I did search the archives before posting, and didn’t come up with anything, so here goes: I set up my small two loop Christmas layout over the weekend, consisting of a 726 on one loop and a 2343 with illuminated cars on the other loop. After about ten minutes with both of them running, the ZW breaker will trip. The brushplate on the 726 gets very warm, but all my brushplates on this style loco do. I swapped it out for another 726, and same results. The pickup rollers on both the 2343 and 726 are cool to the touch. I can, however, run one train for an unlimited amount of time. I serviced all engines recently, so that shouldn’t be an issue. Seems to me that the ZW should have no problems running these. Is it possible that the breaker is getting weak? Thoughts appreciated.
John, Yes it is. I just had to have one of the old style bakealight breakers in a ZW replaced with a new style one. Are you sure none of the cars has a short? Does the transformer get hot when your running both trains?
I had mine replaced with one like this. Works fine now.
It’s time to replace that breaker. The early “black box” type that mounts to the bottom of the case, as well as the later type that mounts to the coil bracket are available as reproductions.
Just went through the same thing with TWO ZW’s… replaced breakers in both and no more troubles. Running multiple trains, lights, switches and more. For the cost of a breaker well worth it.
After replacing the breaker inside the transformer you should consider going with external circuit breakers for each A to D terminal output. The breaker inside mainly protects the transformer from overload, not your trains. If you run newer items with the older ZW it may fry your circuit board, so use a TVS or transient voltage supressor, you can buy them from Mouser Electronics very cheap.
John, I agree TVS transient voltage suppressors are needed for all modern units with solid state electronics. I have then across my transformer terminals but the closer to the engines electronics the better. So I also have them at the lockons and you can install them inside your modern engines too. That is the best place.
