My spouse has a power converter for mobile work; it's output is 120V AC, for a laptop. When plugged into the "accessory socket" (which routes thru slot/fuse 3, 15 amp), the fuse has blown twice in about 2 months. The power converter unit recommneds "auto fuse, 20 Amp". Is it safe to use a 20 amp fuse in slot 3, if it's only powering this device?