Fastrack uncoupling track trips direct lockon

ZIRBEL227,

   Using the old KW for tack power get rid of the 34120 direct Lock on. Safe Guard your layout with a 10 Amp Resettable Breaker on your Red Middle Line, as we do with DCS /Legacy layouts.   Everything should work fine when you do, and the Resettable Breaker safe guards your layout.

PCRR/Dave

zirbel227 posted:

I seem to be having a problem with my fastrack direct lockon (34120) and my uncoupling track. Basically, the circuit breaker trips (light turns red) when ever I push the uncouple button. I’m using a KW for track power set to 18 volts to operate my Lionchief Plus engines, everything else is operating just fine. The issue happens regardless if I have the uncoupling track powered from track power or auxiliary power (track power is from the “B” side and Aux is from the “A” side, set to 10 volts). If I take away the direct lockon (34120), which is protection for my new engines, everything works just fine - engines, switches, and uncoupling tracks! Is there something I missing? Or should I try a different CB set up? Happy to provide more information / pictures if needed. Thanks in advance!

I assume that you have 6-34120.

Since the KW is 190W, do you have the internal switch at 180? It mat be tripping if it is on 135w.

A (Hot) and U(common) is correct or B/U with the variable voltage set to 18 volts for the KW

They are a fast breaker. I would try to discover how to make it happy. Or use a PSX-AC if you cannot.

Let me know what the setting is and if a change helps.

Dave & Carl thanks for getting back to me!

I tried switching from 135 to 180, both with track power and aux power, it wasn’t happy with either... Any thought to trying a different transformer? I have a ZW I was planning on using when the layout got bigger. 

Thanks again for the help!

My experience with the TMCC Direct Lockon is that it's very sensitive to certain operation.  I have a few TMCC, and even one Legacy locomotive that will trip it just driving by.  That issue, coupled with the fact that it stomps on the MTH DCS signal convinced me to lose the and stick with the PH180 bricks.

Zirbel227,

Nothing wrong with an old ZW if it is in good running order, use it!  Use the KW for Aux power.  Remember the 10 Amp Resettable Breakers when running DCS & Legacy.

PCRR/Dave

Thanks for all the advice!

John, I know I could look up some older posts, but what size breaker, amp-wise, should I be looking for? 

Dave, my thinking exactly! I like the fixed volts on the KW, and I shouldn’t have any problem running my 5x9 layout with a ZW! Hopefully some day I’ll double the size! I’m working with a very temporary layout right now, planning on new bench work and a more permanent (for now) layout!

Thanks Again!

I realize it's been a while since you posted your question, but I wanted to share this with you since I had the exact same situation and this solved the problem. You'll notice that the lockon shack does not trip when you press the uncoupling button but it's when you release the button that it breaks the circuit. Here's why: when the current to an electromagnetic coil is cut, there is a surge of current out of the coil that is much higher than the original voltage. These spikes are common problems in some motors and lots of relays.

A combination of a resistor and capacitor (R/C) in a bypass or shunt will prevent the spike and it's the spike that trips the lockon's sensitive electronics. Personally, I like the extra protection the lockon gives my expensive locomotive electronics, so I was very happy when this solution worked with 100% perfection.

I used a 0.1 MFD disc capacitor and a 100 ohm resistor. Solder the resistor and capacitor together and cover that common leg with shrink wrap or tape to prevent it from shorting against the center rail tab (see pic). Solder the resistor to the ground plate and the capacitor to the tab where one of the two black coil wires is soldered.

I run my uncoupling tracks from a Lionel accessory transformer and set it very low so there's just a faint buzz when the car passes over. It's never tripped the lockon since I made the mod and the four uncoupling tracks all work perfectly. 

PENROD thanks for replying! The pictures will be super helpful this winter when I tackle my wiring projects this fall and winter!

Another easy way to damp out those spikes is a TVS, it's the job they were created for.

 1500W 33.3V TVS at Digikey

Thanks John! It’s also entirely possible I had a few bad jumpers on my 1 3/8 tracks that were loose that may have been causing the original issue. I’m now trying to make things as robust as possible!

John,  I’m having the exact same issue that Zirbel227 was, and after I read your suggestion on the TVS devices, I ordered 10 from DigiKey. Only thing that I’d like to confirm is that I solder the leads in the same manner as the capacitor / resistor combination suggested by Penrod… namely between the ground tab and ground plate on the uncoupler??  Just want to be sure so that I don’t “fry” anything. I’d love to do away with my lock-ins  entirely, but I have a 135w Powerhouse on one of my loops, and I don’t believe that has the same fast circuit breaker that’s employed in the 180W on my other loop. Better safe than sorry, I guess!!  Thank you!

The TVS diode goes right across the power to the offending device.  It sounds like you're connecting a ground to a ground, not sure what that does for you.

Its not a good idea to run these at command voltage if this is the case. It could overheat.

These shouldn't trip the lockon if they are powered by an accessory transformer wired per the instructions.

The TMCC Direct Lockon is VERY sensitive to any transient from something like a crossing gate or uncoupling track.  Lose that lockon and get a real circuit protection solution.

Thank you John & Rick.  Appreciate the replies!  I was wondering why I'd put that TVS across the grounds, but I was looking at the capacitor / resistor solution that Penrod had posted earlier in the topic, which is why I asked.  I obviously would've been a bit nervous placing anything between the hot and neutral, but hearing a qualified electrical engineer telling me it's OK makes me feel better!  . As for the lock-ins, I'd LOVE to lose them.  I think I'd be OK on the loop powered by the 180W Powerhouse, because I believe I've read that their circuit protection is reliable and fast.  Do you agree with that?  As for a "real circuit protection solution" what would you recommend??  Always up for a suggestion.  I was previously having trouble with my Gateman doing the same thing, but purchased one of your track activation relays (forgot the exact name) from Hennings, and it works like a charm!!  So anything else that you have for circuit protection, I'd love to know about.  Thank you!

@Moonman posted:

I assume that you have 6-34120.

Since the KW is 190W, do you have the internal switch at 180? It mat be tripping if it is on 135w.

Copied this from an earlier post by gunrunnerjohn:  "Note that the KW doesn't actually deliver anything close to 190 watts.  Postwar transformer are rated on input power, considering an efficiency of maybe 70-80%, the actual output power is around 140 watts."

@Pennsy Johnnie posted:

I think I'd be OK on the loop powered by the 180W Powerhouse, because I believe I've read that their circuit protection is reliable and fast.  Do you agree with that?  As for a "real circuit protection solution" what would you recommend??

I run with four PH180 transformers, I'm perfectly happy with their excellent and lightning fast trips with any overload.  That is "real circuit protection" in my mind.