EKM Metering recommends (and UL requires) that the hot lead voltage reference wires running to the electic meter, be fuse protected with 1 amp fuses. These should be placed inline with with voltage reference wires running from your hot lines to the meter. The fuse holder includes a 1A fuse inside. UL Recognized 250 volt Fuse Holder with 1 amp 250 volt ACC fuse.