Atlas remote snap switch burn out........

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PrairieKnight

Active Member
There have been some recent posts regarding Atlas snap switches. My son and I had a weird thing happen during an ops session this past Saturday. Everything was running great when all of a sudden one of the Atlas 18" remote snap switches would not throw when the Atlas button was pushed on the control panel. As I walked over to the offending snap switch.... smoke started coming out of the remote mechanism on a different remote snap switch approximately 2' down the mainline from the one that stopped working. The mechanism that was smoking was on a 22" Atlas remote snap switch. Everything was unplugged and the wires were disconnected between the switch button and the 22" switch. Here is what it looked like:
Remote switch burn.jpg

The wires coming out of this mechanism were not hot nor were the wires on the 18" that originally stopped working. Everything worked fine (including the 18" original problem) once the burned out mechanism was disconnected. Has anyone ever experienced this type of thing before? Both of these remote snap switches and buttons have been working flawlessly for three years. One other thing... the 18" and the 22" switch buttons were connected in series on the control panel in the manner that is normal for these Atlas remote snap switch buttons. And yet.... the 18" worked fine afterwards. No wires were touching between the switch activating buttons on the control panel. I am not that smart about electronics... any advise or suggestions as to why this may have happened is greatly appreciated.
 

santafewillie

Well-Known Member
What your picture shows is what happens when an Atlas switch machine is powered for too long at a time. It can be because the push button is held too long, or someone accidentally is leaning on it, or just a complete failure of the push button mechanism. The switch machines (at the switches) themselves are meant to be "momentary". Those internal coils heat up rapidly when power is applied too long.

Willie
 

GNMT76

Active Member
And that's one reason I switched to Tortoise switch machines. One of my Atlas machines smoked and melted for the expressed reason, as did yours. This will not occur with Tortoise.
 

Iron Horseman

Well-Known Member
one of the Atlas 18" remote snap switches would not throw when the Atlas button was pushed on the control panel. As I walked over to the offending snap switch.... smoke started coming out of the remote mechanism on a different remote snap switch approximately 2' down the mainline from the one that stopped working. The mechanism that was smoking was on a 22" Atlas remote snap switch. Everything was unplugged and the wires were disconnected between the switch button and the 22" switch. The wires coming out of this mechanism were not hot nor were the wires on the 18" that originally stopped working. Everything worked fine (including the 18" original problem) once the burned out mechanism was disconnected.
Yeah it happens.

How recently, had the 22" switch been activated before the 18" was attempted? My guess is the last time the 22" switch had been changed, the control stuck ON; or someone had accidentally leaned on it for a long time; or set something on it that held it pressed down. There had to be power to those coils for more than 10 seconds which would melt down the coils like that and eventually caused a short circuit. The short circuit is then why the other turnout (the 18" one) would not work. A short circuit sucks all the power out of the system leaving nothing to power devices with.

I would check the Atlas ATL56 that was controlling the melted coils and make certain it is still momentary contact on both outputs (sending power down ONLY ONE wire only when pushed). If it checks ok, just replace the turnout motor. If it happens again replace the ATL56, since that would indicate an intermittent failure of the unit.
 

trailrider

Well-Known Member
This is one reason I use either SPDT Center-off springloaded miniature toggle switch to control all twin-coil switch machines, OR separate pushbutton momentary Normally Open (contact when you push down), one for straight route, one for diverging. Sometimes, if I have rotary switches, I will wire them to select the route, with a single pushbutton wired in series with the route contacts. It isn't impossible for these switches to stick closed, but I've never had it happen. Much more reliable than the Atlas momentary slide switches.
 

PrairieKnight

Active Member
I appreciate the replies. I think Iron hit the nail on the head as to what happened with the switch button sticking or the button was pushed for more then the touch it takes to throw the switch. I like trailrider's idea....but my limited knowledge of electronics means that I need to find information on the internet before I start messing with SPDT or separate push buttons to throw my Atlas switches. I am wondering how the three wires that come off the Atlas switch machine would be hooked up to a power source (a separate power pack) and one of the types of buttons that trail mentions.

Thanks again for the replies.
 

GNMT76

Active Member
I appreciate the replies. I think Iron hit the nail on the head as to what happened with the switch button sticking or the button was pushed for more then the touch it takes to throw the switch. I like trailrider's idea....but my limited knowledge of electronics means that I need to find information on the internet before I start messing with SPDT or separate push buttons to throw my Atlas switches. I am wondering how the three wires that come off the Atlas switch machine would be hooked up to a power source (a separate power pack) and one of the types of buttons that trail mentions.

Thanks again for the replies.
PK,

Even better resources than the Internet (for any number of reasons, mostly ease of use and detailed drawingss and schematics), I recommend the following three books on model railroad wiring (for DC operations, that is). In order, from most basic to most detailed, they are:

1. The Complete Atlas Wiring Book (#12). Includes a glossary of basic terms and detailed explanations on how Atlas' electrical system and all its components work.

2. Easy Model Railroad Wiring (2nd edition) by Andy Sperandeo and

3. How to Wire Your Model Railroad by Linn Westcott

That last one is a bit dated (15th printing, 1989), but for my Atlas component wiring and more complex configurations from just five years ago, it was indespensible. You should be able to find all three on Amazon. Westcott was one of the early "deans" of model railroading to boot.

After a short while, you may be "shocked" to see just how simple model railroad wiring is! ;)
 

Iron Horseman

Well-Known Member
I am wondering how the three wires that come off the Atlas switch machine would be hooked up to a power source (a separate power pack) and one of the types of buttons that trail mentions.
It is very easy. Remember electricity has to go in a loop. So the center wire from the switch machine goes to one side of the power. The other side of the power goes to the center pole of the "center off momentary contact SPDT" (single pole double toggle) switch. Then the two sides of the SPDT go to the two sides of the switch machine.
 
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fcwilt

Active Member
Hi,

If you are not in a position to change out the Atlas machines you might consider a Capacitive Discharge device for controlling your turnouts.

Frederick
 

PrairieKnight

Active Member
GNM and Iron.. I truly appreciate the book suggestions and the wiring explanation. Forgive my ignorance here...but.... I am using an NCE DCC system to run the trains and a separate old DC power pack to run the Atlas remote switches. Can I use the information in the books suggested given this set up?

Fred.... I will be searching for information on a Capacitive Discharge device as soon as I post this.... I appreciate the suggestion.
 

GNMT76

Active Member
GNM and Iron.. I truly appreciate the book suggestions and the wiring explanation. Forgive my ignorance here...but.... I am using an NCE DCC system to run the trains and a separate old DC power pack to run the Atlas remote switches. Can I use the information in the books suggested given this set up?

Fred.... I will be searching for information on a Capacitive Discharge device as soon as I post this.... I appreciate the suggestion.
PK,

Ah, DCC! The Complete Atlas Wiring Book is strictly DC, as is Linn Westcott's tome. The former would be most useful for your Atlas remote control turnouts; the latter might supplement some relevant electrical information. Andy Sperandeo's book only has two pages (81-82) of DCC coverage.

Here are three DCC books in my library (though I operate DC only, I found the education interesting):

1. DCC Made Easy by Lionel Strang. A short, basic primer.

2. The DCC Guide: How to Select and Use Your Command Control System by Don Fiehmann. 70 pages of good, detailed information.

3. Wiring Your Model Railroad by Larry Puckett. A mixed bag of DC and DCC information, plus a few other related topics in some detail.

There are surely more DCC books on the market. Just check Amazon.
 

santafewillie

Well-Known Member
GNM and Iron.. I truly appreciate the book suggestions and the wiring explanation. Forgive my ignorance here...but.... I am using an NCE DCC system to run the trains and a separate old DC power pack to run the Atlas remote switches. Can I use the information in the books suggested given this set up?

Fred.... I will be searching for information on a Capacitive Discharge device as soon as I post this.... I appreciate the suggestion.
For the switch wiring, yes.

Willie

F
 

trailrider

Well-Known Member
Yes! You could even use the AC accessory terminals from a DC power pack. The only thing necessary to activate a twin-coil switch machine is a momentary "shot" of current that is sufficient to activate the coil. As far as Capacitive Discharge devices are concerned, they are really only needed where (a) your AC or DC output is weak; (b) where you have a series of switch machines that you want to activate at the same time, such as to set up a route in a yard or complex track layout. Then what you would do is set up the route of all the turnouts (possibly with rotary switches on your control panel), and zap them at the same time. Because of the current draw required you might not have enough juice without the capacitor setup. Frankly, I don't mind the few extra seconds it takes to activate each machine.
 

fcwilt

Active Member
As far as Capacitive Discharge devices are concerned, they are really only needed where (a) your AC or DC output is weak
You are perhaps overlooking the other benefit of CD devices - stuck buttons won't burnout your switch machines - that is the reason I mentioned them.

Frederick
 

Iron Horseman

Well-Known Member
GNM and Iron.. I truly appreciate the book suggestions and the wiring explanation. Forgive my ignorance here...but.... I am using an NCE DCC system to run the trains and a separate old DC power pack to run the Atlas remote switches. Can I use the information in the books suggested given this set up?
Yes, absolutely. In my opinion, using DCC for powering turnouts is a waste of expensive power. I use separate DC or AC power for turnouts and accessories all the time.
 




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