Protistor® fuse with fast-acting aR characteristic, rated for 350A at 1250VAC IEC and 1300VAC UL, featuring integrated striker indication and open slot blades for bolted mounting.
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Why Choose the Mersen C300612 High-Speed Semiconductor Fuse?
The Mersen C300612 is a premium Protistor® Size 71 high-speed semiconductor fuse designed to provide outstanding protection for sensitive power electronic components in demanding industrial applications. As part of the trusted Mersen Protistor® Size 71 aR series, it delivers ultra-fast fault interruption to safeguard IGBTs, thyristors, diodes and other semiconductor devices from destructive short-circuit currents.
Engineered specifically for modern power conversion equipment, the C300612 features precision die-cut fuse elements embedded in solidified sand to achieve exceptionally low let-through energy and high interrupting capacity. Silver-plated contact surfaces and non-magnetic hardware ensure dependable long-term performance in harsh industrial environments.
With a 350 A current rating, 1250 V AC IEC / 1300 V AC UL voltage rating and open slot blade terminals with an integrated striker, the Mersen C300612 is ideally suited for variable frequency drives, UPS systems, industrial inverters and renewable energy converters where reliable semiconductor protection is essential.
Key Advantages
Ultra-fast aR semiconductor fuse for protecting power electronic equipment.
350 A current rating for demanding industrial applications.
1250 V AC IEC / 1300 V AC UL voltage rating.
Very low let-through energy helps minimise semiconductor damage.
Integrated striker indicator for maintenance and remote monitoring.
High interrupting capacity suitable for modern power conversion systems.
Key Features
Mersen Protistor® Size 71 aR series.
350 A rated current.
1250 V AC IEC / 1300 V AC UL rated voltage.
Ultra-fast aR operating characteristic.
Open slot blade terminals (EF style).
Integrated striker indication.
Silver-plated contact surfaces.
Designed for protecting IGBTs, SCRs, thyristors and power semiconductor modules.
Technical Specifications
Manufacturer: Mersen
Series: Protistor® Size 71 aR
Model: C300612
Catalogue number: PC71UD13C350EF
Product type: High-speed semiconductor fuse
Rated current: 350 A
Rated voltage (IEC): 1250 V AC
Rated voltage (UL): 1300 V AC
Current type: AC
Fuse characteristic: aR ultra-fast acting
Breaking capacity: 126 kA AC
Terminal type: Open slot blade terminals (EF style)
Indicator: Striker
Weight: Approx. 0.54 kg
RoHS compliant: Yes
Reliable Protection for Industrial Power Electronics
High-speed semiconductor fuses are engineered to protect valuable power electronic components by rapidly interrupting fault currents before they can damage sensitive devices. Their low I²t performance reduces thermal stress on semiconductor assemblies, improving equipment reliability while reducing costly downtime.
The Mersen Protistor® range is widely specified by OEMs and industrial engineers for protecting variable frequency drives, industrial motor drives, UPS installations, renewable energy converters and other high-performance power conversion equipment.
Typical Applications
Variable frequency drives (VFDs).
Industrial motor drives.
Power converters and inverters.
UPS and backup power systems.
Renewable energy converters.
Protection of IGBT, SCR and diode modules.
Technical Specifications
Item number
C300612
Catalogue No
PC71UD13C350EF
Description
Square Body High-Speed Fuse Protistor® Size 71 aR 1250VAC IEC 1300VAC UL 350A With Striker Open Slot Blades
EAN/UPC Code
3605340330977
Rated voltage AC UL
1300 V
Rated voltage AC IEC
1250 V
Ampere Rating
350 A
AC or DC
AC
Speed/Characteristic
aR
Fuse Size
71
Mounting
Bolted
Clearing I2t At Rated Voltage
178 kA²s
Melting I2t
22 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
Open Slot Blades
Product Width
51 mm
Product Length
149.4 mm
Product Height
56.5 mm
Sell Pack Quantity
3 EA
Sell Pack Weight
1.62 kg
Sell Pack Width
140 mm
Sell Pack Length
174 mm
Sell Pack Height
71 mm
Product group
Semiconductor Protection Fuses
Body/Insulating Material
Ceramic
Product Weight
0.54 kg
Power Dissipation at Rated Current Value
80 W
HS Code
85351000
Frequently Asked Questions
What is the Mersen C300612 used for?
The C300612 is a high-speed semiconductor fuse designed to protect IGBTs, thyristors, diodes and other power electronic components against short-circuit faults.
What is the current rating of this fuse?
The fuse has a 350 A current rating.
What voltage is the fuse rated for?
It is rated for 1250 V AC (IEC) and 1300 V AC (UL).
What type of terminals does the fuse use?
The Mersen C300612 is supplied with open slot blade terminals (EF style) for secure installation in compatible fuse assemblies.
Does the fuse include an indicator?
Yes. The fuse incorporates an integrated striker indicator that can be used for visual or remote indication when installed with suitable accessories.
Trusted for Semiconductor Protection Worldwide
Mersen Protistor® semiconductor fuses are trusted by OEMs, machine builders and industrial engineers worldwide for delivering dependable protection of critical power electronic equipment.
Item number
C300612
Catalogue No
PC71UD13C350EF
Description
Square Body High-Speed Fuse Protistor® Size 71 aR 1250VAC IEC 1300VAC UL 350A With Striker Open Slot Blades
EAN/UPC Code
3605340330977
Rated voltage AC UL
1300 V
Rated voltage AC IEC
1250 V
Ampere Rating
350 A
AC or DC
AC
Speed/Characteristic
aR
Fuse Size
71
Mounting
Bolted
Clearing I2t At Rated Voltage
178 kA²s
Melting I2t
22 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
Open Slot Blades
Product Width
51 mm
Product Length
149.4 mm
Product Height
56.5 mm
Sell Pack Quantity
3 EA
Sell Pack Weight
1.62 kg
Sell Pack Width
140 mm
Sell Pack Length
174 mm
Sell Pack Height
71 mm
Product group
Semiconductor Protection Fuses
Body/Insulating Material
Ceramic
Product Weight
0.54 kg
Power Dissipation at Rated Current Value
80 W
HS Code
85351000
No documents available for this product.
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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...