Product Description
General
Eaton's Cooper Power™ series ELF™ current-limiting dropout fuse is a full range current-limiting fuse designed for mounting in an industry standard interchangeable cutout that is presently used for expulsion fuses. The ELF fuse is designed to be used to protect pole-type transformers, single-phase and three-phase laterals and underground taps.
The full-range current-limiting rating ensures reliable operation of all over-loads and fault currents. The element construction consists of two separate sections (low-current section and high-current section) which are self-contained in one housing. The low-current section provides consistent, reliable clearing of all currents high enough to melt the element. The high-current section is a punched-hole ribbon design which controls peak arc voltage levels and limits both current and energy (I2t) let-through levels during high-current fault clearing operation.
The ELF dropout fuse operates silently, unlike expulsion fuses. In addition, the expulsive shower that exists with an expulsive fuse operation is eliminated. This offers increased safety to line personnel during circuit energization operations. In addition, the reliable drop open design makes
Production tests
Tests are conducted on 100% of production in accordance with Eaton requirements.
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Physical Inspection
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I2t Testing
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Resistance Testing
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Helium Mass Spectrometer Leak Testing
Installation
The ELF fuse is designed to be mounted in 15 kV and 27 kV, (110 kV, 125 kV or 150 kV BIL) rated interchangeable open distribution cutouts including Eaton's Type L, S&C Type XS, Hubble Type C™ and ABB Type ICX™ cutouts. Designs for use in 35 kV (170 kV BIL) rated ABB Series V™ cutouts are
also available.
It is easy to install using a clampstick due to its small size. Refer to Service Information MN132028EN ELF Current-Limiting Dropout Fuse Installation Instructions for installation instructions.
Table 3.
Recommendations for Distribution Transformers in Single-Phase Applications (Refer to Figure 3 for primary voltage connections, Figures A and D.) †
Fuse Voltage
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