It's probably rated at 1.5A because I believe it will intially draw a bunch of current when it is first plugged in as it is is just a big coil (an inductive load) and as the field is built up in the coil the current demand will drop.
Of course I reserve the right to be wrong, it's been a long time since the mid-80's so I may have forgotten how this stuff all works or they may have changed the rules, LOL.
TB
