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Class T Fuses

JLLS Series

Littelfuse.com/JLLS

©2022 Littelfuse, Inc.

Specifications are subject to change without notice.

Revised: 07/14/2022

Description

The JLLS series fast-acting fuses are the most compact fuses available in ratings above 30 amperes — less than

one-third the size of comparable Class R fuses. The JLLS fuses are used for short-circuit protection of drives and surge-

sensitive components. When rated in accordance with the NEC, these fuses provide fast-acting overload and short-circuit

protection for non-inductive circuits and equipment. Main switches containing JLLS fuses can be used to provide

compact protection for meter stacks. It should be noted that molded case circuit breaker load centers and panelboards

have increased interrupting ratings when “series rated” with Littelfuse Class T fuses. JLLS fuses are available in

non-plated and silver plated terminations.

Features & Benefits

FEATURES

BENEFITS

200,000 AIR

Safety feature providing reliable interruption of all overcurrents

up to 200,000 A

Current-limiting

Reduces damage caused by heating and magnetic effects of short-

circuit currents; extends the equipment’s lifecycle

Fast-acting

Provides fast short-circuit response for equipment requiring fast

overload protection

POWR-GARD® technology

Ensures quality overcurrent protection

Compact size

More efficient use of available space – typical three-pole Class T

fuse blocks require less than 50% of the panel area required for

Class R fuse blocks

Functional protection

When used as input or output fuses for surge-sensitive components,

they can prevent opening of expensive semiconductor fuses that

protect individual components

Applications

• Variable speed drives

• Power conversion devices (inverters, rectifiers, UPS)

• Power supplies and power distribution units

• Compact main switches

• Individual electric services and meters

600 V ac • Fast-Acting • 1–1200 A