MRC-loco runaways : LUSENET : Wiring for DCC : One Thread

Command 2000: I have experienced loco runaways using MRC Command 2000 with MRC PowerStation-8 booster and MRC Walkaround throttle in use. If the Walkaround is unplugged while a train is running, the loco will runaway when the remote throttle is plugged back into the same recepticle. This occurs using the standard Walkaround cable plugged directly into the Command 2000 unit or using an extension wired into my layout. Runaways do not occur if (1) the booster is removed from the circuit or (2) the remote throttle is turned OFF on the Command 2000 and throttles #7, #8, #9, #10 are used. My layout is 75 ft. point-to-point with proper bus and feeder wiring for DCC.

All 5 locos have MRC 310 decoders. Even using an 8 ft. test track not connected to the layout, loco speeds will change noticeably whenever the Walkaround throttle is ON (Set 1). Also, locos programmed for Walkaround use will creep very slightly when all throttles are OFF.

All my equipment, including a locomotive, is at MRC after their first tests of my Command 2000 and Walkaround throttle found no problems. Any ideas?

Steve Miller

-- Steve Miller (, March 15, 2002


Follow up status: March 22 2002: MRC could not reproduce this problem at their facility. Equipment being returned.

Steve Miller

-- Steve Miller (, March 22, 2002.

Update: Runaway condition is repeatable using the following steps: With train being controlled by MRC Walkaround throttle, programmed for train #7 (Walkaround throttle #4):

1. Set speed on Walkaround throttel slow (third line on slide) 2. Unplug throttle 3. Replug throttle 4. Change speed (1 line either way) 5. Unplug throttle 6. Train will runaway after about 1 second 7. Train control is restored if throttle is plugged back in

All electrical grounds have been checked and MRC equipment verified. Sources of electrical interference are not apparent.

Have you had this problem? It appears to be a design weakness with the Walkaround unit to me.

-- Steve Miller (, March 27, 2002.

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