Ugly's Electrical References vs leaDCalc

The Ugly's Electrical References App has been updated to reflect changes to the 2026 National Electrical Code (NEC) and the 2026 Edition of our popular Ugly’s Electrical References book. The Ugly’s App offers the most pertinent, up-to-date digital information for electricians, including table change information, mathematical formulas; National Electrical Manufacturers Association (NEMA) wiring configurations; a conduit bending guide with videos, ampacity and conduit fill information, transformer and control circuit wiring diagrams, and conversion tables. The 2026 Edition: * Reflects changes to the 2026 NEC * Features expanded coverage of the following topics: * Full-load currents for 3-phase transformers  * Maximum number of conductors in electrical metallic tubing for trade sizes 5 and 6  * Equipment grounding conductors  * General lighting loads for non-dwelling occupancies  * Overview of important NEC code changes from 2020, 2023 and 2026  Electricians and electrical professionals have used ‘Ugly’s Electrical References’ book as their on-the-job reference for over 35 years. This app will serve you even better in the field today.  FEATURING Calculators and Interactive Features • Ohm’s Law Calculator • Voltage Drop Calculator • Ampacity Calculator • To Find: Amps, Watts, Horsepower, KVA • To Find: Inductance, Impedance, Reactance • Three-phase AC Motor Data: Starter, Breaker, Heater, Wire, and Conduit Size • Power Factor Correction • Full Load Current for Motors and Transformers • Locked-Rotor Current Calculator • Offset Bending Calculator • Conduit Fill Calculator • Conversions for Area, Length, Temperature, Time, Volume, and Weight • NEMA Wiring Configurations *Pinch & Zoom for improved readability *Conduit Bending Video Tutorials *Search function helps you quickly find what you need to know *NEC Updater outlines and explains changes to the National Electrical Code© *Electrical Safety including definitions, boundaries, procedures, PPE guidance, and life-saving *First aid procedures *Blueprint symbol identifier *Bookmark your commonly used screens *High-definition images and interactive tables that can be zoomed in for detail *Works offline *Great for electricians, students, engineers, contractors, maintenance workers, and military Interested in a buying more than one copy of the Ugly’s Electrical Reference app for your commercially owned devices? Please email info[at]uglys[dot]net for details on volume purchases. Privacy Policy - http://www.jblearning.com/privacy/ Terms of Service - http://www.jblearning.com/use/ Support – http://www.uglys.net/appsupport The Ugly’s Electrical Reference app is part of the popular Ugly’s Professional Reference® series, which is an imprint of Jones & Bartlett Learning. National Electrical Code and NFPA 70 are registered trademarks of the National Fire Protection Agency and are not associated with Ugly’s Electrical References in any way.

Application based on the Western Electric Co. Inc, Bell Laboratories, Bell System DC Power Lead Calculator which is in a circular slide rule format.   Using allowable voltage drops specifically designed for telephone company central office direct current power plants and distribution wiring. The application references 48 volt battery systems but also works for other direct current voltages such as 24 volt. When using for 24 volts or other, choose by the required loop voltage drop instead of the specific section of the circuit. Notes: 51. Voltage drop and wire size calculations are based on 2.00 volt LOOP drop from the power plant battery to the load equipment and return. 1.75 Final Volts Per Cell or 40 volts min. operating volts at the equipment for nominal 48V systems.
 (40 + 2 = 42 / 24 = 1.75fvpc) 

 52. LOOP length is used in the calculations, often the battery and returns are unequal length. The result VD is shown as ONE WAY.

 53. The formula used in the lead size calculations is:
CM = LoopLength * 11.1 * Fuse or Breaker @ 100% / VD
(T-Mobile does use 80% of the input breaker or fuse size to calculate DC power wires)
CM = LoopLength * 11.1 * Fuse or Breaker @ 80% / VD
For example the Bell System might use the leaDCalc recommended 66% of the input breaker or fuse size to calculate DC power wires. The Bell System terms Peak and Busy Hour are antiquated electro-mechanical switch central office terms so leaDCalc recommends using 66% of the input fuse or breaker size, ie. 600A fuse or breaker calculate using 400 amperes and which is exactly as was done at Western Electric Co., Inc. for Bell System Telephone offices. 54. BDFB is a Battery Distributing Fuse Board. Fuse Panel is rack mounted at or near the load equipment. Load Equipment is the actual device requiring power. 

 55. This application is intended for informational use. Based on the original Bell System Lead Calculator, Western Electric Co., Inc. Model GS-5420, 4-66.

 56. "leaDCalc" is NOT affiliated with any person or company or anything else anywhere. No how, no way. 
Especially NOT T-Mobile nor the Bell System or even Western Electric Co. Inc., all of whom are mentioned. 
This application is meant as a guide only in determining the size and or capacities of power wiring used in direct current (DC), charging and storage battery telephone systems. 
This application is NOT intended to decide what type of wire, (or if you should even use wire or busbars in your DC systems), no how, no way and it is not for use with alternating current (AC) systems.