Noy long ago I purchased an HO Tenshodo Challenger which was built in the late 1970's I am told. Other than lightly oiling the rods and valve gear I have not until now had the locomotive apart. This engine is heavy and it runs like a charm. I pulls all of the passenger cars I can place on it without any problems, and that is with a 2% grade.
I decided to add DCC and sound to this unit.
This morning I took the superstructure off of the frame, and there are two electric motors installed on this locomotive. The only other mallet engine i have is an old Sierra and that only has one engine.
Do I need to get a dcc decoder that will handle more amperage than the usual electrical load one would expect from one engine?
These are can motors from the 1970's and I am told that I would be better off buying replacement electric motors as they draw less than half of the old motots.
Please advise.
You can do a stall test to see just how much the motors draw. If is less than 1 amp I would think that you could use any sound decoder. You need to stall and measure while both motors are running (or stalled) Who's decoder were you thinking about using?
No need to repower unless the motors draw over the 1 amp. With one decoder you are going to have to work with the CV's that control the BEMF or turn it off. Other wise I think they will fight one another.
Was not sure how reliable a stall test would be by testing each engine individually on the engine.
I used another Tenshodo steam locomotive for the test, I swapped out the motor on a Tenshodo GN 4-8-4 for the test.
The first motor tested stalled out and started to slip at .85 amps and the other at .87 amps.
From talking to one of the techs at QSI it is recommended to replace the two motors with new motors whch have substantially less power requirements.
I think I will forget about dcc and sound for the interim, my layout swaps over to DC very easily so I can run my older DC brass engines without any problems.
When finished with the old brass the switch back to DCC is very easy as well, so I can run my sound equipped newer engines.
Not sure what you mean when you say stalled and started to slip. A stalled motor will not be turning at all.
But with the numbers you posted it look like the amps the two motors would draw is too much for most decoders.
Well I no longer have to ponder what to do about having two electric motors to wire to DCC/sound decoder.
I have an option to accept another challenger that has been converted to DCC/Sound and some money, or just take money for the Challenger.
Apparently my information about the year the challenger was built was wrong, as this challenger has two motors and some sort of special gearing it is fairly new and worth considerably more than I paid.
As you probably can guess a have two collectors who both want this engine.