Advice kindly requested regarding older Lionel Powermaster

Are you using a Powermaster cable (6-12893) between the transformer and track? The Powermaster cable has an inline fuse holder in it which will prevent the Powermaster from 'frying'.

The TVS is to protect items on the track from transformer side spikes. The thermal breakers are too slow.

I have found that the Z-1000 trip quickly. But, in your case, it's downstream from the powermaster and then the track. That probably doesn't make it kick.

Put a fuse holder in-line between the track and the powermaster center rail hot wire. (A) Autostore or mail. Find fast-blow fuses. get more than one box. It's an AGC type fuse.

here is some at DigiKey.

If you are running a high current postwar train you may need 7 amp. Like a dual motored F-3 - A-A and lighted passenger cars.

Gentlemen, thank you so much for the prompt information! As I grew up with Postwar, I'm sort of an antique myself, and it's been a bit of a learning curve with today's electronics. Therefore, advice gladly taken, am ordering cable and fuses immediately, as I was using two home-made cables, and wasn't even aware of the Lionel fuse-carrying cables. For a while I was thinking my Milwaukee Road was beginning to resemble the unfortunate real Milwaukee Road in its last days!!!

Great forum here, regards!

Powermasters are relatively cheap on eBay, I believe. I have one that is my main throttle (I use it to put 18V to the track for TMCC), is 20 years old and has yet to even hiccup. (Please! No jinxing!) So, it may be that getting a new one is a good idea. Mine has endured many derailments, and has no additional protection.

Maybe yours is just on the low-end of tolerances.

You raise a good point with the tolerance thing, as I got it off fleaBay for relatively cheap, and it may just be a complete lemon (like my late father's 58 Ford!............. Apologies to Ford owners......). It was also repaired by the previous owner.

Using Atlas 082 track, I have few derailments, just stuff happens when I don't pay attention, but in each case I end up with fried mosfets.

As I use these things only for running older conventional engines for the handheld remote convenience, I wonder if TMCC at a straight 18V is easier on these old boxes than the heavier amperage needed at lower voltages? I don't think these earlier Powermaster have any built-in protective circuitry..............

Anyway, fuses are going in now, per earlier posters' advice.