Z4000

If the serial number is 0398, it is the first run of transformers.  Some, but not all, had voltage leakage problems (voltmeter will display about 1-2 volts when levers are down).  Not a major problem, but some people shy away from them.  It can be corrected, but you have to add 4 surface mount capacitors to one leg of 4 ICs on the power board (not easy).  Also, the first run uses a sleeve bearing fan (noisy when they fail) and unique boards that may/may not still be available and are not compatible with later runs.

Good information to know, Thanks!

Thanks, this helps a lot! How about Lionel ZW transformers that came with the 2 power bricks?  Are these just as reliable?

The ZW-C (with power bricks) and its pros/cons were recently hashed out over here with the consensus being that the ZW-L provides a better value even at a greater price: https://ogrforum.com/...w-and-2-power-bricks

Thanks, I will check it out!

@Jon G posted:

If the serial number is 0398, it is the first run of transformers.  Some, but not all, had voltage leakage problems (voltmeter will display about 1-2 volts when levers are down).  Not a major problem, but some people shy away from them.  It can be corrected, but you have to add 4 surface mount capacitors to one leg of 4 ICs on the power board (not easy).  Also, the first run uses a sleeve bearing fan (noisy when they fail) and unique boards that may/may not still be available and are not compatible with later runs.

Great info.   I bought mine used, will have to check the serial number.

If I recall there is a difference in the Volt Amp ratings of the two main outputs.  The earlier ones had a lower output.

Ron

@C.J. posted:

I found a good deal on a Like new MTH Z4000 transformer from 1998.  Is there any difference between early models and more recent ones?  Looking to upgrade from a MRC pure power and postwar ZW (with a Dallee circuit breaker) since I run a lot of modern TMCC/ Legacy and Proto 2/3 locos.

Truthfully, the MRC Pure Power is a very nice transformer, not sure why you feel the need to replace it.  If you're worried about circuit protection, consider adding the PSX-AC to the outputs, that's the best protection going.

DCC Specialties PSX1-AC 3 and 2 Rail Intelligent Circuit Breaker

Thanks, I definitely was concerned with circuit protection and looking for a more powerful transformer with dual controls.  Would it be safe to use the PSX1 with a postwar ZW?  I also use DCS and TMCC.  The layout I am building will have a double mainline with crossovers. A small yard, and a few sidings.  7' x 20'. What would you use for power? Thanks for your help.

@C.J. posted:

Thanks, I definitely was concerned with circuit protection and looking for a more powerful transformer with dual controls.  Would it be safe to use the PSX1 with a postwar ZW?  I also use DCS and TMCC.  The layout I am building will have a double mainline with crossovers. A small yard, and a few sidings.  7' x 20'. What would you use for power? Thanks for your help.

If you already have a PW ZW, that will work nicely, it just needs faster over current protection than its internal breaker.  The PSX AC would provide very good protection against overloads.  Another less expensive alternative to the PSX AC are Airpax circuit breakers.  Link to more info: Airpax Circuit Breakers

For added protection of the DCS and TMCC locomotives internal electronics, TVS diodes can be combined with circuit breakers on the layout (or in the locomotives).

Thanks! I will look into this. If I can avoid buying an expensive transformer and have more mony for the layout then it is a win!