There were 2 different JEP 220 locomotives (well 3, one was a clockwork version, so that is presumably not the one you have).
The first one was made from 1920-1922 and that was a high voltage locomotive which will not run on a ZW.
The second one (brown with NORD markings) was made between 1935 and 1937. There were different versions with different motors made. I assume also a high voltage version. The version I have runs on a ZW but also on a DC power-supply. Just try carefully whether it runs, but first check whether the wheels turn freely, the carbon brushes and brush plate. JEP motors are robust. I have not found a JEP locomotive that did not run (after a clean).
Regards
Fred
