150/250/500/600/700 VAC s Very Fast-Acting s 1 – 1000 Amperes
Voltage Ratings: L15S: 150 V AC/DC (1 – 60A)
150 VAC (70 – 1000A)
100 VDC (70 – 1000A)
L25S: 250 V AC/DC (1 – 200A)
250 VAC (225 – 800A)
200 VDC (225 – 800A)
L50S: 500 VAC/450VDC
L60S: 600 VAC
KLC: 600 VAC
Interrupting Rating: AC: 200,000 rms amperes
(L15S series 100,000 amperes)
DC: 20,000 amperes
Ampere Range: 1 – 1000 amperes
See Rating Table for ratings available
in each series.
Approvals: UL Recognized under the Components Program
and CSA Recognized under the Component
UL File No: E71611
CSA File No: LR29862
L15S and L25S series fuses are Littelfuse
Certified for DC ratings shown in Rating Table.
See Rating Table.
RECOMMENDED FUSE BLOCKS
LSCR series:Refer to Fuse Block section of this catalog for
Designed to protect today’s equipment and systems,
Littelfuse semiconductor fuses are manufactured with
Littelfuse-developed technology that sets tomorrow’s stan-
dards for accuracy, consistent quality, reliability, and predict-
able performance. By using advanced metallurgical, polymer,
and materials research; mathematical modeling, and comput-
erized statistical analysis; Littelfuse engineers have redefined
Designed specifically for supplementary protection of
semiconducting devices such as silicon controlled rectifiers
(SCR’s), diodes, thyristors, triacs, transistors, and similar
solid-state devices. These devices are used in power
equipment including variable speed drives, power rectifiers,
UPS systems, DC power supplies, and in a wide range of
May be used wherever extremely fast-acting, current-limiting
fuses with no time delay are required.
s 200,000 A.I.R. — Reliable interruption of all overcurrents up
to 200,000 amperes . . . meets present and future system
requirements. (Note: L15S series has 100,000 A.I.R.)
s Extremely Current Limiting — Low I2t and peak let-through
currents meet most semiconductor requirements.
s UL Recognized — Littelfuse semiconductor fuses are
recognized under the components program of Underwriters
Laboratories, Inc., and carry the mark. UL Recognized
semiconductor fuses may be used to provide supplemen-
tary protection in UL listed equipment.
LONGER EQUIPMENT LIFE
s Low Watt Losses — Means less heating and power
consumption in circuit.
s Controlled Transient Overvoltages — All circuits are subject
to transient overvoltages during fault current interruption.
These transient overvoltages (arc voltages) start when fuse
links melt or circuit breaker contacts part, and subside
when circuit is interrupted. Semiconductors are very
sensitive to overvoltages. Littelfuse semiconductor fuse
designs keep transient overvoltages to low levels and help
reduce semiconductor failure.