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MERSEN Fuse: Class L, A4BY Series, Bolt-On Body, Time-Delay, 300 A, 600 V AC - Time-Delay Bolt-On Fuses
MERSENTime-Delay Bolt-On Fuses

MERSEN Fuse: Class L, A4BY Series, Bolt-On Body, Time-Delay, 300 A, 600 V AC

The MERSEN A4BY Series Class L Time-Delay Bolt-On Fuse (MPN A4BY300) is a 300 A, 600 V AC, 300 V DC industrial fuse. It features a bolt-on body and time-delay operation for overcurrent protection.

SKU 3G-OTH-27088

Brand
MERSEN
Item
Fuse: Class L, A4BY Series, Bolt-On Body, Time-Delay, 300 A, 600 V AC
Category
Time-Delay Bolt-On Fuses
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Local availability & support — Singapore

Local office
20 Woodlands Link #09-05, Singapore 738733
Phone
+65 8878 8355
Delivery
Same-day or next-business-day delivery within Singapore for in-stock items; 7–14 days for factory-order parts from Europe.
Payment
Invoicing in SGD. PayNow, bank transfer, and corporate PO accepted.
Ships to
Singapore

Technical Specifications

MERSEN
Manufacturer Part Number
A4BY300
Series
A4BY
Type
A4BY Series, Bolt-On Body, Time-Delay, 300 A
AC
600 V
DC
300 V

Technical Documents

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MERSEN Products
3G Electric (S) Pte. Ltd. — Singapore

Product Description

The MERSEN A4BY Series Class L Time-Delay Bolt-On Fuse (MPN A4BY300) is a 300 A, 600 V AC, 300 V DC industrial fuse. It features a bolt-on body and time-delay operation for overcurrent protection.

Frequently Asked Questions

What is the MERSEN A4BY300 fuse used for?

The MERSEN A4BY300 is a Class L time-delay bolt-on fuse used for overcurrent protection in industrial power distribution, motor circuits, and feeder applications. Its 300 A rating and 600 V AC / 300 V DC capability make it suitable for high-current branch circuits and equipment requiring reliable short-circuit and overload protection.

What are the specifications of the MERSEN A4BY300 fuse?

The MERSEN A4BY300 is a Class L, A4BY Series time-delay bolt-on fuse rated 300 A, 600 V AC, and 300 V DC. It features a bolt-on body for secure mounting and time-delay operation to handle inrush currents. The manufacturer part number is A4BY300, and it is designed for industrial overcurrent protection.

Where to buy the MERSEN A4BY300 fuse worldwide?

You can source the MERSEN A4BY300 fuse through 3G Electric, a global industrial equipment distributor. We handle full logistics, customs clearance, and delivery to worldwide destinations. Contact us for availability and lead time; we supply genuine MERSEN A4BY Series fuses to industrial buyers globally.

How to select the correct MERSEN A4BY300 fuse for an application?

To select the correct MERSEN A4BY300 fuse, verify the system voltage does not exceed 600 V AC or 300 V DC, and the continuous load current is below 300 A. Ensure the fuse holder accommodates a Class L bolt-on body. Time-delay fuses are ideal for motor circuits with high inrush; consult the MERSEN A4BY series datasheet for coordination.

Used in

Common applications for MERSEN
Power electronics protection — MERSEN A70Q series semiconductor fuses in variable frequency drives for motor control.
Surge protection for industrial panels — MERSEN STP480D07 SPDs in three-phase 480V AC distribution boards.
Control circuit overcurrent protection — MERSEN ATM series midget fuses in PLC and instrumentation cabinets.
Power distribution in manufacturing — MERSEN FSPDB4A finger-safe blocks in motor control centers for wire management.
DC bus protection in renewable energy — MERSEN A30QS series fuses in solar inverter DC inputs.
High-voltage semiconductor protection — MERSEN A70Q series fuses in welding equipment power supplies.

MERSEN Products

3G Electric supplies MERSEN time-delay bolt-on fuses. We supply genuine products with in-stock availability on common SKUs, technical documentation, commissioning support, and warranty service — worldwide.

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Compatible alternatives & equivalents

Cross-referenced by specification & description
MERSEN Fuse: Class L, A4BY Series, Bolt-On Body, Time-Delay, 350 A, 600 V AC, 300 V DC (MPN A4BY350)
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MERSEN Fuse: Class L, A4BY Series, Bolt-On Body, Time-Delay, 350 A, 600 V AC, 300 V DC (MPN A4BY350)
MERSEN Fuse: Class L, A4BY Series, Bolt-On Body, Time-Delay, 200 A, 600 V AC, 300 V DC (MPN A4BY200)
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MERSEN Fuse: Class L, A4BY Series, Bolt-On Body, Time-Delay, 200 A, 600 V AC, 300 V DC (MPN A4BY200)
MERSEN Fuse: Class L, A4BY Series, Bolt-On Body, Time-Delay, 250 A, 600 V AC, 300 V DC (MPN A4BY250)
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MERSEN Fuse: Class L, A4BY Series, Bolt-On Body, Time-Delay, 250 A, 600 V AC, 300 V DC (MPN A4BY250)
MERSEN Fuse: Class L, A4BY Series, Bolt-On Body, Time-Delay, 600 A, 600 V AC, 300 V DC (MPN A4BY600)
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MERSEN Fuse: Class L, A4BY Series, Bolt-On Body, Time-Delay, 600 A, 600 V AC, 300 V DC (MPN A4BY600)
MERSEN Fuse: Class L, A4BY Series, Bolt-On Body, Time-Delay, 400 A, 600 V AC, 300 V DC (MPN A4BY400)
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MERSEN Fuse: Class L, A4BY Series, Bolt-On Body, Time-Delay, 400 A, 600 V AC, 300 V DC (MPN A4BY400)
MERSEN Fuse: Class L, A4BY Series, Bolt-On Body, Time-Delay, 500 A, 600 V AC, 300 V DC (MPN A4BY500)
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MERSEN Fuse: Class L, A4BY Series, Bolt-On Body, Time-Delay, 500 A, 600 V AC, 300 V DC (MPN A4BY500)

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