Wiring for the Proto Power West chassis

Model Railroader Layouts and layout building
1

Does any one have experience of wiring DCC decoders into Proto Power West chassis? I am having difficulty have already blown two decoders. What is the motor setup, the solder to the frame and to both trucks do. Can someone explain?
Thanks

2

I am not familiar with that particular chassis, but, if it is older, then I would bet that one motor brush is connected to the frame for power. If that is the case, then it would explain the blown decoders. To install DCC on any locomotive, the motor must be electrically isolated from the pick-up. I would bet that the pick-up from one side of the track is connected to the frame and one motor brush is also connected to the frame. What you need to do is to make sure that the ONLY electrical connections to the motor are the orange and grey wires from the decoder. On some locos, that can be a real chore. I’m sorry that I can’t be more specific, but, as I say, I am not familiar with that particular locomotive. But, I do know that many older locomotives did use the frame to bring power to one side of the brush plate on the motor. Athearn blue box diesels have spring clips that hold the brushes in place, and the bottom clip has a little nub that contacts the frame. When I DCC’ed my SD40-2, the decoder I bought had replacement spring clips and I used electrical tape to further insulate the motor from the frame. Try to trace the path that the electricity takes from the wheels to the motor in the original setup on your engine.

3

I have a couple PPW chassis, and they originally had a brass sleeve inserted into a hole drilled in the frame. One of the motor leads was soldered to this brass sleeve. DCC does require that the motor be isolated, so you need to unsolder or cut this wire and hook it up to one of the decoder motor connections (orange or gray wire for wired decoders). It’s usually the bottom motor lead that causes trouble.

4

If I recall correctly, the PPW chassis uses a can motor with 2 terminals. So in theroy it shoudl be easy enough to isolate from the chassis. However, some can motors liek that have one fo the leads connected to the metal can itself. Best to check with a multimeter for continuity between the terminal and the motor case, just to be sure. If the case IS grounded to one terminal, then you have to isolate it from the chassis. i THINK they use a silicon adhesive to mount the motors which means it SHOULD already be isnualted from the chassis. Check for a screw though - if the motor is mounted with a metal screw, there’ the short. Simple fix, replace with the same size nylon screw.

–Randy

5

I put a standard decoder onto a PPW chassis a few years back and found it to be very easy. The important thing to do is to ISOLATE! Check to see that once the motor is installed there is No path for power to the motor other than via the decoder.

Regards

Tim

6

None of my PPW chassis have screws, and I’ve never had a problem with the motor lead wires shorting to the motor case. The motors are mounted with double sided foam tape.

I took a picture of one of mine. It shows the brass sleeve that was originally soldered to the lower motor lead. Now the motor lead goes to one of the decoder’s motor connections, and the chassis (via the sleeve) is now wired to one of the decoder track feeds. The hardest part of changing the wiring is getting to the lower wire. I cut mine at the brass sleeve and ran that piece to the decoder.

It looks like a lot of wires because I like to run a couple extra wires to each side of each truck to provide an additional electrical path. The decoder in this case is a Digitrax DH163A0, mounted directly on top of the motor with foam tape. The electrical tape is mostly to keep the wires somewhat neat.

[img.nr]http://www.dacort.com/trains/images/workshop/UP_3826_decoder_1.jpg[/img.nr]

7

Thanks to so many of you who responded. I have accomplished the project with excellent results.
Thanks again