gmpullmanBroadway Limited Paragon 3 decoders have motor protection built in, customizable using CVs, however, when they install motors that are too close to that limit it results in stuttering and shutdowns that become very annoying pretty quickly.
ESU decoders use CV247 as one of the automatic-uncoupling functions. So we need to look elsewhere. In the latest manual I have for LokPilot v.5, the "Motor Overload Protection" is bit 5 of CV124, the "Extended Configuration #2) which means that you'd increment the value by 32 if the protection is OFF and you want it ON, or decrement the value by 32 if... well, suppose you wanted to stall-test your motor and didn't want it to automatically cut off.
This is on p.81 of the version 7 edition of the LokPilot manual from ESU (dated May 2021), available via this link.. You can select both the LokPilot and LokSound manuals from this page, and I presume as later versions become available they will become listed here.
Be advised that I had to scroll the license agreement down to the bottom for the first manual to be able to click the actual 'download' button.
Lastspikemike All new ESU decoders are equipped with output current overload protection, motor, lights everything.
All new ESU decoders are equipped with output current overload protection, motor, lights everything.
Alton Junction
(1) I can't see the pictures he posted of the damaged decoder. Has anyone actually identified the section that 'melted'?
(2) If I were the one 'troubleshooting', right after I measured the stall current, I would let the motor slowly turn through a few rotations and see whether there was a bad commutator or fault in the winding insulation that was causing high current in only a particular position. It might at some point be valuable to look at the armature to see if there are any signs of shorting or burning -- this is something of additional concern if he has a coreless motor.
It is my considered opinion that Ed's advice in the first reply in this thread and in the post concerning the CV adjusting overcurrent protection have given the OP as much assistance as this thread needs, or is likely to, supply... and the OP needs to find out what is cooking decoders before putting in a different manufacturer's product.
looks like some decoders montor BEMF and recognize when the motor has stopped turning and may shut down or at least cycle power.
they don't explicitly monitor current like boosters, circuit breakers or auto-reversers, so are still prone to damage if the motor's normal operating current exceeds the rating of the decoder.
LastspikemikeI'd buy and install an ESU decoder. https://www.esu.eu/en/news/read-news-entry/article/lokprogrammer-5012-verfuegbar/3/
https://www.esu.eu/en/news/read-news-entry/article/lokprogrammer-5012-verfuegbar/3/
your link is not to a decoder
greg - Philadelphia & Reading / Reading
Interesting, what kind of lawyers? Studyed real estate law some for writing and reading contracts and dealing with cities along with tenent landlord law, now you can proubly guess what I used to do.
LastspikemikeThe stuff you are all complaining about we learn at law school...
Mike, it should come as no surprise that you are not the only lawyer in this group.
I am not going to "out" any of the others. I correspond off the forums with many of the people in here, and have developed several strong friendships. The other people in here that share your profession are enjoyable, non-argumentative, and even helpful when they know the answer.
What you are, is the only person in here who behaves like you do. You argue so many sides of every topic, and you rarely have any understanding of what you are saying. You disagree with long-established truths of model trains. You ignore knowledgeable people that know the real answers. Then in the end, you just copy-and-paste something that someone else said and act as though you have some sort of deep understanding.
You especially love to do this in threads posted by new participants. This just gives them a sour experience and they do not come back. I personally know of one great person you ran off with your act. That was a tragedy.
I assume you do this to be destructive and chaotic.
How come all the other lawyers in here never say things like this? How come they can just talk about our model trains, share pictures, share experiences, and learn from one another?
What are you trying to do in here?
SPIKE went another thread.
And I know by typing this I gave you some of the attention you so desperately crave.
-Kevin
Living the dream.
wrench567 I believe the OP has left the building.
Once again. I wonder if some of these posters get flustered at all the extraneous responses that really do not help them?
If you are still out there, please read the posts that are helpful (ie: is the decoder rated for the locomotive, is the loco running properly). Some of the folks here really want to help you.
rrebellThat one is easy, a reseting thremal breaker which do exist, but do they in the size ect. thjat we need.
Broadway Limited Paragon 3 decoders have motor protection built in, customizable using CVs, however, when they install motors that are too close to that limit it results in stuttering and shutdowns that become very annoying pretty quickly.
CV247
This value sets the length of time in seconds that a motor over current condition is allowed before removing motor power. This condition exists when the motor is supposed to be moving, but is not. A value too small may cause the over current circuit protect to falsely activate, while too long may cause damage to the motor or decoder if the motor is jammed from moving and motor power is applied. Once the circuit is activated, simple set your throttle to zero momentarily, than throttle up (assuming the problem was removed) and the motor will receive power again. If backEMF (CV10) is disabled, the over current is also disabled. Setting the value to 255 disables this function.
Good Luck, Ed
gregc Lastspikemike It should be simple enough to build a decoder that won't accept more than x amps. you say it's simple. what do you think it would take?
Lastspikemike It should be simple enough to build a decoder that won't accept more than x amps.
you say it's simple. what do you think it would take?
richhotrainIf there has been a pursuit of red herrings in this thread, it has been the continuing attempt to redefine stall current.
Sometimes I wish there was a "LIKE" option to thread replies. Rich has made an excellent summary here. I like it.
Regards, Ed
Lastspikemike The OP made no mention of his locomotive stalling anyway. I think this speculation involves the pursuit of red herrings.
The OP made no mention of his locomotive stalling anyway. I think this speculation involves the pursuit of red herrings.
elmertc19 I bought it new off E-bay a little more than a year ago and in that time, it has melted two decoders. Is there something I should check for or do to prevent this from happening again?
I bought it new off E-bay a little more than a year ago and in that time, it has melted two decoders.
Is there something I should check for or do to prevent this from happening again?
True, the OP made no mention of his locomotive stalling. What he did mention was that the loco has melted (fried) two decoders. In trying to determine if excess current is being drawn by the motor, you measure stall current. If the OP had mentioned that his loco was stalling, you woudn't measure stall current. Two different things.
If there has been a pursuit of red herrings in this thread, it has been the continuing attempt to redefine stall current.
Lastspikemikebemf stops and heat resistance starts.
there is always heat generated by a motor due to a current flowing thru the wires. the difference between that power when moving and stopped is that the bemf reduces the effective voltage across the windings. the current equals the applied voltage - the bemf due to the armatures turning in a magnetic field divided by the wire resistance which is a constant.
so the maximum current is when the bemf is zero
the other aspect of a turning armature is that it moves the air which helps dissapate the heat.
LastspikemikeA motor or engine stalls when the load exceeds the torque the motor or engine can exert.
on most model locomotives, the motor has more torque than traction and when the load exceeds the traction the wheels simply spin. (see my original post). the traction is typically ~25% of the weight on the drivers.
the wheels would slip if you simply blocked a model locomotive from moving. you would have to press down on the locomotive to stop the wheel from spinning and stall the motor, as you said
LastspikemikeThe OP made no mention of his locomotive stalling anyway.
the OP said his decoder melted. the decoder needs to have a sufficient current rating. stall current is typically the value the decoder should be rated at or exceed. it shouldn't "melt" if is does, even when stalled
LastspikemikeLocking the armature and applying voltage may not yield the stall current.
may not but close enough. why not make some measurements yourself
In my experience, 'locked-rotor' means keeping the armature from rotating in response to magnetic torque -- it doesn't matter whether instantaneously or for some more extended period of time. There is something of a distinction without a difference in trying to make 'instantaneous' and 'locked' mean two different things in this context.
On the other hand, there may be a difference between momentarily stalling a turning motor and applying voltage to one that is not turning. In the current (no pun intended) context, we are applying external force to a turning motor that 'causes it to stop turning' and reading the current it draws at that moment. That is the point at which stall torque can be measured, or stall current measured. I would argue that it is the way it ought to be measured experimentally in the current situation, whether by bringing a locomotive to a halt or pinching the shaft of a motor.
In my opinion the IMPORTANT issue for the OP is that the amount of current that makes a decoder 'melt' is larger, perhaps wildly larger than the 'stall current' observed from stopping shaft rotation. The procedure we were recommending was that the motor stall/locked/whatever current be MEASURED as an early step in diagnostics, to confirm there isn't some issue that might cause high current -- to me, this problem sounds like there is some kind of induced short, probably through the motor somewhere, that passes enough current to roast part of the decoder but not show obvious, visible damage on some other part of the locomotive.
A surprising thing about the story 'so far' is that the OP reports no overcurrent protection 'firing' to keep the decoders from melting. This would tell me there is a high current from 'whatever is melting' but it isn't high enough to trip protection -- someone 'in the know' might advise him to install one of the fast-acting adjustable breakers in his power supply system...
Lastspikemikehe number is the current draw just as the armature stalls.
why is that current not the same a moment after it stalls, or 10 sec later? what changes?
Lastspikemike My only point about stall current load is that it occurs when motor torque equals load. While it is correct that you will find this number if you momentarily lock the armature that is not the definition. The number is the current draw just as the armature stalls.
My only point about stall current load is that it occurs when motor torque equals load. While it is correct that you will find this number if you momentarily lock the armature that is not the definition. The number is the current draw just as the armature stalls.
But, you still disagree with Ed and dcciwiki that it is the definition of stall current. So, how do you define stall current?
LokProgrammer is not a decoder
LastspikemikeMy only point about stall current load is that it occurs when motor torque equals load.
again, max current occurs at max voltage with the armature not moving. this is when there is no BEMF and the current is limited by the wire resistance in the armature, Ohm's law. it's that simple
LastspikemikeI'd buy and install an ESU decoder.
I had a run of Loksound Selects and Select Micros that were dead on arrival. ESU replaced two of them, the other three were over the one year warranty period and Matt Herman would not honor the warranty.
I've since installed over a dozen Loksound V5s that seem to be OK... so far.
Hint: Test your decoders as soon as you buy them!
I've had a few of the old DH-121, 123 and one or two of the later DH-126 decoders "melt". You can see the hot-spot where it burns right through the blue shrink wrap. I may have tossed a few in my decoder bin. I'll have to look later but I think I finally got rid of them.
Usually, for me anyway, when I blow a lighting output you don't see any physical damage to the decoder but the function is open on the minus side. I've had some Soundtraxx decoders that when a function output "shorts" it is always closed so the light remains on no matter what command is given.
On some where the blue wire 12V gets shorted it will simply go dead but the motor control will still work (OK for a B unit).
I believe the OP has left the building.
One other thing no one has considered is the fact we don't know what is burnt on said decoder. It could very well be the lighting circuit. I believe the spec calls for UP TO 100 milliamps. I had some 14 volt bulbs that drew more than that.
I hope this is clear.
Pete.
Water Level RouteAnd yes, I'm saying what I'm saying and also what I'm meaning. Not what you say i said but didn't mean even if I said it the way I said it, but meant what you meant but didn't say, even though you say you said it. Oh brother.
This is LSAT 101.
If you can't dazzle 'em with brilliance —
Will we ever hear from the OP again?
Cheers, Ed
Wow. And to think I saw all the replies to this thread after not having read it for several days, I assumed progress had been made on helping the OP. What a mess.
And yes, I'm saying what I'm saying and also what I'm meaning. Not what you say i said but didn't mean even if I said it the way I said it, but meant what you meant but didn't say, even though you say you said it. Oh brother.
The DCC Wiki post is perfectly clear.
Mike
LastspikemikeIt should be simple enough to build a decoder that won't accept more than x amps.
SeeYou190You know. LSM can attack me all he needs to. I openly admit I have very little idea of most of what you guys discuss. I am only good at three, maybe four, parts of model railroading. I have almost no knowledge of real trains at all. I come to these threads to learn. LSM ruins a lot of this by "spiking" threads like he has done with this one. I find that very irritating.
I would urge you to have some wine, relax, and try not to let that individual bother you.
Lancaster County, Pa., is maybe 25 miles from here. The Amish have a way of dealing with people who bother them. It is called "shunning". One definition is:
"persistently avoid, ignore, or reject (someone or something) through antipathy or caution."
richhotrainGeez, and all that Ed was trying to do was to answer a simple question. What a mess trying to sort through the above reply to Ed’s answer.
After years on this forum I can cofirm that Ed's answers can always be "taken to the bank" with complete confidence. He is a deep fact driven source of accurate knowledge, experience, wisdom, and support.
The only times I know of where Mike is right is when he copies-and-pastes one of my answers as his own.
What a mess.
richhotrainlastspikemike vs. gmpullman. Reminds me of Ghostbusters. When you need an answer, who you gonna call? I’ll cast my lot with Ed any day.
You know. LSM can attack me all he needs to. I openly admit I have very little idea of most of what you guys discuss. I am only good at three, maybe four, parts of model railroading. I have almost no knowledge of real trains at all.
I come to these threads to learn. LSM ruins a lot of this by "spiking" threads like he has done with this one. I find that very irritating.
His knowledge level is even lower than mine, but he tries to answer questions where he lacks any sort of the depth of information to be helpful.
LSM has run off some of the best providers of information we had in our ranks, and diminished the participation of others with his act.
Now, to attack the "Grand Poo-Bah" (I hope I got that right) of our group is completely unacceptable.
Where is the line drawn?
You should jump right on that and make so much money that no one can ever doubt you again.
LastspikemikeExactly. But in our real model world only a few things can result in the armature not moving which is the effective maximum current the decoder needs to handle.
i hesitated to say stall current because it's hard for me to imagine how to prevent the wheels of diesel locomtive from spinning.
but i can imagine the side rods of a steam locomotive getting caught on something and locking up the wheels
LastspikemikeFor a DCC locomotive the maximum current draw will be limited to the traction available from the drive wheels which may or may not coincide with maximum applied voltage
the maximum current is unrelated to traction (which is related to weight).
once again, maximum current occurs at max voltage with zero BEMF, in other words with the armature not moving.
LastspikemikeI suspect the maximum amperage capacity of a decoder is designed with the normal maximum power capability of the locomotives it is intended for.
i doubt many decoders are designed for specific locomotives. locomotive manuacturers select a decoder from decoder manufacturers that meets/exceeds their requirements.
modelers must select decoders that meet/exceed the stall current of the locomotives they are installing the decoder in, as pointed out repeatedly
LastspikemikeStall current will be the same whether you measure it just before the drive wheels begin to spin or after you briefly stop the wheels from spinning.
yes. what is your point?
the decoder isn't damaged by the current momentarily exceeding it's rating. it's damaged by the heat build up due to sustained excessive current.
it's conceivable that a decoder would be damaged at less than stall current over a long period of time with the armature not moving and not moving any air allowing cooling.
Lastspikemike gmpullman Lastspikemike Isn'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 Sure, but when is that ever going to happen? Actually, the link you posted is wrong grammatically. I know what they mean and they do not mean the armature is locked. Nor do they mean the armature is prevented from spinning even though they say that they don't mean that. They mean when the armature isn't spinning at maximum applied voltage which is not what they wrote. They mean what I said, not what you say they meant. This happens frequently on this board and in the hobby. Stuff is worded imprecisely and then misunderstood. Maximum current draw when the locomotive stalls by say hitting a track pin or other obstacle will be just before the wheels spin at whatever the applied voltage happens to be. The armature isn't ever going to lock.
gmpullman Lastspikemike Isn'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
Lastspikemike Isn'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.
Sure, but when is that ever going to happen? Actually, the link you posted is wrong grammatically. I know what they mean and they do not mean the armature is locked. Nor do they mean the armature is prevented from spinning even though they say that they don't mean that. They mean when the armature isn't spinning at maximum applied voltage which is not what they wrote.
They mean what I said, not what you say they meant. This happens frequently on this board and in the hobby. Stuff is worded imprecisely and then misunderstood.
Maximum current draw when the locomotive stalls by say hitting a track pin or other obstacle will be just before the wheels spin at whatever the applied voltage happens to be. The armature isn't ever going to lock.
Geez, and all that Ed was trying to do was to answer a simple question. What a mess trying to sort through the above reply to Ed’s answer.
Lastspikemike I know what they mean and they do not mean the armature is locked.
LastspikemikeNor do they mean the armature is prevented from spinning even though they say that they don't mean that.
Lastspikemike They mean when the armature isn't spinning at maximum applied voltage which is not what they wrote. They mean what I said, not what you say they meant.
Lastspikemike This happens frequently on this board and in the hobby. Stuff is worded imprecisely and then misunderstood.
The current that an electrical motor draws when its shaft if prevented from moving. This is typically the highest current a motor will draw. The stall current of a locomotive should be less than the peak current capacity of the decoder that is fitted.
LastspikemikeI know what they mean and they do not mean the armature is locked. Nor do they mean the armature is prevented from spinning even though they say that they don't mean that. They mean when the armature isn't spinning at maximum applied voltage which is not what they wrote.
the maximum current drawn by a motor is at max voltage with the armature not moving -- regardless of the wording
Dear Alyth,
LastspikemikeSure, but when is that ever going to happen?
Traction tires, added weight, low torque motor, binding running gear.
LastspikemikeThey mean what I said, not what you say they meant.
Sounds like a word salad to me. You have life-long training in this department.
Are you saying "stall" current is measured without the motor being stalled? I'll quote our late forum friend, Randy Rinker in regards to this.
rrinker Step 1 - go to Harbor Freight and get the $5 or less multimeter. Last flyer they had a coupon for a free one, but I forgot to go get another. Step 2 - grab your old DC power pack, and a spare section of track. Plug the multimeter leads in for the 10 amp range. Connect one rail to the variable DC of the power pack. Connect the other rail to one multimeter lead (clip leads work great for this). Connect the other multimeter lead to the other variabel DC power pack terminal. Step 3 - remove shell of loco and set on the rails Step 4 - don;t forget to turn on the multimeter Step 5 - hold the loco so it just spinds, crank up the DC power pack to full throttle. Note the approximate reading of the meter (it will be varying a lot I'm sure). Step 6 - the hard part - while looking at the multimeter, grab one of the flywheels to stall the motor and note the reading. Do not hold it long, just to see the number. Step 7 - shut off the power pack. If the meter reading in Step 6 was 1.0 or less, this is definitely not one of the problem motors and a normal HO decoder can be used just fine. Up to about 1.3 amps - check the decoder you plan to use for the actual steady and peak currents it can handle, but HO is 1-1.3 amps usually. If you have one of the ones with the heavy current motor, it will be quite high 3-4 amps at least. Those will need new motors. Randy
Step 2 - grab your old DC power pack, and a spare section of track. Plug the multimeter leads in for the 10 amp range. Connect one rail to the variable DC of the power pack. Connect the other rail to one multimeter lead (clip leads work great for this). Connect the other multimeter lead to the other variabel DC power pack terminal.
Step 3 - remove shell of loco and set on the rails
Step 4 - don;t forget to turn on the multimeter
Step 5 - hold the loco so it just spinds, crank up the DC power pack to full throttle. Note the approximate reading of the meter (it will be varying a lot I'm sure).
Step 6 - the hard part - while looking at the multimeter, grab one of the flywheels to stall the motor and note the reading. Do not hold it long, just to see the number.
Step 7 - shut off the power pack. If the meter reading in Step 6 was 1.0 or less, this is definitely not one of the problem motors and a normal HO decoder can be used just fine. Up to about 1.3 amps - check the decoder you plan to use for the actual steady and peak currents it can handle, but HO is 1-1.3 amps usually. If you have one of the ones with the heavy current motor, it will be quite high 3-4 amps at least. Those will need new motors.
Randy
You can spell-check and analyze the grammar all you want, stall current is still STALL current.
LastspikemikeThe armature isn't ever going to lock.
Presuming the motor will never be locked (or stalled) is a gamble the owner will have to assume. I've had little pieces of ballast get picked up in the gearing. A new Broadway Limited SD9 loco I have had a small plastic chip in the worm gear housing, It would "lock" the motor, side rods bind.
Thanks for your valuable insight. I'll keep your advice in mind. In the meantime I will continue to measure stall current, especially with some of the open-frame motors I still have on brass engines, using the procedure Randy outlines above.
IMG_6621_fix (2016_08_17 08_08_12 UTC) by Edmund, on Flickr
There have been high-current motors installed in commercial locomotives, most recently in the Broadway Limited P5a and the Rapido RS-11s that have caused decoder failures. Some years ago there was a run of Life-Like PAs that all had high current motors.
Unless you test these to weed them out you WILL have burned or failed decoders.
THIS is from the manufacturer of the OP's decoder.
https://www.digitrax.com/tsd/KB466/what-is-stall-current/
To test N scale, use 10 volts.To test HO scale, use 12 volts.To test G scale, use 18 volts.While holding the motor shaft or the locomotive so that the wheels don't turn, quickly turn the voltage up to the specified voltage and read the Amp meter.
(my underscore)
Their grammar and spelling is superb.
Better safe than sorry, Ed
How things change. I remember reading on these pages years ago, probably in this very forum, that there was no consensus about exactly what was meant by "DCC Ready.". Most of the engines I've purchased with that label had no plug for a decoder, and required a hard-wired job. At first, I bought non-sound decoders with just wires, no plugs, and just wired them in.
I bought one of these DCC Ready locomotives from my LHS. The owner took the engine apart for me and showed me what I had to do before installing a decoder. I think it was something with insulating the headlight bracket. I did that and never had a problem.
As I recall, it would only be a problem if a particular derailment caused an inappropriate current to flow through the locomotive.
DCC Ready may mean nothing.
It takes an iron man to play with a toy iron horse.