The solid cap of the fuse carrier shall clamp the button head of the fuse link, closing the top end of the fuse and allowing only the downward venting during fault interruption.
For embedded components, the pull out strength should be such as to result in breaking of the porcelain before pull out occurs in a test.The top and bottom assemblies as also the middle clamping hardware shall be either embedded in the porcelain insulator with sulphur cement or suitably clamped in position. The fuse base shall be a bird-proof, single unit porcelain insulator with a creepage distance (to earth) not less than 320 mm.The bottom assembly shall have a lifting eye for the hook stick for removing or replacing the fuse carrier. It shall make smooth contact with the fuse base bottom assembly during closing operation.The fuse carrier bottom assembly shall be made of bronze castings with silver plating at the contact points to efficiently transfer current to fuse base.
Bimetallic conductor pls cadd why and what manual#
The fuse carrier shall be provided with a cast bronze opening eye (pull ring) suitable for operation with a hook stick from the ground level to pull-out or close-in the fuse carrier by manual operation.It shall make a firm contact with the button head of the fuse link and shall provide a protective enclosure to the fuse link to check spreading of arc during fault interruptions.The fuse carrier top contact shall have a solid replaceable cap made from highly conductive, anticorrosive copper alloy and the contact portion shall be silver plated to provide a low resistance current path from the Fuse Base Top Contact to the Fuse Link.
The conducting parts shall be made of high strength highly conductive copper alloy and the contact portion shall be silver plated for corrosion resistance and shall provide a low resistance current path from the bottom fuse carrier contacts to the bottom terminal connector.It shall also prohibit accidental opening of the fuse carrier due to vibrations or impact. The top assembly shall be robust enough to absorb bulk of the forces during the fuse carrier closing and opening operations and shall not over-stress the spring contact. The top assembly shall have an aluminum alloy terminal connector.The contact shall have a socket cavity for latching and holding firmly the fuse carrier until the fault interruption is completed within the fuse.The top current carrying parts shall be made of a highly conductive copper alloy and the contact portion shall be silver plated for corrosion resistance and efficient current flow.Spring washers shall be electro-galvanized. Nuts and bolts shall conform to IS : 1364. All ferrous parts shall be hot dip galvanized in accordance with the latest version of IS : 2632.The cutouts shall be of single vent type (downward) having a front connected fuse carrier suitable for angle mounting.The rated breaking capacity shall be 8 KA (Asymmetrical).Metal parts acting as spring The temperature shall not reach such a value that Elasticity of the metal is changed.Across the isolating distance 32 KV (rms).Rated One Minute Power Frequency Withstand Voltage (Wet & Dry) for Fuse: Across the isolating distance of fuse base 86 KV (Peak).To earth and between poles 75 KV (Peak).Rated Lighting Impulse withstands Voltage for Fuse: The distribution fuse cutouts shall be outdoor, open, drop-out expulsion type fuse cutouts suitable for installation in 50 Hz, 11 KV distribution system.Temperature cycle test on porcelain housing.ġ1 KV DROP-OUT FUSE CUTOUTS: ( IS: 9385 (part-I to III).).Hundred percent 1.2/550 microsecond impulse spark over test.Voltage withstand tests of arrester insulation.Routine Test: Dry Power frequency spark over test.The following routine and type tests as laid down in IS : 3070 (Part-I) shall be carried out.The nominal discharge current rating of the lightning arresters shall be 5 KA.This will be applicable to the effectively earthed 11 KV systems co-efficient of earth not exceeding 80 percent as per IS: 4004 with all the transformer neutrals directly earthed.The rated voltage of lightning arresters shall be 9 KV (rms).J166 Comments 11KV/415V over Head Line’s Specification and Installation (REC): 11KV LIGHTNING ARRESTER (IS : 3070 (Pt-II)).