Atlas 2 rail frog shorting to adjacent rail web: solved

Engineer-Joe posted:

Well? it takes a long time to load a video on U-tube with my stuff. So while doing that and typing I tried some stuff that popped into my head.

First of all, if I use my meter and touch the frog, and to the adjoining short rail (on the same side) going straight after the frog, I get 18 volts. The frog should be dead so there's a problem I believe? Even if it wasn't I should get voltage reading on the same side of the switch.

Off to see what is touching. Always something with these toys!

You got that right! 

Mark in Oregon

Engineer-Joe posted:

 Everything I touch seems to go bad?

Demonic possession. 

Hi Joe,

It appears from your video that as the cars pass the switch, they are indeed causing a short circuit of some kind, which, in effect,  brings the track voltage to that power district to zero volts regardless if the breaker trips or not and the lights on the cars obviously go out.  Given the fact that your Lionel he circuit breaker does not trip could very well be due to the long run from the breaker location.  It is very common for long electrical runs from the circuit breaker to have enough resistance over the distance to not allow the breaker to trip.  In HO Scale, they call it a quarter test where you put a quarter across rails at various places and check to verify that the breaker trips with DCC / DCS.  Obviously, with the larger spacing of the rails O scale a quarter will not work, maybe we need to call it the silver dollar test for O scale 😊.   Joking aside, you can just put any piece of metal across the rails and check to see that the breaker trips at various locations around the layout.  Especially, noteworthy are locations furthest from the power boosters and circuit breakers.  If the breaker does not trip when you short across the rails, then you need to either increase the size of the bus wires to that location so you get less resistance in your long run or add an additional booster district closer to that area of the layout. 

Scott

OK, I ripped out the "brand new" switch that was bought years ago and sat in the box. On close inspection it is not brand new. It appears to have been tampered with. The small pads that make contact to the bottom of the moving rails (points?) are charred or painted brown? There's other evidence that somebody maybe tried to fix the switch and it must have been shorting on them. On the back side there is evidence of some more shorting and charring the brass strip that actually is for juicing the frog. Maybe that's where the short is at?

 Checking it to other switches, it appears that the small "curved" rail leading to the frog, is shorted to the frog. On other switches it's not. There's a big enough gap so I'm not sure what's making it short? That would explain the cars and engines not shorting when taking the diverging route and hitting a dead short as soon as they cross the frog area. So much for mint in the box. I don't know where I got it but I'll be on the look out for any more stuff that is returned like this.

 Now I have to check into this breaker problem not tripping, so thanks for the tip. My Weaver PS3 conversion is shorting again whenever it goes around a curve. I only tested it at first, on a small piece of straight track. I put in a siding this morning and that killed my outer loop. I put in another crossover on the other side of the layout and shorted out my #1 switch channel on the AIU.

Here's another idea, I put those tiny poly fuse things in each passenger car conversion to LED that I did. That doesn't explain why the MTH engine didn't trip the breaker though? and I don't think they reset that fast anyways?

 Maybe I should take a long break again. Like three or four years.... again. URRRGGGG!!!!!!

I am at a loss here. I have seen this posted by others with problems like this. This is my first experience with this. I see the frog juice strap looks almost burned so I actually cut it. The frog is still tied to the outer straight and diverging curved rails? I can see a good gap between the curved rail and the frog so where else could this be tied?

OK finally got it. The gap on the other side of the frog is touching the rail web. I believe that Atlas should take more care and file the webs back at an angle so this does not happen.

mwb posted:

Engineer-Joe posted:

 Everything I touch seems to go bad?

Demonic possession. 

Oh yeah, and thanks once again for the help. I always need to be grounded.

Helps with the shock.

Hi Joe,

Good job and I was just about to hit send to let you know that you needed to check the rails at the far end of the frog as well as they looked rather close to the frog.  The frog must always be 100% electrically isolated because if you power it, then the frog will be changing polarity based upon the turnout route selected (straight or diverging).  Therefore, a powered frog will need some type of electrical switch or switch motor contacts to handle switching of the frog polarity based on route selection.  Obviously, if you leave the frog unpowered, then the frog itself will have no polarity and not cause any short circuits but it will result in  a short section of dead rail.  The choice of handling the frog power is ultimately up to your own personal preference.   

Scott

Next time you think you have a short, turn out the lights and look for sparks. Your hair probably isn't falling out, but falling in, and clogging your brain!

Simon

Thanks Scott, you are right and I know that from the past (All my frogs are dead).

However when everything is going haywire, I'm not thinking clearly. Fortunately here on the forum I get good help from this guy

Simon Winter posted:

Next time you think you have a short, turn out the lights and look for sparks. Your hair probably isn't falling out, but falling in, and clogging your brain!

Simon

and the other one above! Sheesh. If the frog would have enough juice to spark.... ah forget about it.

One down, ten more steps forward? or was it back again....

Scott Kay posted:

Hi Joe,

…..  If the breaker does not trip when you short across the rails, then you need to either increase the size of the bus wires to that location so you get less resistance in your long run or add an additional booster district closer to that area of the layout. 

Scott

 

Wait! More power? I told my girl I need more power. I've got....

4 Lionel PH180 bricks

3 Bridgewerks DC packs

2 MTH Z packs

and a Z4000

in a pear tree. 

and these too...

I may have to get bigger models for the subs or run a couple in bridge mode. Either way I do need more power!

I have to out do that guy with the diesels broadcasting thru his stereo. 

I got an atlas  #5 thats used and the diverging,(curved route),lets the engine through while the straight leg lets the engine past the frog then stops the engine &trips the breaker on the power brick. Have checked all rails to make sure no rails aren't missing gaps and it seems they are all ok. I took the switch out for now. I've read all posts her but not sure what my problem is. Any ideas other than listed in replies to Joe's problem?

Thanks to all in advance for every body's replies.

As Always,

Al Hummel

There are metal rod staples on the bottom in the 3-rail switches to run power over the gap.  Turn the switch over and see if there is a connector staple creating a short.

Alan Hummel posted:

I got an atlas  #5 thats used and the diverging,(curved route),lets the engine through while the straight leg lets the engine past the frog then stops the engine &trips the breaker on the power brick. Have checked all rails to make sure no rails aren't missing gaps and it seems they are all ok. I took the switch out for now. I've read all posts her but not sure what my problem is. Any ideas other than listed in replies to Joe's problem?

Thanks to all in advance for every body's replies.

As Always,

Al Hummel

check with a meter on each leg. The frog should be isolated fully. Mine touched the web of a short piece of rail and that's all it took. It did the exact same as yours is doing. It appeared to have a gap.

All other pieces have connections to transfer power. So when they touch, there's a problem. spread that joint and add some plastic to keep it open.

Joe, with Atlas switches I've always found it best to cut wider gaps in the closure rails and the wing rails because of the shorting problem.

Shorted frogs on AtlasO 2 rail turnouts is a problem that has been discussed on the forum several times. 

Here are 3 issues I've experienced with one or more of the 13 AtlasO 7.5 turnouts on my railroad.

- failed insulating gaps between the cast frog and the 4 approach rails causing a short when metal wheels cross the gap (or if the frog is powered ).  In all cases the gaps were open when the turnouts were initially installed but shorted several years later.  The fix: use a Dremel cutoff wheel to enlarge the gap, epoxy a small piece of plastic in the gap, file to shape.  After two failures I preemptively re-gapped all the turnouts.

- electrical feeds to the turnout using the Atlas "tabs" go open circuit.  The fix:  solder feeders directly to the rails and frog

-a plastic throw bar connection to a point rail failed (fortunately only one occurrence).  The fix: fabricate a new throw bar (I used printed circuit board ).

Joe your Ashly 1/3 octave equalizers are made about 1 mile from me.

Keystoned Ed posted:

Shorted frogs on AtlasO 2 rail turnouts is a problem that has been discussed on the forum several times. 

Here are 3 issues I've experienced with one or more of the 13 AtlasO 7.5 turnouts on my railroad.

- failed insulating gaps between the cast frog and the 4 approach rails causing a short when metal wheels cross the gap (or if the frog is powered ).  In all cases the gaps were open when the turnouts were initially installed but shorted several years later.  The fix: use a Dremel cutoff wheel to enlarge the gap, epoxy a small piece of plastic in the gap, file to shape.  After two failures I preemptively re-gapped all the turnouts.

- electrical feeds to the turnout using the Atlas "tabs" go open circuit.  The fix:  solder feeders directly to the rails and frog

-a plastic throw bar connection to a point rail failed (fortunately only one occurrence).  The fix: fabricate a new throw bar (I used printed circuit board ).

 

 

 

 

 

Ed, All great suggestions to help improve operation and overall reliability of the switches.

Joe..when you touch off your layout do the neighborhood lights flicker? JK