MERSEN FUSE 250V 5ST 1,25A 5.20 MI5ST25V1,25

MERSEN FUSE 250V 5ST 1,25A 5.20 MI5ST25V1,25

Mersen S090544 MI5ST25V1.25/1000 time-delay 5 x 20 mm glass miniature fuse rated at 1.25 A and 250 V AC with a 100 A breaking capacity.

SKU: S090544Alt SKU: MI5ST25V1,25MPN: S090544
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Why Choose the Mersen S090544 5 x 20 mm Time-Delay Miniature Fuse?

The Mersen S090544 is a compact and dependable 5 x 20 mm time-delay miniature fuse designed to protect electrical distribution circuits and industrial equipment against sustained overloads and short-circuit currents. Part of the established Mersen 5ST IEC miniature fuse series, it provides reliable circuit protection while tolerating the brief current surges associated with normal equipment start-up.

Its time-delay characteristic allows the S090544 to withstand short-duration inrush currents produced by motors, transformers, power supplies and other inductive or capacitive loads. This helps reduce nuisance fuse operation while ensuring that prolonged excessive current is safely interrupted before it can cause significant damage to wiring or connected equipment.

Rated at 1.25 A and 250 V AC, the Mersen S090544 features a glass body and standard cylindrical dimensions for straightforward installation in compatible 5 x 20 mm fuse clips and holders. It is well suited to industrial control panels, automation equipment, power supplies and OEM electrical assemblies.

Key Advantages

  • Time-delay characteristic withstands temporary start-up currents.
  • 1.25 A current rating for low-current circuit protection.
  • 250 V AC rated voltage for IEC electrical applications.
  • Compact 5 x 20 mm cylindrical fuse format.
  • Helps reduce nuisance fuse operation caused by brief inrush currents.
  • Manufactured by Mersen for dependable electrical protection.

Key Features

  • Mersen 5ST IEC miniature fuse series.
  • 1.25 A rated current.
  • 250 V AC rated voltage.
  • Time-delay operating characteristic.
  • 100 A AC breaking capacity.
  • 12.2 A²s melting I²t.
  • Glass body construction.
  • RoHS-compliant design.

Reliable Protection for Circuits with Inrush Current

Time-delay miniature fuses are designed to tolerate brief current peaks that occur when motors, transformers, power supplies and other electrical loads are energised. These temporary surges are often part of normal operation and could cause unnecessary interruption if a quick-acting fuse were installed.

The Mersen S090544 provides a controlled delay during acceptable short-duration surges while disconnecting the circuit when excessive current persists. This balance helps protect connected equipment, improve operational reliability and reduce unnecessary maintenance.

Typical Applications

  • Industrial control panels.
  • Motor control circuits.
  • Electronic power supplies.
  • Control transformers.
  • Automation equipment.
  • Instrumentation systems.
  • OEM machinery.
  • Electrical distribution circuits.

Technical Specifications

Current 25 A
Voltage 250 V
Manufacturer Mersen
Series 5ST IEC Miniature Fuses
Model S090544
Catalogue number MI5ST25V1.25/1000
Product type Time-delay miniature fuse
Fuse size 5 x 20 mm
Rated current 1.25 A
Rated voltage 250 V AC
Current type AC
Operating characteristic Time delay
Breaking capacity 100 A AC
Melting I²t 12.2 A²s
Power dissipation at rated current 0.23 W
Body material Glass
Product diameter 5 mm
Product length 20 mm
Mounting type Clip mounting
Product weight approx. 1.2 g
RoHS compliant Yes
EAN 3605340091847
Device Type Fuse link
Fuse Type Miniature
Fuse Size 5x20 mm
Fuse Class Time delay

Frequently Asked Questions

What is the Mersen S090544 used for?

The Mersen S090544 provides time-delay overcurrent and short-circuit protection for electrical distribution circuits, industrial equipment and electronic systems.

What is the current rating of this fuse?

The S090544 has a rated current of 1.25 A.

What voltage is the Mersen S090544 rated for?

This miniature fuse is rated for operation at up to 250 V AC.

Is the S090544 a slow-blow fuse?

Yes. It has a time-delay characteristic that allows temporary inrush currents while protecting against sustained overloads and short circuits.

Which fuse holder is required?

The S090544 should be installed in a compatible fuse holder or clip designed for standard 5 x 20 mm cylindrical fuses.

Trusted by Electrical Professionals Worldwide

Mersen miniature fuses are widely used by panel builders, equipment manufacturers and maintenance engineers to provide dependable, standards-compliant circuit protection across industrial and commercial applications.

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