The MRC is rated at 5 AMP. It ought to work just fine if you have a 5 AMP booster or something like that. I have a puny 1.7-ish AMP system. It must be why it does not work all that great.
oh, yeah, one more thing... you know what is funny? I can't even return the MRC unit for refund/exchange because I trimmed all the wires too small. Too much determination in experimentation. It is not in it it's "original condition" no more. Otherwise all fine. Ya want it? You can have it. I'll be stuck with it unless you take it. Just pay for shipping and off it goes. I'd be glad to give it away if its to have a better purpose than occupying space in my R.I.P. closet. Like I said, there is no way I'll make use of it so go ahead let me know if you want it. edit: added a picture of the device and it's shortened limbs.
Doh.. ya know what, I was thinking volts.. and after reading Tony's Train Exchange review just now, I think I was even mis-informed on that aspect too. :mwacko: Must be time for sleep.
Don't be too sure on that until you get the official word from MRC customer service. If there is a chance the unit is bad, they have to take it back. And if it's not bad, MRR manufactures still have a general outstanding understanding and will to please customers. I bet they'd take it back.
Ya think? That'd be cool of them. I know it is just some wires and thus not quite hard to change/fix but I still tampered with it. I'd have to pay for (international) shipping I guess. Any way, I'll have to sleep on that.
The operation of auto-reversers does depend on the 'discrimination' of the system. The booster/command station has a trip circuit that has a current and time characteristic (eg. amps > X for > Y millisecs). The auto reverser also has a similar character. On most setups a short circuit should produce a current that exceeds BOTH devices amps trip level, so the discrimination is then down to the time. Ie. the autoreverse needs to be faster (shorter trip time) than the booster/ComStn. You may find one or both times are adjustable; unless someone here knows these devices you'll have to read the manuals
I don't know anything anymore. The Power Cab's short circuit does not always trigger when the MRC fail to reverse the polarity. I see the ammeter reach over 2.3..2.5; the loco goes like BZZZZZ and the lights blinks everywhere (Power Cab's display and loco) while the MRC unit is like 'yeah, whatever, dude...'. Luckily, I'd say, no smoke yet. Whatever is not fast enough must be reeaaaallly slow.:tb-sad: Take me with a spoon, guys. My tripping point is lower than that reverse loop module right now. I spent over 1,500$ in hardware since I started this layout and it all pretty much suck. The Power Cab is forgetting things and fail to protect it's own ass against shorts. My decoders are allergic to momentum and nobody seam to know what is up with that. NCE and Digitrax both denied the existence of an issue between their products. An MP15DC decoder equipped (paid 187 Canadian dollars!) that dies on me after less than 8 hours of running time. That is after it got tired of nagging me with erratic performance and ¤¤¤¤. Contradictory and erroneous information in manuals. An auto reverse module that does not quite reverse automatically yadda yadda. I need a drink. Im going like AARRGHHarghh: Wasting time and money is not fun.
update I sent an email to NCE to see if they have a list of known to work with Power Cab auto reverse modules.
You may not want to hear this but, according to the track diagram, you may not need an auto-reverser at all! (Ducks and covers). What you have is a Wye, with the tail on the inside. You don't show any trackage beyond the center turnout, but I have to assume that there is something there at least long enough to hold the train. What I would do is place the gaps just past the frog on both routes of this turnout. Then, via DPDT contacts on the switch machine, power the "tail" from whichever approach track the turnout is set to. You will never see a short unless you run against the turnout, and the tail polarity will always aligned with the selected approach track. See example "E" under "other wye configurations" in http://www.wiringfordcc.com/track_2.htm#c3
I have almost the same track configuration as pertaining to the the "Y". The reversing section is flipped. I believe you have a defective reversing unit. I had the same problem with one right out of the box. Just because it is new does not mean it is good. Send yours back for a replacement. If they will not replace it because of your trimming the wires then I suggest you try an AR1 from Digitrax. No wires to cut. The wiring for the AR1 is fairly straight forward and has a sensitivity adjustment which may help with the problem. Instructions for the AR1 are found here. Gary
Adjustable trip current sound true to me. That'll do it. Digitrax AR1 and PSX-AR have that feature. The former is mechanical and range from 0.25 to 8 AMP while the later is solid state and range from 1.27 to 17 AMP. It also double as a circuit breaker. They both look like fine pieces indeed. Next step, perhaps last step, is to figure out if a solid state module is worth the extra dollars for me. It surely is silencer and quicker to react than it's mechanical counterpart but is like twice the price.. 8 AMP is already a lot. 17 is would be over the top a little. Meanwhile, I'll try to take the MRC unit back to the LHS. Perhaps she will be in a good mood and accept to take it back. Yes, it's a railroading lady! :tb-cool:
Conclusion Alright. The Digitrax AR1 arrived earlier today. It's installed and generally going well almost all the time. Some times it does not trigger for a reason or another. I'll keep tuning the trip current screw until all is dandy. I also found out why and how metal wheels can play havoc with auto reverse modules. Even tho the wheels are insulated with a plastic hub they still can bridge the gap between the reserving section and the mainline as it cross over it (see attachment for visual reference-- it's subtle but it's there). This makes the AR1 go drunk and trigger itself every time an axel cross the gaps. A short occurs if both gaps happen to be crossed at the same time. Im solving that with a redneck workaround. That is by "painting" the track with scenic cement on a small length of track on both sides of the insulated joiners.. :tb-shocked:. It does the job just fine so far but I doubt it will hold all that well over time. The stuff will wear out soon or late. I predict my engine's truck gearing will be the first to know where it went... Im thinking about salvaging the plastic tracks from an insulated crossing frog or subdue a small section of track by some spare Atlas N Code 55 ties instead. The height of the later happen to be pretty much the same width as the rail while the former will require some more fiddling and cutting and destroying an otherwise perfectly good part. I'd glue the tie with some Testor cement for plastic models and call it a day. I'll see to that when I get there.
I think a good work around would be to cut a 1/4 inch gap in the rail and use your favorite epoxy to glue a bit of styrene in that gap, then shape it to the rail.
Actually, this is the first thing I thought about (minus epoxy--I would have used some Testor glue) but I have no styrene at all just yet. I'll get some soon or late. So far the scenic cement is doing the job very nicely. The locos and rolling stocks seamlessly glide over it and the AR1 is perfectly sober again:tb-biggrin:
This has been explained in a couple of threads recently. The 'across the gap' short is what triggers the AR normally. It is only a problem when you bridge BOTH ends of the reversing section at the same time - typically by a loco with electrically coupled wheels at one end and metal stock wheels at the other - at which point the reversing section cannot be switched in a way that fixes both shorts so the AR has no way out. Hence the 'rule' that the reverse section must be longer than the longest train (not loco). Your solution is an interesting one for where the 'rule' cannot be applied, though another loco or a light equipped vehicle like a caboose could still provide a simultaneous bridge of the gap. Obviously you can't make the 'gap' longer than a loco or you'll never get anything past ....
Thanks. The whole "across the gap" part went completely over my head until I observed it with my very eyes. I really thought it was all about and only about powered trucks and/or lighted cars (I.E. passengers and cabooses). It was one of those "ooooook now I get it!" moments. Perhaps the picture I included will help explaining things to inquiring minds. My trains made about 50 passes over the reversing section so far and the Scenic Cement is still holding up. I guess it will stay put until I start cleaning the tracks and scrap it out myself because I forgot its there... thats me...
I guess another solution would be to cut two gaps in the same rail 1/4" - 1/2" apart if need be. Just enough to ensure wheelsets of one truck are not touching all three rails.
