Hi there,you still should totally disconnect the "polarity" sw.What it does is either make the neutral wire,(white) or the hot wire,(black) the hot wire feeding the circuit.This is why you see the fuse on the neutral side not the hot where it would be today.If you wire the white wire directly to one side of the power trans.,and the hot to the power sw.,(I believe it's the middle terminal) and then to the fuse,you can change the fuse safely by shutting off the power sw.The downside to this is even when the fuse blows,the pilot light in the sw. will remain lit,because of it's internal connection to one side of the sw.,which isn't really shown on the schematic.Hope this is of some help,good luck,be careful with the A.C. hookup,Mel.
