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Proto wiring V. dcc concersion

Started by r.cprmier, August 19, 2007, 06:45:24 PM

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r.cprmier

On the early Proto 2000 FAs, the wiring is as such:  One lead from the motor is on the frame.  Now, to convert to DCC, it seems that one has only to remove that connection and splice it to the orange lead from the decoder, and run the red lead from the decoder to the frame, considering the frame is common to only one side of the trucks, and the motor frame is isolated from the unit frame. 

Normally, I wouldn't bother ask this question, but would just overhaul the wiring; but out of curiosity, would wiring it that way harm the decoder?  Feedback appreciated.

Rich
Rich

NEW YORK NEW HAVEN & HARTFORD RR. CO.
-GONE, BUT NOT FORGOTTEN!

Hunt

Rich
As long as the frame is part of the Positive (right rail pickup) circuit it will work.

Test to be sure the motor brushes are in fact isolated, i.e. power can reach them by only going through the decoder. Then the decoder will be fine as long as you do not exceed its ampere and volt rating.

Decoder wire color               |   Function
Red                                  |  Right rail pickup
Orange                             |  Motor positive
Black                                |  Left rail pickup
Gray                                 |  Motor negative


r.cprmier

Hunt;
Yep; I ran continuity checks between both brushes each and the frame, the positive side is tied to the fame (zero ohms).  Obviously, that has to be separated and the orange wire from the decoder to the brush, the red wire from the frame to the positive lead on the decoder.  I was actually surprised that Proto used this particluar set-up, considering that the "Erie-builts" were two-wire from each truck.  I also checked the motor casing to frame and got infinity, as well as with the negative brush.  I got the usual resistance across the brushes via the rotor (approx. 11 ohms).  The wrap of the rotor, by the way, intrigued me.  Have you looked at it?  I will be probably using standard four-function decoders on the diesels, as the recip noise would normally be drowned out at any appreciable distance, by any "civilized" din.

Rich
Rich

NEW YORK NEW HAVEN & HARTFORD RR. CO.
-GONE, BUT NOT FORGOTTEN!

Hunt

Rich,
Remember to place a proper resistor in lighting circuit for each light.

r.cprmier

HUnt;
As a matter of practise, I now change everything lighting wise to LEDs, using either a 460 or 700-ohm resistor, 1/4 watt.  There is no maintenence and the lighting is a lot more realistic using yello-glo diodes than bulbs.
Oh, and I did learn what happens to bad boys who do not put a resistor in series with LEDs and apply power anyway...

Some of my stuff has LEDs factory installed that look more like the inside of a Phanotron tube than a light.  THose are pre-ordained for change.

Rich
Rich

NEW YORK NEW HAVEN & HARTFORD RR. CO.
-GONE, BUT NOT FORGOTTEN!

Frankford el car

My rapid transit layout uses pantogrpah collection from live trolley wire, and ceiling-mounted under-running third rail in subway tunnels. A few pantographs arc across momentary air gaps once in a while. If I convert to DCC, will this cause damage to decoders? The under-running third rail is Code 100 nickel-silver rail, inverted at ceiling level, and the trolley wire is 22-gauge copper wire, which has been in use for nearly twenty years.
Chief Superintendent,

Independent Transit Co. (INT Lines)

"Have your transfer ready, for the next stop."

r.cprmier

A make/break connection on the order of an arcing pan just might be harmful to a decoder, only because of the erratic voltage/current draw. Some of the components in that engine are going to be resistive loads, some inductive, and the inevitable direct/inverse proportional effect t hat may or not have on semiconductors.  A voltage dip causing a current surge is usually the death knell for semiconductors not protected.

They're your engines, but for my money, I would go with power from track.

Rich
Rich

NEW YORK NEW HAVEN & HARTFORD RR. CO.
-GONE, BUT NOT FORGOTTEN!

Frankford el car

Converting back to two-rail pick-up, would bemore complicated for me, than a solution. Route on my rapid transit layout with a subway-elevated line, operate's like some in New York, Philadelphia, and Chicago, with a stub-end terminal, a turnback loop in the subway which functions as a reverse loop, a multi-track junction, and a three-tracked el', with the center track used as a reversible express track (traffic direction according to the "AM", or "PM" rush). For me, converting to live overhead with pantograph-collection, actually simplified the track wiring, to noting more than dividing the tracks into electrical blocks. The running rails are electrically joined to each other, in each electrical block.
Chief Superintendent,

Independent Transit Co. (INT Lines)

"Have your transfer ready, for the next stop."