High-speed Protistor® fuse with 350A rating, 1250VAC IEC and 1300VAC UL rated voltage, featuring a ceramic body, integrated striker indication, and flush ends with metric threads for bolted mounting.
£149.39
The Mersen C300520 is a premium Protistor® square body high-speed semiconductor fuse designed to provide exceptional protection for sensitive power semiconductor devices in industrial power conversion systems. As part of the proven Mersen Protistor® Size 71 aR series, it delivers ultra-fast fault interruption to safeguard IGBTs, thyristors, diodes and other semiconductor components from damaging short-circuit currents.
Engineered for demanding industrial applications, the C300520 combines low let-through energy with high breaking capacity to maximise equipment protection and minimise downtime. Its robust square body construction, silver-plated contacts and solidified sand technology ensure dependable long-term operation in harsh electrical environments.
With a 350 A current rating and 1250 V AC IEC / 1300 V AC UL voltage rating, the Mersen C300520 is ideally suited for variable speed drives, UPS systems, renewable energy converters, industrial rectifiers and power electronic equipment. An integrated striker indicator simplifies maintenance and remote fuse monitoring.
High-speed semiconductor fuses are specifically designed to protect valuable power electronic components from destructive short-circuit faults. Their ultra-fast operation limits fault energy before it reaches sensitive semiconductor devices, helping reduce equipment damage, maintenance costs and production downtime.
The Mersen Protistor® range is widely used by OEMs and industrial engineers to protect variable frequency drives, renewable energy converters, UPS systems, industrial rectifiers and other high-performance power conversion equipment requiring dependable semiconductor protection.
| Item number | C300520 |
|---|---|
| Catalogue No | PC71UD13C350TF |
| Description | Square Body High-Speed Fuse Protistor® Size 71 aR 1250VAC IEC 1300VAC UL 350A With Striker Flush ends metric threads |
| EAN/UPC Code | 3605340329728 |
| 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 Brass |
| Connection/Terminal Type | Flush ends |
| Product Width | 51 mm |
| Product Length | 74 mm |
| Product Height | 56.5 mm |
| Sell Pack Quantity | 3 EA |
| Sell Pack Weight | 1.545 kg |
| Sell Pack Width | 90 mm |
| Sell Pack Length | 170 mm |
| Sell Pack Height | 70 mm |
| Product group | Semiconductor Protection Fuses |
| Body/Insulating Material | Ceramic |
| Product Weight | 0.515 kg |
| Power Dissipation at Rated Current Value | 76 W |
| HS Code | 85351000 |
The C300520 is a high-speed semiconductor fuse designed to protect IGBTs, thyristors, diodes and other power electronic devices from short-circuit faults.
The fuse has a 350 A current rating.
The fuse is rated for 1250 V AC (IEC) and 1300 V AC (UL).
The aR characteristic provides ultra-fast short-circuit protection specifically for semiconductor devices while allowing normal operating currents without nuisance operation.
Yes. The C300520 incorporates an integrated striker indicator for simplified maintenance and remote indication when used with compatible accessories.
Mersen Protistor® semiconductor fuses are trusted by machine builders, panel manufacturers and industrial engineers worldwide for delivering dependable protection of critical power electronic equipment.
● Service Agreements
Credit Accounts
Our service agreements are built to support long term procurement relationships. By working closely with engineering teams and procurement departments, we help streamline purchasing processes while ensuring consistent access to critical components and sourcing support when it matters most.
● frequently asked questions
At Led Controls Ltd we help engineers source the right automation and control gear with confidence. below are quick answers to what we are asked most often.
We supply all leading manfacturers in our industry. we offer next day delivery on most poplour products.
Your content goes here. Edit or remove this text inline or in the module Content settings. You can also style every aspect of this content in the module Design settings and even apply custom CSS to this text in the module Advanced settings.
Your content goes here. Edit or remove this text inline or in the module Content settings. You can also style every aspect of this content in the module Design settings and even apply custom CSS to this text in the module Advanced settings.
Your content goes here. Edit or remove this text inline or in the module Content settings. You can also style every aspect of this content in the module Design settings and even apply custom CSS to this text in the module Advanced settings.
Your content goes here. Edit or remove this text inline or in the module Content settings. You can also style every aspect of this content in the module Design settings and even apply custom CSS to this text in the module Advanced settings.
● latest blog
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...