ConduitPro Design

ConduitPro Design

The ConduitPro is a Microsoft© hosted Excel™ spreadsheet program that will assist anyone interested in determining conduit fill capacity, bend radius and maximum pull tensions for horizontal communications cabling. The ConduitPro workbook incorporates eight (8) topic-planning sheets: EIA-Fill, Peter’s-Fill, Peter's Fill Item#1, Peter's Conduit Fills, Circle Packing, Square Packing, Fill-Pull-Bend and Conduit Sizes. 1. The EIA-Fill Sheet can be used to determine conduit fill and bend radius per ANSI/TIA/EIA-569 Standard. The user may designate cable internal diameter and quantity of cables in order to calculate the minimum conduit size per standard. In addition, conduit minimum bend radius can be calculated for installation.

In the above example is Item 1, a 2-1/2" EMT conduit would be required to install 37 - 0.24" OD cables and still be "code compliant".

Item 2 allows ConduitPro to calculate how many cables will fit into an existing standard 2-1/2" EMT conduit.

EIA/TIA Cable OD and Trade Size Conduits

Item 3 below will use the fill parameters to calculate any size conduit (ID known). The Jam Ratio of 4.7 is calculated to help you determine possible install problems.

The minimum bend radius can be calculated for any size conduit.

2. The Peter’s-Fill Sheet can be used to determine standard conduit fill and bend radius per the National Electric Code (NEC) and general code guidelines. The user may designate cable internal diameters of up to four (4) different cables [SPECIAL NOTE: We just have added a special sheet to handle up to ten (10) different cables] and the quantity of each cable in order to calculate the minimum conduit size per standard. In addition, a Jam Ratio (difference between cable OD and conduit ID) is provided that lists the potential for 3 or more cables to jam on bends during the installation process. The user may modify all parameters on all sheets that are color-coded green (safe to use).

Question: What size conduit is required to house (25-0.25" cables, 30-0.2" cables, 3-0.115" cables and 52-0.3" cables? Answer: a 5" Trade SIze EMT conduit, with a 30.6% fill and Jam Ratio of 5.4 for the 70 cables

Calculations used in Peter's-Fill Sheet are more exact than the ANSI/TIA/EIA-569 Standard; which does major rounding of the area and Pi.

Item 2 will allow you to calculate how many cable will fit into a General EMT trade size conduit.
Peter's Fill Item 2

NEC calculations are rounded significantly

Item 3 of Peter's Fill will allow calculations for any size ID conduit with conduit bends

Peter's Fill Item 4 Calculations

3. Peter's 10 Cable
Has 10 cable sets to determine conduit size and fill parameters with conduit bends
10 Cable sets to calculate conduit id required

4. Peter's Conduit Fills -

Item 1 has 5 contiguous conduits and 5 pull boxes to determine: Conduit capacity based on cable OD and the cable count. Start with a known cable count and take away cables at each pull box

ITEM 1 5 conduits and 5 pull boxes
Conduit A and pull box #1
Conduit Fills - Item 1 box 2 and 3
pull box 4 and 5, conduit E and F

Question: Cable OD is 0.125", Start with 1200 cables. Take away 71 cables at box 1, 56 cables at box, 360 cables at box 3, 31 cables at box 4 and 130 cables at box 5.
Conduit A = 7.335 " ID, Conduit B = 7.115", Conduit C = 6.95", Conduit D = 5.685", Conduit E = 5.561 and Conduit F = 5.142". There are 582 left in Conduit F.

Item 2 has 5 stand alone conduit to determine cable fill and conduit requirements

Question: What are the desired conduit ID's of 0.25" OD cables as follows: Conduit "F" has 15 cables, Conduit "G" has 20 cables, "H"-5, "I"-30 and "J" - 1?

Answer: Conduit F = 1.788" ID, Conduit G = 2.025"ID, Conduit H = 1.068" ID, Conduit I = 2.45" ID and Conduit J = 0.344" ID

Item 3

Item 3 has 5 contiguous conduit and 5 pull boxes to add cables to an existing conduit. That existing conduit may have cables already installed so %-used is provided.
Conduit L and M, pull box 1 and 2
input 6.2c1
Adding 5 cables doesn't impact the existing 1.394 " ID conduit (fill % now is 20.9%). The additional 30 cables will reuire a 1.576 " Conduit ID (Fill is now 40%).

ITEM 4

Item 4 has a start box (with up to 4 existing cable sets), 3 pull boxes and 4 conduits (conduit bends, up to 4, are used to calculate the required conduit ID.

5. The Circle Sheet has three (3) special subgroups to determine:
Circle Sheet Item 1: Maximum Cable Count in a conduit based on density packing (near 100% or similar to NASA space packing).

Circle Sheet Item 2: Calculate the diameter of a tangent cable that will fit between two (2) tangent cables and a surface. In otherwords, how many cables will fit into conduit?

ConduitPro Item 2 - 2 cables in a conduit

Circle Sheet Item 3: To calculate what size conduit is required to fit 3 cables of varying outside diameters (OD)

ConduitPro Item 3 - 3 cables in a conduit

6. The Square Sheet Item 1 has three (3) special subgroups similar to the Circle Sheet:

Square Sheet Item 2: To calculate what size cable will fit between 2 cables of known diameter (all touching each other and a surface)

ConduitPro Item 2 - tangent circles to a line

Square Sheet Item 3: To calculate the outside diameter (Cable B) of the cable that will fit in a square corner between a know diameter cable (Cable A = 3") touching the corner edges. Answer- 1/2 " cable.

ConduitPro Item 3 - tangent circles to each other and a corner

7. The Fill-Pull-Bend Sheet also has three (3) special subgroups to determine:
a. The number of cables that will fit into a cable-management trough

b. The maximum allowable pulling tension of a solid copper conductor

ConduitPro Max Pull based on conductor size

c. The bend radius of communications cable. It is possible to group like conductors in order to calculate the straight-run pull tension of various cables such as a 50-pair 22 AWG cable.
In addition, the minimum cable bend radius “Rule of Thumb” is listed for user perusal.

8. The Conduit Size Sheet lists standard conduit sizes, ranging from ½” to 6”. Standard conduit like EMT, GRC, PVC, EB and DB are listed for perusal.

Disclaimer: In all cases, contact the cable/conduit vendor to ascertain exact dimensions and design information. The manufacture's specifications and recommendations supercedes any CablePro calculations.