AmpCalc Version 4.0 Program Features for UNDERGROUND Systems

ampacity calculations, Neher McGrath calculations, underground cable system, cable ampacities, ductbank, direct burial
Underground System Layout
All program action centers on the main form with point and click access to all program features.
ampacity calculations, Neher McGrath calculations, underground cable system, cable ampacities, ductbank, direct burial
System Data Input – This dialog allows specification of the type of underground system including concrete encased ductbank, direct buried conduits or direct buried cables.  Ductbank dimensions, depth of burial, number of cable positions, concrete and earth RHOs and earth temperature information is entered here.  An automatic coordinate calculator is available to calculate the coordinates of all cable positions in the system.
ampacity calculations, Neher McGrath calculations, underground cable system, cable ampacities, ductbank, direct burial
Cable Position Data Input – The characteristics of every cable position in the system are specified by accessing the Position Data Entry Dialog box.  At each position a unique identifier can be assigned by the user, position coordinates are specified unless they were already automatically calculated.  The cable library and size data is assigned, duct library and size data if appropriate, System voltage and frequency information, the the important operating parameters of load factor, operating temperature, (if ampacity is to be calculated), or specified amperes, (if cable temperature is to be calculated).  Conduit Fill and Jam calculations as well as impedance calcs, voltage drop and power flows are also calculated once sufficient data has been entered by the user.
ampacity calculations, Neher McGrath calculations, underground cable system, cable ampacities, ductbank, direct burial
Conduit Fill and Jam Calculations – Once sufficient data has been entered, conduit fill and jam calculations are performed and continuously updated as data is changed.  Alarms indicate when limits, which can be altered by the user in the options form, are exceeded.  Any ground and neutral cable not needed for the ampacity calculations can be entered in order to correctly calculate fills.
ampacity calculations, Neher McGrath calculations, underground cable system, cable ampacities, ductbank, direct burial
Impedance and Voltage Drop Calculations  –  
Once needed parameters are specified, cable impedance and voltage drop calculations are performed and continuously updated as data is changed.  Voltage drop or rise is compared against voltage drop and rise limits which are set by the user in the program options form.  Calculations are based on the specified current and the circuit length and load power factor specified by the user.
ampacity calculations, Neher McGrath calculations, underground cable system, cable ampacities, ductbank, direct burial
Circuit Power Quantity Calculations  –  As an extension of the voltage drop calculations, the circuit kW and kVAR flows and losses are optionally available in a dropdown box from the Position Data Entry Form.
ampacity calculations, Neher McGrath calculations, underground cable system, cable ampacities, ductbank, direct burial
Ampacity Calculation Results  –  Cable ampacities can be calculated based on specified temperature or temperatures can be calculated based on specified load amps.  The two solution methods can be utilized within the same system for the same calculation.  For systems with all identical cables, a single ampacity can be calculated applicable to all conductors in the system based on the temperature of the hottest conductor.  Or unique ampacities and/or temperatures can be calculated at each cable position in the system. Ampacity and temperature results are provided on the main form underground system layout.
ampacity calculations, Neher McGrath calculations, underground cable system, cable ampacities, ductbank, direct burial
Reporting  –  Flexibility is provided in easily specifying the information to include in the final report including system layout diagram,  input data, library information, intermediate calculations and calculation results.  Reports can be directly printed out, saved, previewed on screen or exported to PDF, RTF or Microsoft Excelâ„¢ format.

Click to bring up Example PDF Report


ampacity calculations, Neher McGrath calculations, underground cable system, cable ampacities, ductbank, direct burial
Duct Data Library Editor – Existing duct data libraries can be modified or the user can create new libraries.
ampacity calculations, Neher McGrath calculations, underground cable system, cable ampacities, ductbank, direct burial
Cable Data Library Editor  – Existing cable data libraries can be modified or the user can create new libraries.