POWR-GARD® Fuse Datasheet
MEDIUM VOLTAGE FUSES
2,400-38,000 VAC • Current-Limiting
Current-limiting E- and R-rated
fuses are equipped with a
mechanical indicator or striker pin
that protrudes through the fuse
cap upon operation of the fuse.
This provides visual identification
of a blown fuse and can be used
as a trigger for external devices.
Note: Extension distance 1 2” minimum;
/
extension force 2 lb. minimum.
General Information
The terms “Medium Voltage” and “High Voltage” have been
used interchangeably by many people to describe fuses
operating above 600 volts. Technically speaking, medium
voltage fuses are those intended for the voltage range from
2,400 to 38,000 Vac. High voltage fuses are for circuits
carrying voltages greater than 38,000 Vac.
E-rated fuses are considered to be general purpose fuses
and can be used to protect against low and high values
of fault current. R-rated fuses are designed for back-up
protection. They must be used in series with other devices
such as motor overload relays in order to achieve both
overload and short-circuit protection.
Description
Littelfuse® offers a selection of E- and R-rated medium
voltage fuses for the protection of transformers, potential
transformers, feeders, and motor circuits. Single, double,
and triple barrel designs are available to cover a wide range
of current, voltage, and interrupting ratings. Conventional
ferrule type, clip lock, and bolt-in mounting configurations
are available for virtually any application. Hermetically sealed
fuses for use in hazardous environments are also offered.
Medium voltage fuses are not intended to provide overload
protection in the same sense as fuses rated 600 volts or
less. Medium voltage fuse current ratings do not have the
same meanings as the ampere ratings of low voltage fuses.
All medium voltage fuses are limited in their ability to
interrupt low value overcurrents, especially those between
100% and 200% of the fuse’s continuous current rating.
They are designed to carry their rated current without
exceeding the temperature rise permitted by NEMA and
ANSI standards.
Contact the factory or your local Littelfuse representative for
additional fuse ratings or custom mounting configurations.
24-Hour Emergency Service - Call 800-227-0029
Applications
• PowerTransformer Protection
• PotentialTransformer Protection
• Motor Controller Back-up Protection
• Fused Switches
• Feeder Circuits
Bolt-in Mount Fuses
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