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Discussion Starter · #1 ·
I set up a LGB Christmas Stainz engine with 2 passenger cars on an outdoor track for the Christmas holiday.
Last season, I burned out 2 brand new Christmas Stainz engines because a wheel of the engine came off the track
but not the connectors. This caused the wheels to spin and burn out the 2 engines. Is there something I can do about
this other than not run the train unsupervised? Would think there would be a circuit breaker that would turn off the motor when
it overheats. My Bridgewerks Magnum SR 15 has a circuit breaker that protects the unit. Shouldn't the engine have one too?
 

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I'm not quite sure I exactly understand you.

You say a wheel of the engine came off the track (I assume this means derailed) but not the connectors. What connectors? Do you mean the loco derailed, but the wheels kept spinning...

Interesting, in that if the wheels were spinning, you would think that the fact they are spinning would mean the motors were ok, and not heavily loaded....

Sort of does not make sense the motor would burn out... did the motor itself burn out, or were the gears damaged?

Again, the fact that the wheels were spinning would indicate that the motor load was not at maximum, and thus would not overheat.

Yes, you 15 amp supply has a breaker to protect itself. LGB is usually bulletproof and they don't have breakers, some of the other G scale locos do, but again, it does not seem you have an overload condition (over current, the only thing the breaker can react to).

Can you clarify / answer any of the items above?

Greg
 

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Discussion Starter · #4 ·
I'm not quite sure I exactly understand you.

You say a wheel of the engine came off the track (I assume this means derailed) but not the connectors. What connectors? Do you mean the loco derailed, but the wheels kept spinning...

Interesting, in that if the wheels were spinning, you would think that the fact they are spinning would mean the motors were ok, and not heavily loaded....

Sort of does not make sense the motor would burn out... did the motor itself burn out, or were the gears damaged?

Again, the fact that the wheels were spinning would indicate that the motor load was not at maximum, and thus would not overheat.

Yes, you 15 amp supply has a breaker to protect itself. LGB is usually bulletproof and they don't have breakers, some of the other G scale locos do, but again, it does not seem you have an overload condition (over current, the only thing the breaker can react to).

Can you clarify / answer any of the items above?

Greg
Hello Greg,

When I say connectors, I mean the sliding pickups as another post clarified. You are correct in that the train derailed but the wheels continued to spin.
I had 2 brand new LGB Christmas Stainz engines ruined for this same issue. I had one repaired and the parts replaced were as follows:
short shaft motor, wheelset for LGB Stainz, Carbon brushes 14 mm, 4-pack, power pickup shoes, 2-pack and traction tire.

There was a strong burnt smell and the wheels were locked in place when I discovered each engine. My track is an oval track on plywood with the
straight runs 10 feet. With the sliding pickups still drawing power and the wheels spinning, the train was only slightly derailed probably caused by
some slight exterior issue. Am afraid to run the engine unsupervised for fear of ruining another engine.
Any help would be appreciated.
 

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When a train derails and the 'slider' is picking up power and a short is happening, the springs heat up and melt into the plastic. Not enough power is drawn to trip a breaker on a 15 amp DC supply. What I do not under stand is the engine with a bad motor, wheels, brushes being bad. I have repaired well over 100 engines and have never seen this much damage in one engine. So, does the bridge werks model output 38 volts? I have seen this occur twice. Once from a bad LM317 in the bridgewerks. Other time was the front slider was at max which gives over 33 volts to the track on some models, way to high for large scale trains.
 

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Discussion Starter · #6 ·
When a train derails and the 'slider' is picking up power and a short is happening, the springs heat up and melt into the plastic. Not enough power is drawn to trip a breaker on a 15 amp DC supply. What I do not under stand is the engine with a bad motor, wheels, brushes being bad. I have repaired well over 100 engines and have never seen this much damage in one engine. So, does the bridge werks model output 38 volts? I have seen this occur twice. Once from a bad LM317 in the bridgewerks. Other time was the front slider was at max which gives over 33 volts to the track on some models, way to high for large scale trains.
Hello Dan,
Thanks for your help. I use a Bridgewerks Magnum 15-SR, 15 Amp Transformer, 1 track remote ready. I have attached the specifications supplied by Onlytrains.com where
I purchased this transformer last year. Also attached is the invoice from All About LGB where I had the engine repaired. It lists the parts replaced . Didn't understand the
wheelset being replaced as they were not damaged and they cost more than a new motor but lacked the knowledge or experience to question it. Power pickup shoes were also
not damaged.
The engine was repaired and works good.
 

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If you have had repeated derailments, I would guess the problem is the track. I would use screw type rail joiners, replace small straight track with 5' sections, if possible, and screw down track to the board. Then file any joints that don't align perfectly.
 

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Discussion Starter · #8 ·
If you have had repeated derailments, I would guess the problem is the track. I would use screw type rail joiners, replace small straight track with 5' sections, if possible, and screw down track to the board. Then file any joints that don't align perfectly.
Thanks for your advice.
 

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Am afraid to run the engine unsupervised for fear of ruining another engine.
Your concern is justified, but why run them unsupervised? Is there someone watching who isn't competent to stop the train if something goes wrong?

The other option you might explore is a timer. You can get ones that will kill the power after a certain period of time - 10 minutes after you leave the room! Or a 'motion detector' that turns the train on if someone moves.
 

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Discussion Starter · #10 ·
Your concern is justified, but why run them unsupervised? Is there someone watching who isn't competent to stop the train if something goes wrong?

The other option you might explore is a timer. You can get ones that will kill the power after a certain period of time - 10 minutes after you leave the room! Or a 'motion detector' that turns the train on if someone moves.
Hello Dave,

My train is part of a large outdoor Christmas display. I have many people walk through the display each night from Thanksgiving through New Year's. The train is behind
a roped off area so that it cannot be disturbed by young children or adults that would want to touch it. It therefor is left unattended. Losing 2 brand new LGB Christmas Stainz engines
in a few days probably makes my running the train unsupervised a bad idea. Was hoping for some kind of fix where if the engine became derailed but where the sliding pickups were still making
contact with the track and providing electricity to the motor that was making the wheels spin that the motor would shut down before it was damaged.
Still puzzled as to why the wheels would just spin and cause the gears or motor to burn up? Would have thought the wheels would continue to spin until the problem was discovered?
With the wheels spinning and the train not moving because it is derailed, does this cause extra heat that would not be present if the train was moving on the track?
 

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I float my track in ballast and nothing is nailed/glued down outdoors (track needs floatin for temperature extremes here in New England). Over 20 years and I still let my trains run when I am not watching them. I did have one derailment when a critter upset an engine, and a wheel melted (LGB Porter). I repaired this engine with a new wheel and it still runs to this day. Most curves are sectional track, big loop is flex track.
 

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Discussion Starter · #12 ·
I float my track in ballast and nothing is nailed/glued down outdoors (track needs floatin for temperature extremes here in New England). Over 20 years and I still let my trains run when I am not watching them. I did have one derailment when a critter upset an engine, and a wheel melted (LGB Porter). I repaired this engine with a new wheel and it still runs to this day. Most curves are sectional track, big loop is flex track.
Dan,

Thanks for your reply. Would you know why the gears or motor would burn up when the engine is derailed but the slider pickups are still engaged to the track drawing electricity and
causing the wheels to spin? Would think the wheels would just spin until the problem was discovered. When the wheels are spinning, does it cause more heat on the motor and gears
than when the engine is actually running on the track? Would think it would be the same and the wheels would just spin on the derailed engine until it was discovered.
 

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When the wheels are spinning, does it cause more heat on the motor and gears
than when the engine is actually running on the track? Would think it would be the same and the wheels would just spin on the derailed engine until it was discovered.
As Greg already pointed out, if the motor is spinning but not pulling a train, then it should be lightly loaded and therefore will not get as hot as if it was pulling a train.

Given the extensive repairs you had to do (assuming it was really necessary to replace all those parts,) I would look for some other explanation. Your big power pack could be feeding 16 Amps through that poor little Stainz if there was a short circuit or similar event (though I can't think of anything that would let the power pack produce 16A without tripping its safety.)
Is the power pack short circuit protection working?.

My other suggestion would be to protect the Stainz with a 2 or 3A polyfuse. This is a little solid state 'fuse' which cuts the power when it is overloaded. Put one in the power line to the track loop with the Stainz and it won't be able to pull enough power to melt down.
 

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The PolySwitch (the trade name by Raytheon who "invented" and copyrighted it) is self-resetting, so for our uses, much better than a one-shot fuse (where overcurrent melts the metal and requires replacement)

PolySwitches are used by many manufacturers, Aristo Craft made extensive use of them, even in their turnouts.


Greg
 

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Discussion Starter · #15 ·
The PolySwitch (the trade name by Raytheon who "invented" and copyrighted it) is self-resetting, so for our uses, much better than a one-shot fuse (where overcurrent melts the metal and requires replacement)

PolySwitches are used by many manufacturers, Aristo Craft made extensive use of them, even in their turnouts.


Greg
Pete and Greg,

Thanks for your advice. Will go with the Polyswitch and hopefully that will prevent burning the motor out.
 

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You should select ones that trip at twice the current you expect. I would think a 2 amp unit would be right.

But a several people have mentioned, something still does not make sense in your experience, the drivers slipping should not have burned out the motor. But we have asked all the questions we can.... still, this has happened to 2 locos? It almost sounds like you are overloading the locos all the time and you are prematurely wearing out the motor.. but you say you pull 2 passenger cars, and in both cases when derailing the drivers are turning.... just does not add up.... but whatever is killing your locos, you need to change it.

Greg
 

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Discussion Starter · #17 ·
You should select ones that trip at twice the current you expect. I would think a 2 amp unit would be right.

But a several people have mentioned, something still does not make sense in your experience, the drivers slipping should not have burned out the motor. But we have asked all the questions we can.... still, this has happened to 2 locos? It almost sounds like you are overloading the locos all the time and you are prematurely wearing out the motor.. but you say you pull 2 passenger cars, and in both cases when derailing the drivers are turning.... just does not add up.... but whatever is killing your locos, you need to change it.

Greg
The 2nd. engine that burned out wasn't pulling any cars. The engine was just running by itself so I am definitely not overloading the engine. The engine derailed but with the sliders still making contact caused the wheels to spin and that is the only issue that could have caused the motor or gears to burn out. Strong burnt smell was present. Can this cause some kind of short?
As you mentioned, I don't think to much power going to the engine is the problem as the circuit breaker on the Bridgewerks transformer would have tripped. With a 15 amp Bridgewerks transformer and only the engine running pulling no cars, how many amps are going to the engine? If you are suggesting a 2 amp polyswitch, could it mean without one that the Bridgewerks transformer is sending to much current to the engine and burining it out?
 

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I don't think to much power going to the engine is the problem as the circuit breaker on the Bridgewerks transformer would have tripped.
It is possible the Bridgewerks has a faulty circuit breaker. While you might not want to try a complete short circuit (if it is faulty all sorts of nasty things could happen,) you could test it with something that would pull 20 amps - or maybe it won't trip until 30 amps? A car starter motor is the only thing I can think of that might test it at 30 amps? Tricky.

With a 15 amp Bridgewerks transformer and only the engine running pulling no cars, how many amps are going to the engine?
One of our concerns is that the engine should only be using around 1 amp, or less with no cars. You can run 15-20 such trains at once with that big power pack.

If you are suggesting a 2 amp polyswitch, could it mean without one that the Bridgewerks transformer is sending to much current to the engine and burining it out?
The Bridgewerks won't send too much power if everything is as it should be - the amps supplied are controlled by the resistance of the engine, which is (normally) set up to need around 1 amp.
I think that's the possibility that Greg and I are suspecting. If the loco derails, but the sliders stay on the rails, and then one wheel touches the opposite rail in a short circuit (much lower resistance = much higher current), you could be getting 30 amps through that wheel and the frame, which might melt wheels, etc.

I suggest (a) check the specs whether the Birdgewerks does trip at 15 amps, or if it supports 15 amps continuously and trips at 30 amps, (b) consider using a smaller 1 amp power pack (20VA would be adequate for one Stainz,) (c) test the Bridgewerks to see if it does trip as specified [not easy,] and finally (d) definitely install a 2 or 3 amp Polyswitch in one wire from the power pack to the rails.
 

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Discussion Starter · #19 ·
It is possible the Bridgewerks has a faulty circuit breaker. While you might not want to try a complete short circuit (if it is faulty all sorts of nasty things could happen,) you could test it with something that would pull 20 amps - or maybe it won't trip until 30 amps? A car starter motor is the only thing I can think of that might test it at 30 amps? Tricky.


One of our concerns is that the engine should only be using around 1 amp, or less with no cars. You can run 15-20 such trains at once with that big power pack.


The Bridgewerks won't send too much power if everything is as it should be - the amps supplied are controlled by the resistance of the engine, which is (normally) set up to need around 1 amp.
I think that's the possibility that Greg and I are suspecting. If the loco derails, but the sliders stay on the rails, and then one wheel touches the opposite rail in a short circuit (much lower resistance = much higher current), you could be getting 30 amps through that wheel and the frame, which might melt wheels, etc.

I suggest (a) check the specs whether the Birdgewerks does trip at 15 amps, or if it supports 15 amps continuously and trips at 30 amps, (b) consider using a smaller 1 amp power pack (20VA would be adequate for one Stainz,) (c) test the Bridgewerks to see if it does trip as specified [not easy,] and finally (d) definitely install a 2 or 3 amp Polyswitch in one wire from the power pack to the rails.
Pete,

Thanks for you advice. Will check these items out.
 

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A basic understanding of electronics is needed before making some of the statements you have both made.

First: faulty circuit breaker: that Bridgewerks will deliver 15 amps all day. If you have a SITUATION where you are drawing 15 amps, it will go on FOREVER and the circuit breaker will not trip, and well it should not.

If you manage to put the loco in a SITUATION where it DRAWS 15 amps, you will indeed destroy something.

The lack of understanding here is how to make the SITUATION where you can DRAW 15 amps. Clearly with the wheels turning, it was not drawing 15 amps, 15 amps going through that motor would destroy stuff. So there is NOTHING wrong with the circuit breaker.

Current is drawn in proportion to the voltage and resistance in the circuit. Please read about Ohms Law.

So, in the NORMAL SITUATION, the motor's resistance is such that it will only DRAW about 1 ampere... so no damage will occur. (you could have a 1 million ampere supply and this would still be the same)

Now, if the VOLTAGE from the Bridgewerks suddenly went almost triple, that would triple the current, i.e. the locomotive would DRAW more amps, and this could damage it.

locking or impeding the drive train will reduce the resistance of the motor and then it will DRAW more amperage, and that is a common mode of damage, BUT you say the wheels were turning... (this part of the story does not compute)

a SHORT CIRCUIT, i.e. bypassing the motor (the circuit becomes shorter) would DRAW a lot of current, and normally exceed the 15 amp rating and then the circuit breaker would trip, BUT you say the wheels were turning, so there was NO short circuit.

Again, the story still does not "jive" with what happened... it the loco was mechanically stalled or "binding" the story would make sense, or a short circuit somewhere... BUT if the loco derailed and the wheels were turning it cannot be..

Is there any chance that the wheels were turning, but really slowly and binding? This is about the only guess I can make where you could draw a lot more current to cause the motor / brushes to be damaged.


Greg
 
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