Wire and the Wire Database

This Section Describes Creation of Wire Databases For Use With The Wire Pull Calculator.

GTP includes a sample wire database named 'WireWorks' with the software that can be referenced in your feeder schedules. While based on actual wire data, GTP does not guarantee or accept responsibility for its validity. Wire databases should be created by the user prior to utilizing the wire pull calculator. The wire database spreadsheet template is included and new files may be created via the Setup dialog. There is a sample custom database in the Download Files and Documents shortcut on the left-hand toolbar. It is called "CustomWireDB" and is identical to the hardcoded database in WireWorks.

Spreadsheet Files

Each wire database (except WireWorks) is stored as a separate Excel workbook in the wire database folder configured in the Setup dialog. The wire database files may be shared by placing the folder on a shared network drive. This forces each database to have a unique name.

Spreadsheet Tabs

Separate tabs may be used to organize wire by type or manufacturer within the wire database spreadsheet workbook, but all rows will be combined by the software into a consolidated list.

Spreadsheet Columns

These are the required columns:

It is important to note that the ID column must have unique values as compared to all other rows in the entire workbook.
Semicolons (;) should not be used in any wire data fields.
After saving an update to a wire database spreadsheet while Revit is running, just open the Setup dialog and click OK. This forces the wire databases to be reloaded into Revit.

Importing Wire Information

To automatically set wire quantities and sizes for conduit runs based on feeder schedule data, the field wire Database, Wire Quantity, Wire Size, Wire Type, and Wire Insulation must be mapped to an Excel column. We also offer mapping options for Ground, Phase, and Neutral entries to be mapped to their Quantity, Size, Type, and Insulation to the same or unique Excel columns. The values supplied by these fields should match data exactly as entered in a registered wire database.

CALCULATION METHODS

Variables

D = Inner diameter of conduit, in inches

d = Outer diameter of wire, in inches

Tin = Pulling tension into a section, in pounds

Tout = Pulling tension out of a section, in pounds

w = Weight correction factor, dimensionless

u = Coefficient of dynamic friction, dimensionless

W = Total weight of cables being pulled, in pounds/ft

L = Length of straight section, in feet

@ = Rise or fall angle of straight section from horizontal, in radians

& = Angle of bend, in radians

R = Bend radius measured to inner wall, in feet

e = Base for natural logarithms, a mathematical constant ~ 2.72

SP = Sidewall Pressure in pounds/ft

N = Number of wires

C = Configuration [Single, Triangular, Cradled, or Diamond]

if # wires = 1,
configuration = Single

if # wires = 2,
configuration = Triangular

if # wires = 3,
If [Conduit Inside Diameter / Sum Wire Diameters] < 2.5, configuration = Triangular
If [Conduit Inside Diameter / Sum Wire Diameters] >= 2.5, configuration = Cradled

if # wires = 4,
If [Conduit Inside Diameter / Sum Wire Diameters] < 3, configuration = Diamond
If [Conduit Inside Diameter / Sum Wire Diameters] >= 3, configuration = Cradled

if # wires > 4,configuration = Complex

SF = Safety Factor (default to 60%)

for horizontal straight sections, Tout = w * u * W * L + Tin

for inclined straight sections, Tout = +/- W * L * (sin @ +/- w * u * cos @) + Tin

where +/- is + for rising pulls and - for descending pulls

for vertical applications, same formula applies, but can be simplified to +/- W * L

for bends, Tout = Tin * e^(w * u * &)

for weight correction factor, w

if configuration = Single, w = 1

if configuration = Triangular, w = 1 / sqrt(1 - [d/(D-d)]^2)

if configuration = Cradled, w = 1 + 4/3 * [d/(D-d)]^2

if configuration = Diamond, w = 1 + 2 * [d/(D-d)]^2

for sidewall bearing pressure, SP

if # wires = 1, configuration = Single, SP = Tout / R

if # wires = 2 or 3, configuration = Triangular, SP = w * Tout / (2 * R)

if # wires = 3, configuration = Cradled, SP = (3 * w - 2) * Tout / (3 * R)

if # wires = 4 or more, configuration = Diamond, SP = (w - 1) * Tout / R