RailPro User Group

RailPro => RailPro Specific Help & Discussion => Topic started by: ON28 on July 13, 2020, 03:32:41 PM

Title: LM3-S voltage issues, then motor overload -- why?
Post by: ON28 on July 13, 2020, 03:32:41 PM

Today ran my trusty Atlas GP-7 with an LM3-S and KA-3, when voltage suddenly decreased, eventually down to 3 and change, so I shut down. Found a screwdriver partially on the rails, though the PSX circuit breaker did not trip. Restarted and the loco ran a bit, but again showed fluctuating voltage up and down, then to 3 and change again. I tried auto-resetting max motor current (530 Mah) and it reset to 630. Tried to run and got a Motor Overload alert. I ran other locos and had no problem, though this same situation weeks earlier occurred with a Kato F3/LM3/KA4 after it ran on underpowered track, which I have yet to fully investigate. Any suggestions here? Are my modules damaged, or can they be reset? Thanks!

Title: Re: LM3-S voltage issues, then motor overload -- why?
Post by: William Brillinger on July 13, 2020, 07:00:51 PM

Can you take the KA out and try it again?

Title: Re: LM3-S voltage issues, then motor overload -- why?
Post by: Alan on July 13, 2020, 07:10:45 PM

Also put a voltmeter across the rails near the loco when it is running correctly and again when it is running incorrectly. Reading same voltage as shown on LM both times?

Title: Re: LM3-S voltage issues, then motor overload -- why?
Post by: ON28 on July 13, 2020, 09:25:58 PM

Turns out a quick look under the hood revealed one wire to the KA had come unsoldered. Fixed it, and added heat shrink to secure. The auto-test set voltage at 550 ma and the unit was released back into revenue service! Thanks to all for the help!