AWC Connection Calc vs leaDCalc

Provides users with a mobile approach to calculating capacities for single bolts, nails, lag screws and wood screws per the 2024 NDS. Both lateral (single and double shear) and withdrawal capacities can be determined. Wood-to-wood, wood-to-concrete, and wood-to-steel connections are possible. LIMITS OF USE SCOPE AND LIMITATIONS Connection capacities are calculated on the basis of design provisions in the 2024 National Design Specification® for Wood Construction (NDS®). The calculated capacities are based on the following assumptions and conditions: · Bolts and lag screws must meet the requirements of ANSI/ASME B18.2.1, wood screws must meet the requirements of ANSI/ASME B18.6.1, and nails must meet the requirements of ASTM F1667. · Bolts, lag screws and wood screws must be installed in predrilled lead holes in accordance with the provisions of NDS Chapter 11. · Bolts, lag screws and wood screws must not be forcibly driven into connection members with a hammer or other impact device. · The faces of adjacent connection members are brought into contact when fasteners are installed. · Adequate edge distances, end distances and spacing must be provided for all fasteners to prevent splitting of wood connection members, in accordance with NDS Chapter 11. · Steel side plates with thickness of ¼ in. or greater must meet the requirements of ASTM A36, and steel side plates with thickness less than ¼ in. must meet the requirements of ASTM A653, Grade 33. · Concrete connection members must have compressive strength (fc') of at least 2500 psi. · The on-line Connection Calculator does not specifically address multiple-fastener connections. See NDS Chapters 10-11 and NDS Appendix E for applicable design provisions. · The on-line Connection Calculator does not address fasteners installed at an angle to grain (e.g., toe-nails). See NDS Chapters 10-11 for applicable design provisions. · The on-line Connection Calculator does not address fasteners subjected to combined lateral and withdrawal loading. See NDS Chapters 10-11 for applicable design provisions. · The on-line Connection Calculator does not address connections with gaps or non-structural spacer blocks between members. GENERAL STRUCTURAL GUIDELINES The quality of structural wood products and fasteners and the design of load-supporting members and connections shall conform to provisions of the NDS. The on-line Connection Calculator is based on design equations for lateral loading and withdrawal loading specified in NDS Chapters 10 and 11, along with fastener characteristics specified in NDS Appendix L. The NDS Commentary, NDS Appendices I through N, and NDS Chapters 12-13 provide additional guidelines regarding the design of connections in wood structures. RESPONSIBILITY FOR DESIGN While every effort has been made to insure the accuracy of the information presented, and special effort has been made to assure that the information reflects the state-of-the-art, neither the American Wood Council nor its members assume any responsibility for any particular design prepared from this on-line Connection Calculator. Those using this on-line Connection Calculator assume all liability from its use. This Connection Calculator is not meant to be a replacement for the NDS and does not encompass all of its design options. The American Wood Council On behalf of the industry it represents, AWC is committed to ensuring a resilient, safe and sustainable built environment. To achieve these objectives, AWC contributes to the development of sound public policies, codes and regulations that allow for the appropriate and responsible manufacture and use of wood products. We support the utilization of wood products by developing and disseminating consensus standards, comprehensive technical guidelines and tools for wood design and construction, as well as providing education regarding their application. Contact AWC via email: info@awc.org or connect with one of AWC’s regional building code experts.

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.