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)).