Zero Awaiting Interrupters - Any device that requires alternating current passing through a zero reference to interrupt a circuit; a general name given to expulsion type fuses (cutout, fuse links, Bay-O-Net links, cartridge fuses.)

Zero Forcing Action Interrupters - A device that does not require the current to pass through a zero reference to interrupt a circuit; any device that inserts a large resistance into the circuit causing a phase angle shift to near unity and the forcing of the system current to zero; a general name given to current-limiting type fuses.