High-speed semiconductor protection fuse with ceramic body, flush striker indication, and metric thread terminals, rated 550A at up to 1300VAC.
£224.26
The Mersen P300508 is a premium Protistor® Size 73 high-speed semiconductor fuse designed to provide ultra-fast protection for sensitive power electronic equipment. Engineered for demanding industrial applications, it safeguards diodes, thyristors, IGBTs and other semiconductor devices against damaging short-circuit and overcurrent conditions while helping maximise system reliability and minimise downtime.
As part of the advanced Mersen Protistor® Size 73 series, the P300508 delivers high interrupting capacity with exceptionally low let-through energy. Its square ceramic body, silver-plated contacts and integrated striker indicator make it an excellent choice for variable speed drives, power converters, UPS systems, renewable energy equipment and industrial automation applications.
Rated at 550 A with a 1250 V AC IEC / 1300 V AC UL voltage rating, the P300508 features flush ends with metric threaded terminals for secure installation in high-power industrial electrical systems requiring dependable semiconductor protection.
High-speed semiconductor fuses are specifically designed to interrupt fault currents before expensive power electronic components can be damaged. The Mersen Protistor® range offers low I²t values and rapid fault clearance, helping extend equipment life while reducing maintenance costs and production downtime.
The P300508 is widely specified for protecting high-power converters, industrial drives, renewable energy systems, UPS installations and other demanding power conversion equipment operating at elevated voltages.
| Item number | P300508 |
|---|---|
| Catalogue No | PC73UD13C550TF |
| Description | Square Body High-Speed Fuse Protistor® Size 73 aR 1250VAC IEC 1300VAC UL 550A With Striker Flush ends metric threads |
| EAN/UPC Code | 3605340329520 |
| Rated voltage AC UL | 1300 V |
| Rated voltage AC IEC | 1250 V |
| Ampere Rating | 550 A |
| AC or DC | AC |
| Speed/Characteristic | aR |
| Fuse Size | 73 |
| Mounting | Bolted |
| Clearing I2t At Rated Voltage | 465 kA²s |
| Melting I2t | 57 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 | 73 mm |
| Product Length | 74 mm |
| Product Height | 78.5 mm |
| Sell Pack Quantity | 1 EA |
| Sell Pack Weight | 1.22 kg |
| Sell Pack Width | 110 mm |
| Sell Pack Length | 125 mm |
| Sell Pack Height | 75 mm |
| Product group | Semiconductor Protection Fuses |
| Body/Insulating Material | Ceramic |
| Product Weight | 1.22 kg |
| Power Dissipation at Rated Current Value | 116 W |
| HS Code | 85351000 |
The P300508 is an ultra-fast semiconductor fuse designed to protect IGBTs, thyristors, diodes and other power semiconductor devices from overcurrent and short-circuit faults.
The fuse has a 550 A continuous current rating.
The P300508 is rated for 1250 V AC (IEC) and 1300 V AC (UL).
Yes. The fuse incorporates an integrated striker indicator that can operate a compatible microswitch for simplified maintenance and fault indication.
It is commonly installed in high-power variable speed drives, converters, UPS systems, renewable energy equipment and industrial power electronic installations.
Mersen Protistor® semiconductor fuses are trusted by OEMs, electrical engineers and industrial maintenance teams to provide dependable protection for high-value power electronic equipment operating in demanding industrial environments.
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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...