DCS Problems with Tubular Switches

First thing I would check for is intermittent shorts as loco traverses switch. Some locos may short the back of a wheel to the center rail between the switch points and frog. It helps if you have an ammeter or voltmeter on your track power to see if it jumps when the loco goes through the switch.

Check your battery in the engine. I have 1 big loop without switches. PS2 engine ran fine. Put it on another track with switches and the momentary disruption of power cause a reset in the engine. Did not realize I had a battery problem until the engine went over the turnouts.

Todd,

   Some of the newer tubular switches have had all different kinds of problems, if your older tubular switches are running fine, the problem will not be the P2 Battery & P3 Engines have a built in super cap, so they should not reset as they cross a switch, unless there is a complete lack of power.  Further you can solve all your switch problems by transitioning in and out of FasTrack Command Control switches, which I did for years, they work great with all different kinds of engines, and you can control them from your Legacy remote control.

PCRR/Dave

Todd Knoll posted:

I recently added 2 Lionel tubular 0-42 switches to my layout.  I run all tubular track and these are the first switches that I have added.  The switches were both new from the MPC era.  Intermittently PS2/3 engines will stop on the switches and shut down.  

Has anyone else had this problem? Do I need more redundant power and ground wires back to the TIU?  

 

Thanks! 

I have the same problem with the Lionel O-42s that I've got on my floor running layout.  I typically see sparks as the engine and cars traverse the switch, which tells me there is a short occurring as the wheels bridge the rails for whatever reason.  Also, if I run my engines (PS3 and PS2) at a slow speed across the switch, it shuts down as well.  At higher speeds they make it through, but at 10 smph or thereabouts, short and shut down is the usual outcome.  It just happened last night as I was backing my PS3 into the switch to grab a consist.  The red light on my transformer glowed brightly and I cut power.  I'm no electrician but I believe it must have something to do with the metal frog design on the switch because that's about the location that I'm witnessing sparking.  I don't know a solution, but I'm sure someone on here must as plenty of folks use these on DCS layouts.  My solution was to start buying Ross switches for my permanent layout. 

Todd,

Intermittently PS2/3 engines will stop on the switches and shut down. 

If the PS2 and PS3 engines are shutting down completely, it's most likely because they are losing either Hot from the center rail or Common from the outside rails. Does this occur at slow speeds and not at speeds in excess of 25 SMPH? If so, this is almost certainly the culprit.

You should be aware of a few things:

• All switch tracks have a discontinuity along the center rail in both the straight and curved orientation. If an engine's pickup roller spacing is such that all of the pickups are landing on a "dead" section of center rail at the same time, this can cause the engine to stop dead. The engine's battery doesn't keep the motors going. Rather, it only keeps the engines electronics powered to preserve sound and keep the engine in DCS mode. It's the engine's momentum that can allow it to tolerate a momentary loss of power, although the battery dos have a role to play.
• Many switch tracks, tubular ones in particular, have outside rails that are control rails that are used to automatically switch the orientation of the switch so as to prevent a derailment  These control rails are also unpowered. Further, if the track is powered only on one outside rail, the other outside rail may not have Common at all. If an engine's non-traction tired wheels land on dead spots all at the same time, the result can also be a stopped engine, if the engine's speed and momentum are not enough to carry the engine over the dead spot.
• A weak battery can also contribute to the problem, by shutting down an engine's electronics as soon as the power loss occurs. This will typically cause the engine to stop and drop into neutral, in conventional mode, no matter how fast it's moving.

Two questions that, when answered, will greatly define the cause of the problem:

• Does the engine stop dead or stop and drop into neutral with lights and sounds?
• Does the problem occur at low speeds and not at high speeds?

Also, if the engine stops dead, turn off power and tilt the engine to determine exactly where the pickup rollers and non-traction tired wheels are sitting.

Thanks, Barry!  As I left mine right were it stopped last night--I went to bed--I'm going to check the positioning of the rollers when I get home.  To answer your questions:

• Stops dead.  It goes through shut down, but that's the capacitor doing its job, right?
• The problem occurs at low speeds.

Basil,

If shutdown sounds persist for 6-7 seconds, then the battery (for PS2 engines) is fine and isn't an issue.