Can you run a DCC equipped loco on DC test only

maxi-model

maxi-model

UK/US/ROW steam narrow gauge railways 1:1
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I have recently acquired a very clean Bachmann 2 truck (die cast) Shay. It has been set up by its previous owner to run on a track powered DCC layout. It is equipped with an ESU v3.5 decoder, and wired for sound. It is my intention to have it converted to RC/battery operation incorporating the existing ESU v3.5 DCC card. A local installer I use has said this will be a fairly simple swap over of power method. I am having similar swaps to RC/battery operation of my existing DC operated stock, using the ESU v4 DCC cards with loco specific sounds loaded. Yes, I have finally bitten the bullet regards DCC, at least for 6 locos :D Naturally all these locos will need to be equipped with DCC compliant RX's and TX's to operate.

MY question - Can I test run this one loco on rollers using a regular DC power supply ? - In my case from a 10 amp Train Engineer 5470 combo' that can be set to either DC or PWM output, either 13v or 18v. I can wait, but I was just curious. If possible will the chuff work or remain silent without any command from a controller ? I know from my nascent 009 set up that operation of a DCC loco from a DC supply is highly undesirable, or is it the other way around :think: Max
 
yes, probably...
  1. the DCC decoder can be programmed to respond to DC, it's in CV29....
  2. in all cases when running a DCC decoder on "DC" make it non-pulsed DC, PWM is pulsed DC....

So, if it runs, then all is well, SCV29 set to "analog conversion" (reference NMRA DCC specification) and your "DC" is accepted by the decoder.

If it does not run at all or strangely, then one or both of the 2 criteria above is not met.

Simple and complete answer to your question.

Greg
 
I have had the other DCC Shay running around my line this afternoon on my train engineer. No problems whatsoever. Just SWMBO saying "it doesn't go very fast"
 
Greg Elmassian said:
yes, probably...
  1. the DCC decoder can be programmed to respond to DC, it's in CV29....
  2. in all cases when running a DCC decoder on "DC" make it non-pulsed DC, PWM is pulsed DC....

So, if it runs, then all is well, SCV29 set to "analog conversion" (reference NMRA DCC specification) and your "DC" is accepted by the decoder.

If it does not run at all or strangely, then one or both of the 2 criteria above is not met.

Simple and complete answer to your question.

Greg
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Of which regrettably I cannot make head nor tail of Greg. Staring with CV 29. Remember I have no means of accessing this, whatever it is. Max
 
maxi-model said:
Of which regrettably I cannot make head nor tail of Greg. Staring with CV 29. Remember I have no means of accessing this, whatever it is. Max
Click to expand...
Then, to start with, don't worry about CV29. Hopefully it's already set to a suitable value. Make sure the Train Engineer DC/PWM switch is set to DC and attempt to test run the loco.
If it doesn't move you'll most likely need access to a DCC control system and someone familiar with it.
 
Greg Elmassian said:
Max, then just read a bit further:
If it does not run at all or strangely, then one or both of the 2 criteria above is not met.

All the information possible to answer your question was provided.... You won't harm anything (or I would have warned you)..

Greg
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The problem is I do not understand the two criteria you have set Greg therefore, yes, only the last statement, in my case, could be valid.

Without any definitive statements either way I'll take it it's best left alone until my local installer gets back online. Max
 
Max, this is probably just going to be repeating what Greg and Neil have said... but it should be fine to test the loco on DC track power, PROVIDED that your Train Engineer is switched to the "linear" DC position rather than the PWM setting. DCC decoders don't like PWM pulsed DC power, but they are perfectly happy with simple DC. My own test bench rig has a little LGB 1-amp linear DC power pack as well as an input for my Massoth DCC, and a simple toggle switch to flick between one or the other as required. The 18 volt setting on the TE should be just fine, but feel free to try it first on the 13v setting first if you're more comfortable doing so.

You won't damage the decoder - the worst thing that will happen is that the loco simply won't move, and that should only occur if somebody has turned off the DC option on your decoder (by altering CVs), in which case it just won't do anything. Pretty much all decoders (well, all in my experience) are supplied with the DC option turned ON as a default, and there are really very few reasons or circumstances in which somebody would choose to turn that option off; the only one that really comes to mind is if somebody has fitted a separate after-market power buffer to the decoder.

My expectation would be that your loco will run just fine, probably with the running sounds (chuff etc), smoke and lights all working. What you won't have on DC is individual control over sound functions like whistle and bell. If it doesn't run at all, then no harm done - you would then just need to get somebody to change the CV value to re-enable the DC running.

Jon.
 
Thanks for your replies. So, so long as I set my TE controller's output to linear all should be fine to test run the loco. All being well my 20 amp Crest power supply should deliver suitably clean DC current to the TE. I should be able to hear the chuff and lights should be operable as will the smoke (I assume still set the smoke switch to DCC under the smoke box door to activate). Naturally all other triggered sound options will not activate. If it don't run, never mind it's the way one of the CV's has been set to exclude DC operation.

All operations on my line are now battery or live steam. I am running 100% dead rail now (nothing is stopping me reattaching the TE, but I do not intend to as a new track formation is going in that will cause a current polarity conflict. And I cannot be bothered with fitting another DPDT switch and track isolators. The TE/Crest is now retained only as a handy workbench/test line tool for testing motors and other assemblies. Really I have no need to run this loco, but curiosity...........I only asked as this is the only track powered loco I have brought in with a DCC decoder fitted, for 45 mm gauge use. It is handy that its decoder can be incorporated in its intended RC/battery operation guise. And that I had settled on the ESU card for installation in 6 other locos. Again thank you. Max
 
Not sure why setting the smoke switch to DCC would make it smoke on DC, maybe this is a typo on your part:

"I should be able to hear the chuff and lights should be operable as will the smoke (I assume still set the smoke switch to DCC under the smoke box door to activate)."

I would guess that setting the smoke to DCC would make it not run on DC.

Greg
 
Greg Elmassian said:
Not sure why setting the smoke switch to DCC would make it smoke on DC, maybe this is a typo on your part:

"I should be able to hear the chuff and lights should be operable as will the smoke (I assume still set the smoke switch to DCC under the smoke box door to activate)." and trying to make me look f

I would guess that setting the smoke to DCC would make it not run on DC.

Greg
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I was thinking of the later Bachmann products fitted with the PnP PCB and other switch gear on that board. They have that feature for smoke generator operation. The older models do not make the distinction, a simple on off. A simple oversight Greg, no need to make a big deal of it. Max
 
No big deal Max, just trying to answer questions and be helpful. Since you had a lot of trepidation to just try to power it, I wanted to make sure you did not have the wrong expectation of setting the smoke unit to operate from DCC when you are testing on DC.

People are indeed trying to be helpful.

Greg
 
maxi-model said:
I was thinking of the later Bachmann products fitted with the PnP PCB and other switch gear on that board. They have that feature for smoke generator operation. The older models do not make the distinction, a simple on off. A simple oversight Greg, no need to make a big deal of it. Max
Click to expand...

I'd probably be inclined to switch the smoke OFF for the first test, Max - then if everything else works as expected, turn the smoke switch back on and try it again.

Jon.
 
So, took a deep breath........It runs !........but the sound was very poor and the lights did not light. Didn't try the smoke. No worries, it will go to the "person who knows" for conversion to RC/battery operation. More importantly who has the kit to load ESU decoders with the stuff that makes them sing, and a few other things beside. As I mentioned, I do not need to run it and it came from a reliable source. So, time to be patient for an expert to work their magic and it can join the rest of operational the West Well roster. Max

And here it is resplendent in its new owner's designated logo and number. All courtesy of G Scale Graphics fine speedy services.

20210918_184800.jpg
 
I believe that is the earlier 36 ton shay, as opposed to the 38 ton (below):So there is a switch in this 2 truck shay for the smoke unit that has a position labelled DCC? (I went back to see what the loco is)

LS_38TonShay.jpg


Below is the 36 ton:
zo0r8lf2qrm51.jpg


But the "covers" over the gears are not silver or brass as in your picture.

It does look very nice!

Greg
 
No, most certainly a 38 ton with die cast trucks. It says so on the box and has the newer metal spring centred knuckles and not the old plastic with a straight plastic centering tang set below (look carefully at your pictures). I have fitted mine with slightly modded Kadee Climax items I had to hand to couple to Fn3 standard height couplers. I can also fit (as used by previous owner) cranked links for link/pin coupling, simple pull the pivot pin and switch the couplers. Bachmann as far as I am aware never fixed the coupler height issue on the two versions 2 truck or the 3 truck for Fn3 standards with their truck mounted couplers. Heisler and later Climax have them though (including an extra beam mounted knuckle in the muti height pocket one for the Climax).Two position on/off for the smoke. Are you getting fooled by the air tank that is absent from the stock picture that Bachmann use on their 38 ton parts page ? The tank's in the 38 ton's parts diagrams, as is the lack of alternate couplers for the different height standards. Possibly made a 38 ton version without the tank. The gear covers are black, it's the lighting. Max
 
One of the reasons that dcc engines run slow on DC is the DC speed parameter is set for slow. My decoders have 2 different CV's for max speed. (Zimo has CV 57 for max speed) as well as the standard CV5 per NMRA specs.
 
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