Installed in Athearn in 10/14. Has maybe 1 1/2 hrs run time. Running it at 1/2 speed, rather spectacular crack sound, stopped dead, on straight track. NCE fault light blinking on. Spectacular electrical failures usually indicate a short. Sdxh encoder had burn spot on power side of board, corner near receptacle vicinity of red/ orange wires. Rewired analog, ran many times around layout. Benched test .9 amps stalling it, about .7 full throttle no load. Lesson 1: Do not glue Sdxh cap down, 2 sided tape from now on. Lesson 2: Returned encoder to NCE, lost receipt and credit card statement no valid, $17.00 replaced. Take better care receipts.
Installed replacement, only wired 4 power leads, left shell off. Set back on DCC powered track enter loc address, idle sounds come up, let sit for bit seem oked. Run another controverted engine on loop, fine. Put back on track bring speed up to 3, puff of smoke, NCE faults, burnt spot same place. Insulation between motor brush clip and frame good. What am I missing?
You didn’t give us your Ahearn model. I agree with David, the current sounds high. My SD40-2s draw .4 amps no load and stall is very close to 1 amp. Working hard my all of my SD40-2s draw about .7 amp each.
Mel
Modeling the early to mid 1950s SP in HO scale since 1951
If it is a blue box, Ready To Roll, or something based on that type of mechanism, the motor is not isolated from the frame and will fry the decoder. There have been a number of how-tos and articles on how to corrrect this.
F45 Burlington RD# 6615. If their was a ground to frame would the NCE not fault when unit set on rail? I did isulate motor from frame, it does not read continity to frame even when moving motor on mount. Is there a circut breaker or product avalibe that can be hook between motor and power that is fast enough to prodect encoder while trying isolate proplem?
When you isolated the bottom motor wiper contacts if you did what I do you compressed the wiper back into the motor strap (for lack of a better word). I had one return back down and touch the frame over time so now I solder the wipers flush to the strap then use a file to insure nothing touches the frame. The general advise is to cut off the wipers, in doing so make sure everything is clear and the strap doesn’t make contact to the motor frame or the locomotive frame.
If you are using the decoder to drive the Athearn headlight make sure it’s also isolated from the locomotive frame, that’s not an easy task using the Athearn mount.
Mel
Modeling the early to mid 1950s SP in HO scale since 1951
This F45 has metal side frames rivrted on trucks. Found without to much tipping and jiggle they wil contact the frame. Will figure some way to coat them.