I have just completed building a yard for my layout and I have been testing all the tracks to ensure all are working properly. I have run into a problem with my main yard track or if you prefer my inbound/outbound track. The problem is this. When I run my engines in the forward positions as if they were coming into the yard, they run perfectly. But when I reverse the direction, the engine shutters like the polarity of the track is reversed. I have tested almost all my engines on this section of track and they all do the same thing to some degree. I can't understand why this is happening as this tract is isolated and has it's own power source. I have check and rechecked this section and I can find nothing wrong and it's the only section of track throughout my whole layout where I have this problem. It's a section of track about 5 ft. in length. Anyone with an idea please chime in as I have nothing left to explore.
May we assume it's DC, as it's hard to fit Z with DCC? Have you connected this power source to other blocks, or other power sources to this track?
Mathew, Welcome. Sorry to read about your problems. We really need a bit for info to provide specific advice. What type of track/turnouts are you using/ Which types of locomotives? How What type of throttle are you using? If there is polarity I wouldn't expect the locomotive to shutter. Mark
I'm using Marklin track with Marklin Turnouts. It is DC. This track is isolated from the main line at both ends of the yard and I have connected this pack to other blocks and the main line. No problems. I am using an MRC Tech 7 the older model. I have a variety of locos, MTL and ACL from Geeps to SD75's and a couple of ES44's. I have checked all connections and yet I am unable to ascertain the problem. This is the only section of track that causes grief. It seemed to work fine when I tested all the yard tracks soon after installation. I can't tell if the problem in on one side or both rails. It's got me stumped.
Do you use the power pack's reversing switch to change direction, or an external switch? Is that power pack specific to only that piece of track, or does it power any other part of the yard?
MRC Tech 7 ? ? ? WOW that is way way too powerful for Z scale use if memory serves me correctly they put out 23V DC or 24V DC MTL locos only need 8V DC to 10V DC Early AZL Geeps had 8 volt faulhaber motors. Newer AZL loco's have 12V DC motors. But no Z scale Loco that im aware of can handle 23V DC. Overpowering a Z scale loco will burn out the motor. Stop using the MRC Tech 7 and buy a Z scale power supply. David
No its not Z scale has had drop in decoders for years now. You simply lift the body off slide out the factory board slide the decoder back in its place put the body back on and your done. David
I've been using MRC transformers for years and never yet had a problem. I had a small pack with my first Z scale Marklin set 15 years ago, but someone once told me that MRC's are the best in the business. So I switched an never looked back.
The reason I say it appears as if there is a change in polarity in the track is the way the engines behave when I reverse them. They shake, and shutter and hesitate when in reverse mode. I only ever had this problem once before years ago when I dabble in HO. I had a reversing loop and if the polarity wasn't changed by a separate toggle switch, the train or engine would shutter when it came to the isolation block which was just before the turnout and would behave like it was tying to proceed but was being held back because the flow wasn't in the proper direction. So I'd move the toggle and change the turnout and off the engine would go. I've examined this stretch of track and can find nothing that would cause this to happen. Even my Marklin engine is affected. I just don't understand it.
That seems to eliminate the power pack as the problem, though you can be 100% sure if you connect a different pack to that track and get the same result. Clearly it isn't a simple short as the symptoms would be different, and would happen even when the polarity is reversed. It being a lead track to the yard, it must have turnouts in it. Are those properly insulated from the other yard tracks?
Just for curiosity sake I did connect a different power pack to track and I got the same thing. Yes there are 7 turnouts on this track but all are isolated and their tracks are controlled again by a separate power source. To clarify, All the tracks that run off the main track are individually powered through a series of toggle switches which get their power from an independent power source. I'm wondering if perhaps I should rip up this section and re-lay it after inspection.
Märklin turnouts are pre-isolated so do not need isolating with the yard (make up those crazy turnout yards) but must be isolated across both rails if multiple power packs are used (i.e. Main and yard tracks). You mention at the ends of the yard, so the yard itself, with its own power pack, should be abe to run every where. But I suspect 1 Main rail (or other internal adjacent line) is not isolated so, when switching polarity, you run into that juncture. But this should not happen within the yard (between turnouts). This happens *exactly* where on the turnout? when it reaches the Frog? Joint between the turnout and next track? This happens anywhere or just a single turnout? So grab a volt meter and probe from 1 rail of the turnout (i.e. the outer Stock rail) and the other rails. Then, switch the polarity and probe again, especially where the first axle touches . . . ? Can you post a photo or sketch of this?
Or an ohm meter between that track and rails in the yard, to ensure they really are properly insulated from each other.
Is the track new or used? Try swapping with a known good turnout and see if the problem follows a specific turnout.
Ok, I need to clarify again. The turnouts themselves are not isolated. Only the tracks going to a particular siding are isolated and power to each is controlled by a toggle switch which in turn gets it's power from the power pack. All turnouts are joined together and all get their power from a single isolated power source. If you think of a ladder type of yard with all the turnouts connected together in a single line and each track that branches off of these turnouts is isolated and powered by a toggle. At the time of installation all the track and turnouts were new. I can't send photos because I don't have a camera or computer program for photos. I'm going to tear up this section of track and put down different track but this time I'm going to inspect the ends to make sure they can join properly. Don't know if that will solve the problem but I have to do something.
Get a meter and find the problem. That qualifies as doing something. Working harder can fix it if you're lucky. Working smarter fixes it every time. Do the yard tracks have one insulated rail or both? This only happens in one direction. How can a short only happen when the direction switch is in a particular position? It can't. But if power pack A and power pack B are connected together through some errant track or wiring, they can get along when they're both pumping + into the left rail and - into the right. But throw the direction switch on one and they won't get along at all. Does this problem only happen when more than one power pack is powered up?
There are 2 packs in play here. One powers the sidings and the other the main or approach line. Each is dedicated to one particular function such as the approach line or the sidings. There is no way they can interfere with each other.
There is interference. Therefore... Have you checked every wire? Every connection to every toggle switch? Every wayward dribble of solder? Every little white metal detail part that fell off a car undetected? It's a model railroad. There are a thousand ways they could interfere with each other.
