How did I do this? My Hogwarts Express passenger car 99718 started smoking for no apparent reason (I suppose the dementors could have been at their nasty work). I run DCS with old ZW power and 10 amp fuses between track and transformer. Never blew the fuse. I opened the car and found this! Anyone ever had this adventure, or does he-who-must-not-be-named have my number.
Replies sorted oldest to newest
Unless your problem was drawing more than ten amps for a while, the fuse would not open. If you wire in a fuse, inside the rail car, of the appropriate current rating for the lamp strip, and the lamps begin to emit the magic smoke, that fuse will open.
Must be those Slytherin kids at it again...
Actually, that's a classic case of a circuit frying to protect a fuse. Only thing for it is to replace the strip. @gunrunnerjohn makes a lovely board for constant lighting of LEDs for just such an application; drop him a note.
Mitch
Was the car derailed? Have seen where you can do a lot of welding with a 10 amp fuse before it blows.
Sounds like a partial derailment. A 10A slow blow fuse will allow the insulation on a small wire or circuit board trace to melt in a matter of seconds. Ask me how I know.
With my PW ZWs I've started using AirPax Instant breakers to prevent this type of issue.
Just as an example, 26 awg is rated for 2 amps. It will melt before it ever gets to 10 amps to blow the fuse. The breakers that @SteveH cites trip instantly if I short a 26 awg wire.
"Sounds like a partial derailment. Ask me how I know."
I think that we need to ask you how a short circuit at the track, and therefore between the track and the transformer, would cause a device beyond the short to burn. The short circuit, by definition, is a short route of travel for the electricity that prevents all or most of the supply voltage from reaching the load. In a track derailment, the load (lighting board) would receive less, not more, power that it would normally receive.
I suspect that like some cars, the two pickup rollers may be wired through the lighting strip. If one lands on an outside rail, you get smoke.
Yep, that's how it can happen. Same sort of thing can happen to an end to end common wire if one of the outside wheels comes to rest on the middle rail.