Ok leave it to ME. I have one BLI P3 SD7 that shorts out the mainline every 3 to 6 feet. No other BLI, Athearn, Atlas, Bachmann or Rapido loco does this. The shorting location changes based on the loco’s last location. Usually NOT on a switch.
I am thinking this may be an inrush current problem. Does it trip the breaker with the sound on the engine muted?
It may be that the breaker is set to trip at too low of a current draw. Depending on which breaker you use, some have an adjustable trip current jumpers. Also, the time delay may be adjustable.
Probably not a bad idea, but before you send it back to BLI, disconnect the main line bus from the circuit breaker and connect it directly to the booster (or indirectly through the terminal block). If the loco performs OK, you may need to adjust a setting on the circuit breaker.
Well I shut the sound and it works fine. Turned sound back on and problem reoccurred.
I knew this loco‘s wheels get dirty so I figured I’d see what happens if I clean them. Turns out even though the wheels looked clean and shiny they were not clean.
The reason I said short was that the Main PSX tripped and the other loco (elsewhere on the layout) shut. The Main came back on and both loco’s came back when the BLI began to run again. Very strange.
It seems they tried that and got the desired proof that it could be inrush after good pickup is restored.
I am always puzzled by the dirty wheels part. I do know that locomotive tires do eventually need to be cleaned, but it is so seldom on my own layout that I usually begin to suspect I need to clean the rails, or clean them in a way other than what I have been doing if I feel I have somehow been maintaining their cleanliness.
This sounds like you need to take an hour or more one early Sunday morning before everyone else has stirred and have at them rails. Use a metal polish, or use isopropyl alcohol, and wipe them carefully, frequently turning the clean cloth. No matter how many times you swipe a spot, you’ll get plenty of discolouration grey on the cloth, so just just a couple of swipes should do it.
What works for me is a part of the ‘gleam’ process. When I know my rail tops are wiped clear of any gunk, I run a large steel washer, rounded rim down, over my rails back and forth with only medium pressure, say 10-15 pounds. Take your time; you want this to work without messing up your rails or your gauge.
There’s no reason your loco tires should be getting covered often, if that seems to be what you’re experiencing, unless your rails have some sort of organic material on them that gets carbonized or caramelized by hot microsparks all the time.
It’s the repeated inrush. With dirty wheels, power is lost, the capacitor drains, wheels make contact again, cap charges up. Instead of getting a current inrush once, when first turning on power, it’s getting one every time the contact is broken and regained.
FWIW The very first BLI loco I bought (PRR T1) (and this was before I switched to DCC) I had intermitant connectivity problems even with clean track. After cleaning the wheels I had no issues.
I’ve seen this on pretty much every new BLI loco I’ve bought. I recently bought a Zephyr set & a couple dozen refurbished P70. Same thing. Interior lights flicker when spanking new out of the box. Clean the wheels no problem. It seems to be very consistent with BLI for some reason.
Capacitor inrush appears like a short, or at least a fairly high overload, depends on what the valus of the capacitor is and what the ESR of it is, but it would typically appear as a very low (few ohms or less) ‘short’
So, it tripped the PSX circuit breaker set at 3.81 amps.
I wonder if it would trip the 5 amp booster?
I gotta say, I have had some seriously dirty loco wheels in my time, a few with a large buildup of crud, and I have never tripped any of my PSX circuit breakers.
I agree, Ive had loco wheels that you could see dirt on and they have stalled (obviously) and when I cleaned them worked fine. But I think there may be more going on here. This loco had TWO bad decoders. The first would just stall randomly and BLI Sent me a new one. The second would have sound come on when the layout was powe3red up no matter what I did to prevent that. I sent it back and BLI replaced the decoder.
I have to wonder if that inrush is not exacerbated by some other electronic or connection flaw.
I only have a total of one BLI diesel on the layout, an SD40-2. It more or less runs fine now, but exhibited a lot of problems with random shutdowns with the original QSI decoder and wiring. I was able to eliminate the frequent stalling only by adding a keep-alive (a Soundtrax Current Keeper). Without the keep-alive it was essentially unusable, regardless of how clean the wheels and axle bearings were. It would stall all over the place, not necessarily on typical culprits like dead frogs.