Attributes . Eaton?s Heavy Duty Fusible Safety Switches offer the ability to manually open and close a circuit and provide over current protection by means of field-installed fuses. Switches are 100% load break and 100% load make rated and are suitable for service entrance use. Fuse pullers are built in on NEMA 4X and NEMA 12 enclosures through 200 amperes. Tangential knockouts on NEMA 1 and NEMA 3R enclosures through 200A. . Names