Electrical Design Software | Elecdes Design Suite by Scada Systems Ltd

How to Configure NEC Filling

Select Preferences from the Paneldes Menu. Choose the Routing: Cables tab at the top of the dialog.

Use NEC Filling

Use NEC Filling will enable or disable the use of the NEC code to calculate raceway fill.

NOTE: NEC filling can be used for plant models created in imperial or metric units.

NEC Signals Power Levels

There are two variables in the Preferences dialog.

The variables are the NEC Signals Power Levels (there are 2). They default to power numbers 8 and 1.

Each setting should be filled with one or more numbers representing the integral power number used for your control or instrumentation (signals) cables and trays. If you do not wish to set one of these numbers leave the box empty. If you want to specify more than two power numbers that represent signals power numbers, separate the numbers with commas. You can enter numbers in either or both boxes and each box can accept multiple comma-separated power numbers.


If the numbers were set to 1 and 8, this would indicate that power levels 1.0 through 1.99 and 8.0 through 8.99 would be treated as NEC signals cables / trays.

Maximum NEC fill for conduits, Power and Signals

Set the maximum fill allowed in a conduit for 1 cable, 2 cables and for 3 or more cables.

The maximum fills in conduit as specified in the NEC regulations are: 53%, 31% and 40% respectively. You can override these maximum fills.

You can specify different maximum fills for signals/control cables versus power cables. Signals/control cables are identified as those matching the NEC Signals Power Levels that are described above.

See also

For a description of how to use the NEC code to calculate raceway fill, see NEC Tray and Conduit Filling.