LastspikemikeIsn't maximum current draw just as the drive wheels lose grip?
Stall current is measured at operating voltage with the armature locked:
https://dccwiki.com/Stall_Current#:~:text=The%20stall%20current%20should%20be,the%20decoder%20that%20is%20fitted.
I had a few early Life-Like PAs that had motors that would normally run close to 1 amp but when stalled the current would jump to 3 to 4.5 amps. Life-Like chose motors with the wrong specs.
Cheers, Ed
I have a couple Kato dash 9's and I use the DH165IP. I have no problems, not that this answers the OP's question, just saying.
The OP's pictures don't work for me, but I agree with others, there's a installation problem, maybe a direct short, and checking the stall current.
I wonder if this loco was really "new" ?
Mike.
My You Tube
gregcsure
—enough
Regards, Ed
I have one Kato locomotive that is "DCC ready". It is absolutely not a "Dash-9" anything.
It does not have an NMRA 8 pin plug. I think the Kato term "DCC ready" (in this instance) just meant the motor was isolated from the frame and there was a slot machined into the frame halves for space to mount a decoder.
Kato DC locomotives were a challange to convert to DCC because the motor was sandwiched in between two frame halves. These frame halves were both part of the electrical circuit to the motor. Isolating motors from these frames was very difficult.
Since this is just one locomotive, I have no way of knowing of this is typical of the majority of Kato models or not.
-Kevin
Living the dream.
Says he runs them all the time and that they melted. Also says nothing about factory installed DCC ready or what that even means as many manufactures have in the past said that only to find it not to be true.
Hello All,
elmertc19I have a Kato DCC ready...
The term "DCC ready" presumes that there is an NMRA 8-pin plug on the DC OEM PCB with a dummy plug and the motor is electrically isolated.
In theory...
To convert to DCC, the dummy plug is removed and the 8-pin to 9-pin DigiTrax wiring harness is installed.
Then the 9-pin decoder is plugged into the wiring harness.
"I don't mean to be facetious or didactic, but..." Woody Allen; Broadway Danny Rose, 1984.
How do you know the decoders are fried?
elmertc19...that I use pretty reguarly (sic).
How often do you run this unit?
Does it fry the decoder immediately upon power being applied- -booster turned on or commands sent?
Are you able to run this unit- -and for how long- -before it fries the decoder?
Is there physical damage to the decoder(s) that leads you to believe failure?
Thank you in advance for keeping us informed.
Hope this helps.
"Uhh...I didn’t know it was 'impossible' I just made it work...sorry"
Elmerc19,
We can't see your embedded pictures so we don't know which version of the DH-126 you are using and what the decoder looked like after it melted. I would think that is a 8 pin install since the that is what is specified in the Digitrax decoder selection tool.
Before each decoder melted, did you get a chance to check if the decoder became hot on a regular basis after use? If it gets hot after each use, then the suggestions about motor amperage are most like the main issue. If it does not get hot after each use, then I would suspect some type of short.
Scott Sonntag
gmpullman gregc (block the loco from moving allowing the wheels to spin)
gregc (block the loco from moving allowing the wheels to spin)
greg - Philadelphia & Reading / Reading
Well do remember the factory install dcc of Kato's sd80 Mac. That little tab that fired and shorted many decoders. Could this be a similar issue. A small factory created short somewhere? Ab bad factory wiring isn't out of the questionshane
A pessimist sees a dark tunnel
An optimist sees the light at the end of the tunnel
A realist sees a frieght train
An engineer sees three idiots standing on the tracks stairing blankly in space
I agree about the amps, that's what I would check first. There is no mention of short circuits, so it's unlikely to be the problem. I have installed dozens of Digitrax decoders, and only one has failed, by my own fault.
What I find intriguing is the fact that the loco is described as "DCC ready". Installation should be straigthforward and pretty much any decoder should meet the amp draw. What type of Digitrax decoder did you use? Was the engine operating normally in DC mode?
Simon
Sounds like someone did not do a proper conversion to DCC. I bought a Kato NW2 off e-bay with DCC and even though I have not had a proublem yet, if they did not do the conversion properly and it derails it will need a new dercoder.
gregc(block the loco from moving allowing the wheels to spin)
Stall current is measured by blocking the locomotive and not allowing the wheels to spin.
https://www.youtube.com/watch?v=7KbEVKZ2JhA
Good Luck, Ed
have you measured the max current drawn by the motor? (block the loco from moving allowing the wheels to spin)
is the decoder rated for at least that much current?
Are they 8 pin plugs? I have seen some 8 pin plugs that actually went through the female plug and contacted the metal frame below it.
Is it pulling heavy loads constantly? Any derailments?
Service and lube the locomotive before installing another decoder.
To tell you the truth, I have not had good experiences with Digitrax decoders. I had one smoke on a program track once.
Pete.
Hello,
It sounds like what you are encountering is too high of a current draw than the decoder can handle.
Do you have a way to bypass the decoder (dummy plug) or temporarily remove the decoder and use an ammeter to measure just how much current the motor is drawing. You should also measure the stall current.
Some of the earlier decoders required more air space around them, too. If your engine is drawing close to 1 amp and the decoder is mounted close to the motor there may be too much residual heat that may not be able to dissipate.
Look for any binding in the drive train, be sure lubricants are not too gummy. Apply a tiny drop of fine oil to the motor bearings.
If none of this helps you might resort to looking for a decoder with a slightly higher current rating, but for a Kato loco the current draw should certainly be more in the 400-500 milliamp range, well below the max for a DH126.
Lastly, it may be possible the motor is simply worn out, or at least the brushes are.
Good morning everyone,
I have a Kato DCC ready "Dash 9" locomotive that I use pretty reguarly. I bought it new off E-bay a little more than a year ago and in that time, it has melted two decoders. They've both been Digitrax. I've tried searching for answers, but haven't really found too much.
Is there something I should check for or do to prevent this from happening again? Attached are pictures of the decoder for that its worth. You can some marks on one of the pins which I believe connects to the red wire on the harness.
Thanks in advance.