Engine Stalling

[JGray]

I'm building a first layout. It is N scale. I'm laying track, wiring as I go, and running an engine to see if everything is OK. I am using a Digitrax Zepher with a PSX-3 for sector control. I have laid about 40' of the main line which I am running on the first board of the PSX-3. I have also installed a UP-5 Loconet with UT-4 tethered throttle. My bus wiring is 14 AWG. Feeders are about every 6 feet and are 20 AWG and are from around 6" to around 20" long. I am using 3M suitcase connectors. The track is Peco code 55 with all connections soldered. I am running a Model Power Mikado to test the track. It is DC, so I am operating the Zepher on "00". The track has done well, with no derailments so far. I am however, having occasional stalling of the engine. It does not happen in any particular spot. I have cleaned the track several times. It happens at any speed from a crawl to full blast. The engine will simply stop. When that happens, the track voltage drops to 0 all along the track. It, the voltage, registers 7 at full throtte. Sometimes, the engine will resume running after a few seconds. Always, moving the throttle a tiny amount in either direction will re-start the engine. Other times, the engine will loose speed. When that happens, the track voltage drops to around 2 volts. When the engine stops, the PSX-3 does not show a short circuit D6 LED. At all times, complete stall or slow down, the D12 and D7 LED's remain illuminated. The stalling occurs both with the Zepher base or the UT-4 being used. I am using the DC Mikado for track testing because I am trying to ease my way into this thing. I have some Heritage DCC locos, but am reluctant to do track testing with them for fear of frying something. Any thoughts on what is causing the stalling will be appreciated.

[rrinker]

 That sounds like you have address 00 selected on BOTH the UT4 and Zephyr. When you select the address on the Zephyr, does it display StLo? The two throttles will fight each other, so your loco will be zipping around then it will read the stop setting of the other throttle, and stop the loco. Moving the throttle sends a new command and so it starts moving again.

 When you are done running, always dispatch the address. On the Zephyr console, make sure the speed control is at stop and press Loco then Exit. For the UT4 you have to unplug, hold the Dispatch button, and plug it back in. (see also another reason I won't buy a UT4 - the first being I hate potentiometer controls - with a DT400/402 you wouldn't have this problem of the throttles fighting one another. Yet the operation of the UT4 is based on the majority responses to user polls. Sometimes I wonder about those people on the Digitrax Yahoo group). You can clear everything out of the Zephyr and start fresh by going to the back of the manual and following the procedure for OpSw 36 reset. That will clear any stored loco info from the Zephyr and allow you to start clean. Always dispatch and you won't have the problem come back.

                                             --Randy

 

[Hamltnblue]

 Sounds reasonable for sure.  A quick check would be to remove all but the main throttle and see if things run fine.

[JGray]

Many Thanks Randy. You nailed the problem right on the head. I just tried your advice and it worked great! I ran the Mikado several times up and down the completed section of the main line at maximum and minimum speeds and it did not skip a beat. Its really great that MR provides this forum and that people like you are willing to share expertise with a beginner like me. Thanks again. Jim