1、FORD MANUFACTURING STANDARDS ET2 MARCH 1994 FUSE BLOCKS ET2 Page 1 1. GENERAL: 1.1 This Standard describes requirements for fuse blocks or fuse holders to retain dual-element power and control fuses as described in Ford Manufacturing Standard RKl. This Standard does not pertain to devices used to ho
2、ld miniature or glass type fuses. 1.2 Fuse blocks shall have UL 512, “Fuseholders“, listing or recognition and CSA 22.2 No. 39-Ml987 certification as applicable, and shall be correspondingly marked and labeled. 2. METALLIC PARTS: 2.1 Current carrying parts shall be made of copper or copper alloys qu
3、alified per UL 486 and shall be tin or silver plated to prevent corrosion. Brass, copper, or cadmium plating are not acceptable. EXCEPTION: If specified on a plant or divisions Form 2630 - Electrical Equipment Data Form, aluminum alloy may be used for current carrying parts if qualified per UL 486.
4、2.2 Non-current carrying metallic parts shall be adequately plated to resist corrosion. Copper, brass, or cadmium plating are not acceptable. 2.3 Reinforcing springs or wedge type screw clamps shall be furnished on the fuse retainer. Where springs are used, the leaf type is preferred for maximum ret
5、ention. 3. DESIGN: 3.1 The number of joints or surfaces through which current must pass between the fuse and the conductor connected to the terminal shall be minimized. One piece construction shall be furnished on ferrule type clips. Reinforcing springs shall not carry current in either the ferrule
6、or blade type assembly. 3.2 Fuse block base material shall have a UL flammability rating of 94V-1 or better, and a minimum temperature rating of 120 degrees Celsius. 3.3 One, two, and three pole fuse blocks bases for all fuses shall be of single piece construction to minimize alignment and mounting
7、problems. All fuse block bases up through 100 Amperes shall have insulating barriers between the poles 3.4 Terminals shall be suitable for type MTW, 19 strand copper conductors. Pressure plates or saddles are acceptable on fuse blocks rated 30 Amperes maximum. Larger sizes shall be provided with high conductivity box lug terminals per UL 486, with studs or bolts which will accommodate lugs of proper size.
