Electrical/Electronics Standards

     A. Wire Size - AWG

     B. Wire Termination

     C. Terminal Strips

     D. Power Supplies

     E. Trolley Considerations

     F. Building Lighting



A. Wire Size - AWG


  1. Cab buss wire shall be at least 14 AWG stranded from power supply source to the control panel. Blue ring lugs shall be used for termination. Cab metering wire shall be 14 AWG stranded from power supply source to the meter connection. Special blue ring lugs must be used at the meter end.
  2. Block feeder wire shall be 14 AWG stranded from the control panel to within 2 ft of the rail connection. Blue spade lugs will be used for termination.
  3. Rail feeder wire shall be no smaller than 24 AWG stranded from the rail connection to the block feeder terminal block. Red spade lugs will be used for termination.
  4. Turnout control shall use only Beldon type 8444 or 8445 cable from the control panel to the turnout terminal block. Red spade lugs will be used for termination.
  5. Throttle controllers shall use telephone quad cable (red/grn/yel/blk) 24 AWG solid from the power supply source to the controller modular jack.
  6. Building lighting buss shall be 18 AWG. See Building Lighting section.

B. Wire Termination


  1. All wiring external to the control panel will terminate on barrier terminal strips, and use insulated crimp lugs. Lugs must be crimped using a "dimple" type crimp tool.
  2. Only two lugs may be connected to a single screw on a terminal strip. If additional connections are necessary (such as rail common), jumper plates may be used.
  3. Rail feeder wire shall be soldered to the outside edge of the rail. Weathered rail must be cleaned with a mototool cutoff disk and pre-tinned prior to connection. Between ¼ and ½ inch of wire must contact the rail.
  4. Every section of rail shall have a rail feeder wire. Rail joiners shall not be relied upon for electrical connection.
  5. Wire splices shall not be allowed.
  6. Whenever any replacement wire is installed, the replaced wiring must be removed.

C. Terminal Strips


  1. Only double row barrier terminal strips may be used.
  2. Drywall screws may be used to attach terminal strips but must not be overly tight. Care must be exercised to prevent breaking terminal strips.
  3. Terminal strips must not be attached directly to the I-beam web. 1" pine lumber must first be glued to the web as a foundation for the terminal strip.
  4. Block number, turnout number, and/or special connection information shall be written in the vicinity of each terminal strip.
  5. Terminal strips must not be installed in any location where later servicing might be difficult.

D. Power Supplies


  1. Main line power supplies must be capable of 12 volt output with 5 amp continuous load.
  2. Main line power supplies shall be equipped with 5 amp fast-acting circuit breakers.
  3. Branch line power supplies shall be Innovator commercial supplies rated at 4 amp load. Innovator throttles contain built-in short circuit protection.
  4. Branch line power supplies must be configurable to either 2-rail or trolley (both rails at same potential). Use of one throttle on trolley shall not interfere with another throttle being used for 2-rail operation.
  5. Narrow power supplies shall be Innovator commercial supplies rated at 2 amp load or greater. Innovator throttles contain built-in short circuit protection.
  6. Switch machine power supplies are equipped with a 4 amp fast-acting fuse. If a fuse blows, submit a bad order with as much information as possible to isolate intermittent problems. Replacement fuses are kept in the electrical locker.
  7. Lighted structures may have an individual power supply or use an area lighting supply. Do connect switch machine power to structure lighting, even for a test.

D1. DCC Specifications


  1. The layout shall use NCE Command Stations for DCC control. NCE controllers (cabs) must be used exclusively. The club shall provide spare cabs for visiting operators if needed.
  2. A separate NCE Command Station shall be installed on a dedicated programming track.
  3. Each physical mainline panel shall be equipped with a 10 amp DCC booster.
  4. A separate 10 amp booster shall be provided for the branch line.
  5. A separate 10 amp booster shall be provided for the narrow gauge.
  6. Enough DCC cab jacks (plug-ins) shall be installed so operators can easily gain control of locomotives.
  7. Cab jacks must have enough power in a district to operate 5 to 10 NCE "hammerhead" cabs. If required, auxiliary buss power modules must be installed.
  8. DCC boosters and conventional DC supplies must be electrically isolated at all times.

E. Trolley Considerations


  1. Throttles configured for trolley shall use the trolley contact wire as power common.
  2. Automatic loop turnout control must operate with either pole or pantograph equipment.
  3. The trolley interlock at the Market St. main line crossing will prevent trolley collisions from either direction. The interlock release must be manually held until the trolley is completely across the crossing.
  4. Trolley wire is lower than NMRA clearances in most places. This restricts certain equipment such as double stack intermodals from operating on any electrified portion of the railroad.
  5. Only optical track occupancy detectors will function on trolley configured blocks.

F. Building Lighting


  1. All building will use 12 DC Power.
  2. All lighting will use LED lights.
  3. Current limit resistors must be incorporated into the building.
  4. Series lighting is discouraged.
  5. Max current per building is 250ma.
  6. Connections will be via lug terminals, 24 inches long min. from base of building.
  7. All lighted buildings will have a LIGHTING PLAN summited to the Lighting or Electrical Committee before the building is completed.
  8. Existing buildings with working lights are exempt from this spec.
  9. Any building that has lights that are not connected MUST meet this spec.
  10. Exceptions to this spec will be discussed on a case by case basis.
  11. Building lighting power supplies shall be 12 volt / 4 amp identical to switch machine power supplies.
  12. Power buss wiring from a power supply to each building connection shall be 18 AWG wire as follows:
  13. Building power supplies shall be switched off when panel power is removed.


References


NMRA Standards - Standards and Recommended Practices
NMRA Standards - TRACTION Power Collection S-5
NMRA Standards - Electrical S-9
NMRA Recommended Practices - Electrical RP-9



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