We are rewiring a railcar and I am looking for electrical wiring standards that apply to steel coaches. Is there such a standard?

The National Electric Code would apply to all electrical installations. But it does not have a section specifically for mobile vehicles such as automobiles and railcars.

Matt Helton

You don't say what car or at least what railroad the car came from. Is it 32 volt DC, 64 volt DC, 110 volt DC or perhaps Amtrak 480 VAC 3 Phase? So even knowing what voltage you are starting with creates a question. Various railroads more-of-less standardized on one voltage, but not always.

Even within a car, there might be multiple voltages. For instance, post-war PRR Pullman equipment likely would have 220 VAC 3 Phase (lounge and room lights, air conditioning blower fans, refrigerator compressors, and condensor fans), 220 VAC single phase, 110 VAC 3 phase (hall lights) , maybe 110 VAC single phase (outlets in washrooms), 110 DC (air conditioning compressor motor, buffet lights, vestibule and emergency lights) , and 32 VDC (marker lamps). Then there is the question whether the car has been modified at some point along the line, perhaps by a post-railroad owner.

Last time I looked, the National Electrical code, on the first page, if not the first paragraph, said "Not for railroad equipment" or words to that effect. Someone with handy access to the document might check it. I don't have a copy at hand.

The American Public Transit Association likely has a standard for wiring railcars and components in their collection of recommended practices, maintenance standards, etc. They have a web site -- www.apta.com and you can eventually work your way to their PRESS (Passenger Railroad Equipment Safety Standards) section. Also the IEEE quite likely has something which would covers railroad passenger cars. The folks at the Illinois Raiway Museum, at Unio(IL) have a great library of Pullman drawings and schematics. If you have a Pullman built car, that would be a place to start looking. You cannot wire a passenger car like a house, that's for sure.

"Solid conductor" THNN romex wire doesn't work very well in railroad cars, for very long anyway. Railroad vibration has a way of finding the weak points in "residential" quality electrical fixtures. I've seen rail cars wired with 220 VAC Single Phase with the neutral going to a chassis ground. Very exciting when the first short occurs. Usually, the (+) and (-) sides of a DC circuit are protected by fuses or breakers. Similarly, all legs of AC circuits are protected by breakers -- but there are exceptions.

Before you get too far down the road, find somebody who knows their way around this stuff and be very sure of what you are doing and why you are doing it.

G.F.P.
PRR 8404 and PRR 8369

I have a feeling that whatever specs. or standards APTA has put together will reference other organizations such as the AAR and NFPA.

For example, AAR has a standard for wire and cable for railroad vehicle application-which of course , should always be stranded !!!

NFPA, the National Fire Protection Association probably has some standards or recommeded practices for railroad vehicles. They have their finger in many pies relating to the issue of fire protection and the general public.

As for wiring devices, there is are outlets, switches, etc. that are referenced in the trade as 'specification grade'-i.e., heavy duty. They are suitably marked as to be impossible to confuse with the 69 cent outlets sold in Home Depot.

In hindsight, this entire issue sounds like a liability minefield. No wonder the various transit operators hire consultants such as STV or LTK to write their vehicle specs.

DPK

You definitely want to use multi strand wire (like 19 strands or more) rather than single conductor copper wire. Copper will work harden from vibration and fracture. Also consider 'overdoing' the insulation choices, depending on space available. I believe there is a product sold as 'locomotive' wire or some such that is super flexible, multi strand, and has a hypalon insulation rated at 1000 v. And as others have said, AC and DC requirement ARE different.

Bob Kutella