I had two Z4K's for my layout, but they were not quite enough, so I added one ZW-L. Not only did the added ZW-L supply enough power, but the ZW-L's voltage output was much more consistent than the Z4K's. Shortly afterwards, I replaced the two Z4K's with a second ZW-L, and now both ZW-L's run my layout perfectly.
With the Z4K's, which I used for several years, I had to adjust the voltage (handles) depending on the load. With a small load (one engine), setting the handles at 18v worked fine, of course. But as soon as another train entered the block, the voltage would drop to 17v or less. If the train was a double-headed (two A powered units) passenger train (regular incandescent lights in the cars), the the voltage would drop to 16v. So I used to set the voltage at 21v, and it would drop to about 17.5v with the trains.
With the ZW-L's, I set the handles at the maximum; i.e., 18.6v for mine, don't bother them, and the voltage hardly varies. Another thing - the Z4K handles have to be turned down fully when the transformer is shut off before it can be turned on again. Not the ZW-L; leave the handles as you like. This is significant for me because I have the track transformers connected to a remote control outlet so I can turn them on/off remotely, and I do not have to worry about how the ZW-L handles are set.
And that's my 2¢ worth!
Alex (Alexander Müller)
