Loco Stopped. “Motor Over Peak Current”

[MtRR75]

BACKGROUND:
(1) Loco is a used BLI 2-8-2.  Converted to RailPro by Yankee Dabbler.
(2) Power is RailPro PWR-56.  Controller is HC-2.  Decoder is LM-3S – Hardwired.  Software is current for both.
(3) LM-3S has a “keep-alive” installed with it.

THE SET-UP:
(1) Recently installed Heavy Steam ULT.
(2) Also, changed the Bell file and the Chuff rate, changed the Brightness and Volume settings on some of the files
(3) Tested loco running and all LM Buttons – no problems.
(4) Cleaned wheels and Lubricated loco (Labelle).
(5) To work the lube into the joints, I ran the loco (and a consist of eleven 36 ft. boxcars) around a loop in my layout – at a modest speed (about 20-30 scale MPH).

WHAT HAPPENED
(1) After about 20-30 minutes, the loco suddenly stopped running – on a section of straight track.
(2) The “Info” screen gave me a “Motor Over Peak Current” message.
(3) The chuff sounds stopped, but the “Idle” sounds (from the Heavy Steam ULT file) continued to play.
(4) The headlight stayed on, and I could play other sounds (like Bell or Sanding)
(5) The HC-2 indicator symbol turned Red.
(6) But, the indicator on the PWR-56, remained green.
(7) However, “Motor Current” showed “0%”.
( Track Voltage registered at 13.9 V in the Info Screen, and 14.4 V on my digital on my voltmeter applied to the track.
(9) Several other locos were sitting on the track.  I tested a couple of them.  They ran fine.

THE AFTERMATH
(1) I turned the whole layout off and waited 2 days (my next chance to get back to the train room).
(2) When I turned the layout back on, nothing had changed from 2 days earlier – except that the “headlight” and “engine” buttons were now off.  But I could turn then on again.

Any ideas what is going on?

[G8B4Life]

There's a few possibilities:

(1) The motor is developing fault
(2) The motor has died
(3) The mechanism has seized/jammed preventing the motor from turning
(4) There is a short between the motor leads.

First thing I'd do take the shell off and see if you can freely turn the mechanism by hand ruling out (3). While the shell is off you can check the motor leads. If both of those are good you can try raising the motor full load current and seeing if it runs. Motors usually draw less power after running in but if a fault is developing it might start drawing more.

- Tim

[MtRR75]

Thanks for the ideas. I will report back once I get the time... and when I figure out how to get the shell off.

Doug

[carrson]

Hello...I had the same "motor over peak current " issue with an Athearn Loco...it would run for a bit then stop ... took it apart to finally discover that a commutator wire had separated from the com... not saying that is the issue with your loco just what happened to cause mine...

Larry 

[MtRR75]

There's a few possibilities:

(1) The motor is developing fault
(2) The motor has died
(3) The mechanism has seized/jammed preventing the motor from turning
(4) There is a short between the motor leads.

First thing I'd do take the shell off and see if you can freely turn the mechanism by hand ruling out (3). While the shell is off you can check the motor leads. If both of those are good you can try raising the motor full load current and seeing if it runs. Motors usually draw less power after running in but if a fault is developing it might start drawing more.

- Tim

As for (3) mechanism moves easily from motor all the way to the drive wheels.

As for (4) the resistance across the motor leads is about 5 Ohms.  Not sure what that means.  (I have limited electronics knowledge)

Doug

[G8B4Life]

As for (3) mechanism moves easily from motor all the way to the drive wheels.

That's a good start. At least the mechanism isn't stuffed.

As for (4) the resistance across the motor leads is about 5 Ohms.  Not sure what that means.  (I have limited electronics knowledge)

Neither do I, I don't know what the resistance should be. Apparently it's not so simple to measure the armature resistance of a permanent magnet DC motor so 5 ohms may be correct or it might be way off but I just measured a motor and got the same ball park figure.

Sorry, when I said short between the motor leads I was thinking damage to the insulation that was allowing a short.

Does it go straight to the motor overload warning as soon as the throttle is moved or does it take "giving it some juice"?

- Tim

[MtRR75]

Does it go straight to the motor overload warning as soon as the throttle is moved or does it take "giving it some juice"?

For locos that work....  I set the loco on dead track.  Then, I turn on the power.  If the room is quiet, I hear a faint click through the speaker less than one second after power up.  I am guessing that this is the LM turning on.

For this loco....  I set the loco on dead track.  Then I turn on the power.  I hear the LM click on, followed about a second later with a second click.  About a second after the second click, the triangle warning sign shows up on the LM-2 loco screen.  By the time that I punch the Info button the "Overload Warning" is waiting for me on the Info screen.  No time to power up.  NOTE:  See partial correction in next post.

Also, My brother-in-law knows lots more about motors and overloads than I do.  But he admits that he has never worked with motors this small.  However, he said that 5 Ohms sounded about right to him.

[MtRR75]

More Info.....

(1) While the shell was off and the loco was sitting on a table, I used the old “9-volt battery test” to check if the motor was working.  The motor and the gears ran in both directions.  I put the loco on dead track and repeated the test.  Same results.  So the motor is OK.

(2) Next, I turned the track on, then looked at the Info Screen on the HC-2.  Initially there were no error messages.  On the Info Screen, the Motor Current was zero, and the Voltage was 13.9 V.
Next, while I kept looking at the Info screen, I started turning the speed knob in on the HC-2.  Immediately, I got the “Motor Over Peak Current” message.  (The Motor Current remained at Zero, and the Voltage remained at13.9 V.)

Two corrections:
(1) The only “Click” I get is when the track is first powered up.  The second click that I heard earlier may have belonged to another loco that was sitting on the track
(2) This loco does NOT have a “keep alive” installed in it.

[G8B4Life]

So it seems that the motor's ok but do remember that a battery doesn't have an overcurrent setting so if the motor was previously drawing eg 300mA and it was now suddenly drawing eg 2A due to a fault the battery would still power it.

If the motor is actually good then that just leaves the LM. As it goes into overcurrent immediately as the throttle is turned there's only a couple of things I can think of.

• The Motor Max Current setting in the LM has been messed up
• There's an internal fault in the LM

If you haven't done so check what the motor max current is set to in the LM, obviously it shouldn't happen but maybe there was a glitch and it got set to zero or some really low figure. See if increasing helps.

If you still get nothing at this stage I'd try swapping out the LM for another one and seeing if the problem persists.

I'm also not sure about these "clicks" you hear, I'm not sure that you should hear clicks or not. I can't remember hearing them but then it's been a very long time since I powered on an LM.

- Tim

[faithie999]

if you have a multimeter, re-do the "battery test" with the meter set to the Amp setting and the meter leads in series between one of the battery terminals and the motor.  then you'll have to correct the amp reading for the fact you're using 9volts instead of 14 volts--multiply the reading you get by 9/14.

I assume you've been unplugging the LM for the battery test to prevent possible damage to the LM.

[MtRR75]

Still More Info:

(1) The Motor Max Current is set to 220 mA, which is the same that it was before this trouble started.

(2) I tried turning the speed knob VERY slowly, to see if the current on the Info screen gave any indication before the “Motor Overload” error message froze the screen.  Out of about half a dozen tries, I got ONE piece of data.  One time, the Motor Current indicator flashed for less than a second before the “Motor Overload” message took over.  I am 90% sure that I saw the number “60” or “69”.  And I also saw the vertical bar current indicator flash for less than a second.  As best I could tell, it was between 60% and 80%.  Remember that the speed knob was turned a tiny amount.

(3) As for swapping out LMs, I can’t do that.  Remember that the LMs were installed by Yankee Dabbler.  They are hard-wired – no plug.  And I don’t have the skills to solder such small wires.

(4) What I can do is erase the Heavy Steam ULT file on this LM and recopy it from the HC-2.  The rest of the files on this LM are all performing fine.  And the copy of the Heavy Steam ULT file on the HC-1 has been successfully copied to, and run on, four other locomotives.  So, I see no need to recopy the file from the internet to the HC-2.  I will let you know what happens.

[G8B4Life]

(1) The Motor Max Current is set to 220 mA, which is the same that it was before this trouble started.

Yes, but the motor may be drawing more than that if it's developed a fault.

(2) I tried turning the speed knob VERY slowly, to see if the current on the Info screen gave any indication before the “Motor Overload” error message froze the screen.  Out of about half a dozen tries, I got ONE piece of data.  One time, the Motor Current indicator flashed for less than a second before the “Motor Overload” message took over.  I am 90% sure that I saw the number “60” or “69”.  And I also saw the vertical bar current indicator flash for less than a second.  As best I could tell, it was between 60% and 80%.  Remember that the speed knob was turned a tiny amount.

Going straight to overload does kinda indicate that there is a path of low resistance from one motor output to the other motor output external to the motor, or there is a fault with the motor that is causing it to draw much more current than before, triggering the LM's overload because it's expecting no more than 220mA.

(3) As for swapping out LMs, I can’t do that.  Remember that the LMs were installed by Yankee Dabbler.  They are hard-wired – no plug.  And I don’t have the skills to solder such small wires.

Are you saying that YD removed the 9 (and 6) pin sockets from the LM and soldered directly to the LM's board? If so I'd be looking here for anything awry too.

(4) What I can do is erase the Heavy Steam ULT file on this LM and recopy it from the HC-2.  The rest of the files on this LM are all performing fine.  And the copy of the Heavy Steam ULT file on the HC-1 has been successfully copied to, and run on, four other locomotives.  So, I see no need to recopy the file from the internet to the HC-2.  I will let you know what happens.

I'd be very surprised if the sound file had anything to do with it but anything is worth trying.

- Tim

[SWA737]

I just had a similar problem on a recent Railpro conversion. This is my 43rd converted engine. This is the first time I messed up setting up the controller. I set it on the track and begin to run it prior to doing the “Motor full load current. Just completely forgot to do it first. It ran for just a couple of seconds and then that was it. I then tried to go back and do the test but when I did, it said test failed and the little caution yellow triangle pops up saying “ Motor over peak current”. Did I possibly burn the motor up? The lights and sound work well.

[G8B4Life]

SWA737,

I wouldn't think you've killed the motor, or damaged the LM either. I've run LM's before in my LM tester without setting the Motor Full Load Current without issue that I can remember, though it was all non loaded stuff (ie just a bare motor) just to check the motor outputs worked.

A couple of things you could try are:

• Removing the LM from the HC and then redetecting it. It should indicate that the Motor Full Load Current test hasn't been done and the test may work this time.
• Manually setting the Motor Full Load Current to a higher value and then trying the automatic test again.

If neither of those work it might be time to find out what the motor actually draws.

- Tim

[ON28]

Can the LM be used in a loco without setting Max Current at all?