High-speed aR characteristic fuse with ceramic square body, striker indication system, and plain blade silver-plated copper terminals, rated for 315A and up to 1300VAC.
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Why Choose the Mersen A300840 High-Speed Semiconductor Fuse?
The Mersen A300840 (Catalogue No. PC71UD13C315PA) is a Protistor® Size 71 square-body high-speed semiconductor fuse designed to provide exceptional short-circuit protection for modern power electronic equipment. Rated at 315 A with voltage ratings of 1250 V AC (IEC) and 1300 V AC (UL), it delivers reliable protection for diodes, thyristors, IGBT modules and other sensitive semiconductor devices.
Engineered with Mersen's advanced fuse technology, the A300840 features precision die-cut fuse elements embedded in solidified sand to provide extremely low let-through energy (I²t), rapid fault interruption and excellent current limitation. Silver-plated contact surfaces and non-magnetic hardware further enhance long-term reliability in demanding industrial environments.
The integrated striker mechanism enables remote indication or operation of an optional microswitch, making this fuse ideal for critical power conversion systems where rapid fault signalling is essential.
Key Advantages
Ultra-fast aR semiconductor protection.
315 A current rating.
1250 V AC IEC / 1300 V AC UL voltage ratings.
Integrated striker for remote indication or microswitch operation.
Very low let-through energy (I²t) protects expensive semiconductor devices.
Silver-plated contacts for excellent conductivity and corrosion resistance.
High interrupting capacity for demanding industrial applications.
Key Features
Mersen Protistor® Size 71 semiconductor fuse.
Catalogue number PC71UD13C315PA.
Square-body construction.
aR ultra-fast operating characteristic.
315 A rated current.
1250 V AC IEC / 1300 V AC UL.
Plain blade terminals.
Integrated striker indicator.
Solidified sand arc-quenching technology.
Designed for semiconductor short-circuit protection.
Protected devices: Diodes, thyristors and IGBT modules
Designed for Modern Power Conversion Systems
The Mersen A300840 has been specifically developed for demanding power electronics where conventional fuses cannot provide sufficiently fast protection. Its extremely low I²t characteristic significantly reduces thermal stress on semiconductor components, helping to extend equipment life while minimising downtime following fault conditions.
The integrated striker provides convenient remote indication or can operate an optional field-mounted microswitch, making maintenance and system monitoring more efficient in industrial installations.
Typical Applications
Variable frequency drives (VFDs).
Industrial inverters.
Power converters.
Rectifier systems.
UPS equipment.
Motor drives.
Renewable energy converters.
Industrial automation systems.
Technical Specifications
Item number
A300840
Catalogue No
PC71UD13C315PA
Description
Square Body High-Speed Fuse Protistor® Size 71 aR 1250VAC IEC 1300VAC UL 315A With Striker Plain Blades
EAN/UPC Code
3605340334333
Rated voltage AC UL
1300 V
Rated voltage AC IEC
1250 V
Ampere Rating
315 A
AC or DC
AC
Speed/Characteristic
aR
Fuse Size
71
Mounting
Clip
Clearing I2t At Rated Voltage
129 kA²s
Melting I2t
16 kA²s
AC Max I.R./Breaking Capacity
I1: 126 kA
Indication System
Yes
Indication System Type
Striker
Connection/Terminal Material
Silver-Plated Copper
Connection/Terminal Type
Plain Blades
Product Width
51 mm
Product Length
149.4 mm
Product Height
56.5 mm
Sell Pack Quantity
3 EA
Sell Pack Weight
1.68 kg
Sell Pack Width
140 mm
Sell Pack Length
170 mm
Sell Pack Height
70 mm
Product group
Semiconductor Protection Fuses
Body/Insulating Material
Ceramic
Product Weight
0.56 kg
Power Dissipation at Rated Current Value
76 W
HS Code
85351000
Frequently Asked Questions
What is the Mersen A300840 used for?
It provides ultra-fast short-circuit protection for semiconductor devices including IGBTs, thyristors and diodes used in industrial power electronic equipment.
What is the rated current of the A300840?
The Mersen A300840 has a rated current of 315 A.
What voltage is the A300840 rated for?
The fuse is rated at 1250 V AC (IEC) and 1300 V AC (UL).
What does the integrated striker do?
The striker provides mechanical indication when the fuse operates and can also actuate an optional microswitch for remote monitoring.
What does the aR classification mean?
aR indicates an ultra-fast semiconductor protection fuse designed specifically for short-circuit protection rather than overload protection.
Trusted by Power Electronics Professionals
Mersen Protistor® semiconductor fuses are trusted worldwide by OEMs, panel builders and industrial engineers for protecting critical power electronic equipment in demanding applications.
Item number
A300840
Catalogue No
PC71UD13C315PA
Description
Square Body High-Speed Fuse Protistor® Size 71 aR 1250VAC IEC 1300VAC UL 315A With Striker Plain Blades
EAN/UPC Code
3605340334333
Rated voltage AC UL
1300 V
Rated voltage AC IEC
1250 V
Ampere Rating
315 A
AC or DC
AC
Speed/Characteristic
aR
Fuse Size
71
Mounting
Clip
Clearing I2t At Rated Voltage
129 kA²s
Melting I2t
16 kA²s
AC Max I.R./Breaking Capacity
I1: 126 kA
Indication System
Yes
Indication System Type
Striker
Connection/Terminal Material
Silver-Plated Copper
Connection/Terminal Type
Plain Blades
Product Width
51 mm
Product Length
149.4 mm
Product Height
56.5 mm
Sell Pack Quantity
3 EA
Sell Pack Weight
1.68 kg
Sell Pack Width
140 mm
Sell Pack Length
170 mm
Sell Pack Height
70 mm
Product group
Semiconductor Protection Fuses
Body/Insulating Material
Ceramic
Product Weight
0.56 kg
Power Dissipation at Rated Current Value
76 W
HS Code
85351000
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LED Controls is a specialist distributor of factory automation and industrial controls, supplying OEMs, machine builders, panel builders and end users throughout the UK and worldwide. As a trusted UK distributor for many of the world’s leading automation manufacturers, we provide industrial control products, technical expertise and bespoke automation solutions backed by outstanding customer service.
2025 has been a big year for LED Controls, and our blog has expanded accordingly. We've covered a wide range of topics across industrial control and factory automation this year. From core technology explainers and new product releases to panel building best practice...
2025 has been a big year for LED Controls, and our blog has expanded accordingly. We've covered a wide range of topics across industrial control and factory automation this year. From core technology explainers and new product releases to panel building best practice...