in electrical engineering in the college of engineering at the university of kentucky by obinna elvis igwe lexington, kentucky. Iec 60287 for cable thermal analysis gives analytical expressions for the computation of the geometric factor of threecore cable insulation, whereas the neher mcgrath. Carefully use the nehermcgrath formula find, read and cite. Fortunately, there are electrical systems and wiring harness engineering tools are available to help companies, large and small, as they tackle new challenges. Electrical system design studies myelectrical engineering. Calculations are in accordance with the industry accepted neher mcgrath calculation procedures. The 50 best electrical engineering software tools pannam. Find out how to determine the optimal cable sizes, physical attributes, and maximum derated ampacity using neher mcgrath method and iec 287 standard. We highly suggest that all results and calculation be made under the guidance of and licence professional engineer that specializes in this type of work. Nehermcgrath are specialized and complicated calculations. Mcgrath,the calculation of the temperature rise and load capability of cable systems, aiee transactions, part iii, volume 76, pp 752772, october, 1957.
This software was developed jointly by ontario hydro hydro one, mcmaster university and eaton cyme international, under the auspices of the canadian electricity. The nehermcgrath calculations is a method for calculating underground cable. By estimating the temperature of the cables, the safe longterm currentcarrying capacity of the cables can be calculated. Performing cables sizing calcs for underground cables according to neher mcgrath method using etap software. Here a group of experts share their experiences and opinions about using electrical system and design software to add value to their engineering projects. Cable sizing and its effect on thermal and ampacity values in. Electrical engineering technologist can also profit from it. Find out how to determine the optimal cable sizes, physical attributes, and maximum derated ampacity using neher mcgrath. Nehermcgrath institute professional engineers certify. Neher mcgrath model 2, which was generalized later by many authors, g. Underground cables need a proper burial nehermcgrath. The ampcalc software has been around for a long time and should give results consistent with the neher mcgrath. It is based on a number of assumptions that simplify the. We have a complicated service for a data center which is being supplied from three 2.
Cymcap software output which is eventually based on the neher mcgrath formula and ieee standard 834 are due to the assumption and the coefficients used are different 12. The prevalence of manual engineering methods in wiring harness manufacturing compounds these challenges, especially as harness complexity increases. Uses the nehermcgrath approach where iec 60287does not apply. Cable sizing and its effect on thermal and ampacity values. We highly suggest that all results and calculation be made under the guidance of and licence professional engineer. View tomas martins profile on linkedin, the worlds largest professional community. The cymcap software is dedicated to the calculation of ampacity and. The neher mcgrath method has been widely accepted as an accurate and relatively simple way to calculate the ampacity of underground cables.
All of our studies utilize the latest software versions offered by skm power tools. The software is an efficient tool for making complex calculation tasks straightforward and easy. The tables in 310 may be used and is designed to be used by electricians but the annex b using the neher mcgrath formula is for engineering supervision only. Conductor ampacity calculation part eight electrical. Bishoy azer senior electrical engineer bechtel oil, gas. The software is suitable for use with windows 7, 8. Neher mcgrath are specialized and complicated calculations.
The nehermcgrath calculations provide a method for calculating underground cable temperatures or ampacity ratings and are derived from the following technical paper. A set of experiments was performed on a direct buried cable to compare with the neher mcgrath method and commercially available software programs. These parameters were used by the design engineer in the neher mcgrath method to specify conductor size and such installation details as cable spacing and depth. Real power engineers is an electrical, power and controls systems engineering firm committed to developing technical business and consulting services by means of assessment, design development and commissioning of electrical power systems. Cableizer is completely webbased because we believe saas. Understanding the nehermcgrath calculation and the ampacity of conductors situation. Iterative techniques based on neher mcgrath and iec287 methods full compliance with north american practice and compliance with iec standards, iec 60287, iec 60228, iec 60853, etc.
Ampcalc is suitable for cable installations utilized in industrial, commercial and utility electrical power distribution systems. Understanding the nehermcgrath calculation and the. It is cost effective, accessible anywhere, easily customisable, has improved interoperability, offers easier installation and. Neher mcgrath calculations busbar electrical 18 jun 02 19. Using the neher mcgrath formula in selection of conductor size at the terminations although conductor ampacities calculated using the neher mcgrath formula may exceed those found in a.
The method is used whether the installations are in ambient air tables 1, 2, 3 and 4, or underground appendix d. It is the engineer s responsibility to determine if a load factor less than 1. Underground transmission workstation is an epri software product based on standards and techniques including iec 60287 and neher mcgrath. Nec recommended software engtips engineering forums. The most important differences between the iec 60287 and neher mcgrath approaches are listed below. A fresh look at addressing the future electric grid by. It addresses steady state and transient thermal cable rating as per the analytical techniques described by neher mcgrath and the international standards iec 287 and iec 853.