Lee: Are you running in command mode? The problem only occurs if the ZW-L is set to full voltage and you are running a pulmor motor and the amp reading on the ZW-L is around 6. Can motors do not cause any problems.
No, I run conventionally.
First, I know that because of its chopped waveform outuput - the "volts" reported by the ZW-L's meter are not equal to normally measured volt readings, and that the numerical indications on the throttles are not exactly corresponding to output "voltage." STill, I will refer to both below as voltage.
I have not had this identical problem, but I have had one recurring problem(that is not going to go away) with the ZW-L with Pullmor motored locos. I have it to the largest degree with the Lionel Santa Fe Anniversary passenger set: the A-B-B-A engine set has, I think, four Pullmors, and I've added two incandescent lighted cars to the seven car set. Liberal use of throttle (up to say, 16 or 17) when this train starts out will trip the ZW-L's 10-amp breaker: the "locked rotor" current draw of the Pullmors at, say, throttle level 16, plus the lighting gets me a nasty red over-current light and then trips the breaker in short order. I've learned to ease the throttle up to about 13 "volts" (or whatever the meters are actually reading, which barely gets the motors' attention and just barely moves the train - with a lot of groaning, then to gradually increase throttle now that the rotors are turning a bit. This actually flashes the red over-current warning light for about three seconds but it never trips.
This same train did not cause this same level of heartache with Z4000 I had before. Yes, I could trip the Z4K's 10-amp breaker with a quick start at very high voltage (snapping the throttle to full when the train was standing still), too, but a normal start requiring only about 16 volts which gave its digital current reading to about 9.5 amps and the breaker never got excited about it.
I think the ZW-L's chopped waveform output, while just fantastic for powering can motors slowly and linearly, runs into "linearity" or reactive power issues with the Pullmor motors AC field magnets, etc. I think this causes the ZW-L a bit of heartburn and perhaps to misread its power output slightly. This probably causes more that just heartburn when you run digitally since there, the throttles are advanced to the max
Sorry I can't be of more help.
