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".

Reserved Spare Cable Factor (%)

Paneldes allows you to choose a percentage of cable factor as Reserved for Future Cables ( for overall model or for each power split used in each individual raceway segment ) so that routing will fill only the remaining "unreserved and unused" cable factor of each segment.

  • Reserved CF for any individual raceway segments can be specified in the AUX1 attribute as follows CFRSVD:10, 20; where "CFRSVD:" indicates that AUX1 attribute data represents the "Reserved cable factor percentage" e.g. If the tray has a cable factor 200 and it is split-up into two parts (30%) signals cables and (70%) power cables, then the routing will fill up to the remaining CF for each split i.e. 60 - 10% = 54 for signals and 140 - 20% = 112 for power cables.

  • You can choose to reserve a CF for each power split for raceway segments in the same order of power splits e.g. CFRSVD:10, 20, 10, 35; where first power split will have 10 % as Reserved CF, second power split will have 20% as Reserved and so on.

  • Reserved CF for an overall project can be set from the Preferences under Reserved Tray Capacity.

Note: If "CFRSVD" has been specified in AUX1 attribute in a raceway segment then the Reserved Tray Capacity for the overall project is ignored for that raceway.

Note: Reserved Spare Cable Factor can also be referred to as DERATE percentage, as it allows Paneldes to change/de-rate the cable factor for raceways.

Conduit segments do not normally reserve any space as spare since cables can only be pulled through a conduit together, not in separate batches. If you have conduits that allow cables to be pulled in multiple batches (AUX6 is "MULTIPULL") then those conduits will reserve space according to the global setting the same as other segment types. Specifying "CFRSVD" in AUX1 of a conduit automatically marks that conduit as allowing cables to be pulled in multiple batches.

Used Cable Factor (%)

Paneldes allows you to choose a percentage of the cable factor as Used by Existing Cables ( for overall model or for each power split used in each individual raceway segment ) so that routing will fill in only the remaining "unreserved and unused" cable factor of each segment.

  • Used CF for any individual raceway segments can be specified in the AUX1 attribute as follows: CFUSED:10, 20; where "CFUSED:" indicates that AUX1 attribute data represents the "Used cable factor percentage" e.g. If a Tray has cable factor 200 and it is split-up into two parts (30%) signals cables and (70%) power cables, then the routing will fill up to the remaining CF for each split i.e. 60 - 10% = 54 for signals and 140 - 20% = 112 for power cables.

  • In another scenario, if AUX1 contains "CFUSED:40, 10; CFRSVD:20, 5;", then the maximum fill for routing is the remaining CF i.e. 60 - 60% (CFUSED + CFRSVD for signals split) = 24 for signals and 140 - 15% (CFUSED + CFRSVD for power split) = 119 for power cables.

  • You enter a Used CF for each power split for raceway segments in the same order of power splits e.g. CFUSED:10, 20, 15, 35; where first power split will have 10 % as Used CF, second power split will have 20% as Used CF, third will have 15%, and so on.

  • Used CF for an overall project can be set from the Preferences under Used Tray Capacity.

Note: If "CFUSED" has been specified in AUX1 attribute in a raceway segment then the Used Tray Capacity for the overall project is ignored for that raceway.

Conduit segments cannot normally have any space marked as used since cables can only be pulled through a conduit together, not in separate batches. If you have conduits that allow cables to be pulled in multiple batches (AUX6 is "MULTIPULL") then those conduits will have space marked as used according to the global setting the same as other segment types. Specifying "CFUSED" in AUX1 of a conduit automatically marks that conduit as allowing cables to be pulled in multiple batches.

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 + Used cable factor capacity ) / 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 then this calculation is modified according to that code.

CABLEFACTR 0.0

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

Raceway

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