Electrical Design Software | Elecdes Design Suite by Scada Systems Ltd

Cable Filling Factor for Raceway, Cables and Wires

Cable Factor Description

The cable factor represents any wire or cable attribute your local regulations require e.g. weight, cross sectional area. The cable factor is used to optimise raceway filling.

  • Each cable or wire has a cable factor representing the amount by which it will fill raceway.

  • Each raceway segment has a cable factor representing the quantity of wires or cables that it can carry.

The attribute or field should contain a number e.g. "3.6", "0.1", "2.400".

You can also use the NEC code to calculate raceway fill for trays and conduits.

The cable factor for a cable can also contain a diameter in addition to the normal cable factor for large power cables that must be placed in a single layer when using NEC filling, e.g. use "2.5 d 1.5in" for a cable with overall cable factor 2.5 and a diameter of 1.5 inches.

CABLEFACTR Attribute and Field or Column

The cable factor is specified in the CABLEFACTR attribute of a raceway segment or field / column in the wire report or cable report. These values can be obtained from the same field or column in the appropriate catalog file.

A tray that can be used to carry either signals cables or power cables when using NEC filling can have the cable factor for signals cables specified in the AUX1 attribute as follows: "SIGNALSCF: 5.7000". The cable factor for power cables remains in the CABLEFACTR attribute. "SIGNALSCF:" indicates this AUX1 attribute data is being used for the "signals cable factor".

Cable Factor use in Route Optimisation

Cable filling factors will be checked as conductors are allocated to routes. Alternate routes must be used if the sum of the cable factors of all conductors presently placed in any part of a route (segment) exceeds the cable factor capacity of that route segment.

The largest conductors (by cable filling factor) will be placed in a route first. The largest conductors will therefore take the optimum routes where available.

Raceway Fill Reporting

The raceway fill percentage is calculated as follows:

 Sum of the cable factor for all wires or cables in a raceway segment / The segment's cable factor.

This value is placed in the FILL_INFO column of the raceway cross section report.

However, if you are using the NEC code for trays and conduits the this calculation is modified according to that code.


A CABLEFACTR of 0.0 allows infinite fill if found on a raceway segment.

A cable or wire will be treated as infinitely small if it is set to 0.0.

Notes on TEEs and Xs

Due to the ability of Tees and Xs to contain more cable than their dimensional width, Tees and Xs should have the cable factor numbers set to 2x the cable factors of the equivalent standard tray.

This is the responsibility of the user.

See also

Use the NEC code to calculate raceway fill for trays and conduits

Panel ducting


How to tune your model for wire and cable routing

Routing functions description

Route optimisation errors and warnings

Power numbers for raceway

Weight filling factor for raceway