Proto-Scale 3-2; Is it on PS2 5-volt engines?

I would say always best to use the product number, grab the manual, and go off it VS guessing and hoping a certain series or date included 2rail and 3 rail feature switching.

Using my tried and true 20-3XXX-1 number scheme specific to premier steam(20-30xx-1 is less desirable and likely 5V, 20-312x-1 is more likely to be 3V PS2). -2 was typically used to denote scale wheels (not all engines have a -2 option).

I started using the number system mid range just to get a baseline.

https://mthtrains.com/20-3048-1 Definitely confirmed 5V PS2 earlier engine that does not appear to have 3-2 rail switching capability.

https://mthtrains.com/20-3148-1 is PS2 3V and has the 3-2 rail compatibility

So then a https://mthtrains.com/20-3101-1 Triplex is a PS2 5V and does not have the capability.

https://mthtrains.com/20-3101-1 is also PS2 5V and no 3-2 rail switch

https://mthtrains.com/20-3122-1 is a PS2 3V but not yet with 3-2 rail switching capability

https://mthtrains.com/20-3132-1 is a PS2 3V and does include 3-2 rail compatibility

Again, I would caution going off number alone. Pull down the manual and verify.

20-30XX-1 PS2 5V

20-3122-1 PS2 3V but not yet 3-2 rail

20-3132-1 PS2 3V and has 3-2 rail

I did not exhaustively check the number range for PS2 5V engines (steam), just way too many of a range there.

Again, without knowing the exact engine product number, I did a decent range search and 3-2 rail function appears in 2004 in Premier steam starting at 20-3130-1. There may be an engine I am not aware of that has 3-2 rail in a PS2 5V, but I just do not know of it. Even then, PS2 3V is not a guarantee to be 3-2 rail. Example 20-3129-1 is PS2 3V but not yet with 3-2 rail function.

There seems to be a range that happened in roughly 2004 starting with 20-3118-1 through 20-3129-1 that are PS2 3V but not 3-2 rail. 20-3117-1 appears to be the last PS2 5V in 2003? It's also, according to the manual, not 3-2 rail switching.

@Vernon Barry posted:

Again, I would caution going off number alone. Pull down the manual and verify.

I also caution against believing the manuals in all cases.  I've encountered numerous examples where the board set is misrepresented, and also times when the pictures don't match the actual product.

@gunrunnerjohn posted:

I also caution against believing the manuals in all cases.  I've encountered numerous examples where the board set is misrepresented, and also times when the pictures don't match the actual product.

I’d second that, ….sometimes those manuals can bamboozle you,…..

Pat

Guys, thank you.

So from Vernon Barry's posts (thank you!), if it is marked 3-2 rail it is most likely a 3-volt system.  But check the manual.

Pro tip, look for the 2 pin charging port. Ps2 5V either had no charging port or the tiny coaxial one.

Ps2 3V always has a 2 pin charging jack, some are white, some are black, but again very distinct shape.

another example. Note they can be on the bottom of tenders or under a hatch.