Electrical Standards

Section 2 – Electrical Standards

Note – this section is very much a work in progress, and by no means finalized.

Section 2.1 – Color Codes

2.1.1 – Twisted Pair Cable Jacket Colors
Any Cat5 twisted pair cables shall use the following jacket colors to signify their application on the layout:

  • Yellow – LED Lighting Control Bus
  • Green – MRBus
  • Orange – NCE Cab Bus
  • Grey – Miscellaneous bundled wiring (signals, switches, control panels, etc.)
  • Blue – Ethernet
  • Purple – RS232 serial (DCC command station to PC and layout control computer)

2.1.2 – Individual Conductor Colors
Individual conductor colors apply to conductors that are not part of any cable.  (For example, a blue wire inside a twisted pair cable is categorized by the cable’s jacket color, not the fact it’s a blue wire.)

  • White/Clear (all sizes) – Track Power A
  • Blue (all sizes) – Track Power B
  • Brown (22-26AWG) – Track frog/points power
  • Black (all sizes) – Ground
  • Red (all sizes) – +9 to +15V aux power
  • Yellow (all sizes) – +24V aux power distribution

2.1.3 – Modular Connector Pinouts

Wherever twisted pair cables are terminated into modular jacks, it is required to adhere to the following termination color codes unless there is an overriding electrical reason to do otherwise:

  • 8p8c (RJ45) connectors:  Terminate per TIA/EIA-568-B

Section 2.2 – Wire Marking

Section 2.3 – Track Connections

2.3.1 – Track Rail A & B
Track Rail A shall be defined as the front (nearest the benchwork edge) rail on the lower deck (Cordova – Abercrombie Canyon) or the rear rail on the upper deck (Chitina – Kennecott).  Track Rail B shall be defined as the rear rail (nearest the wall) on the lower deck and the front rail on the upper deck.

2.3.2 – Track Section Isolation
All independent track sections shall be isolated by insulators placed in both rails.

2.3.3 – Track Feeders
All track sections longer than 3 feet shall have two or more redundant sets of track feed wires.  Track feeders shall be 24-26AWG, and be no longer than 2 feet before connecting with either a device or a 18AWG or larger track power bus wires.


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