I'm a long time user of NCE DCC gear and a big fan of their robustness and relative simplicity. On my railroad (2200') I operate with a 10 amp radio PowerPro (radio) system. Initially I had a single 10 amp booster, as operations intensified over time I added 3 more boosters (now 4 power districts )each with its own fast acting PSX circuit breaker. Later still I purchased a NCE PowerCab for the purpose of testing and configuring locomotives on a workbench roller stand. Soon after I shipped the PowerCab back to NCE for a $90 radio upgrade. With the upgrade the PowerCab functions just like all my other my other radio ProCabs on the railroad during operating sessions, while retaining the capability to run as a self contained "plug-in" DCC system on the workbench..
To answer the question in the post above I unplugged the NCE 10 amp boosters from the layout and clip leaded the output of the PowerCab to one of the power districts. For the test I ran a AtlasO EMD switcher (Tsunami2 2200 2 amp sound decoder) pulling a 16 car freight. The cars were a mix of brass and plastic models weighted to around 16 oz. The PowerCab easily ran the train back and forth within the power district. Then I remembered a neat feature of the PowerCab that I hadn't used in some time. With a couple of button clicks I was able to set up the PowerCab to display real time current draw. I then reran the test train. During the runs the peak current draw shown on the display was 1.1 amp - well within the 2.5 amp rating of the PowerCab. The peak readings were very brief and occurred only when the train first started to move. When rolling down the main the draw was under .6 amp.
IMO a PowerCab is a great way to start out on a modest sized O scale layout - and if later you want to run a couple of relatively efficient multiple unit diesels it can be upgraded to a 5 amp system.
