Standard delivery
£8 ex VAT · free over £200UK parcel delivery is £8 ex VAT, or free on orders over £200 ex VAT.
Heavier items may be charged at a weight-based or pallet rate, shown at checkout.
MERSEN FUSE 6,9 URD 33 D08 A 0800 6,9URD33D08A0800
High-speed Protistor® fuse designed for semiconductor protection with integral striker indication, suitable for up to 800A and 690VAC/700VAC.
£128.30
Why Choose the Mersen L300252 Protistor® High-Speed Fuse?
The Mersen L300252, catalogue number PC33UD69V800A, is a Protistor® Size 33 square body high-speed semiconductor fuse engineered to protect sensitive power electronic equipment against high fault currents. Its ultra-fast aR operating characteristic provides dependable short-circuit protection for IGBTs, thyristors, diodes and other semiconductor devices used in industrial power conversion systems.
Designed for demanding industrial environments, the L300252 combines a high interrupting capacity with low let-through energy to minimise semiconductor damage during fault conditions. The fuse incorporates DIN 80 blade terminals with an integrated striker indicator, allowing optional remote fuse indication via a compatible microswitch.
With an 800 A current rating, 690 V AC IEC and 700 V AC UL voltage ratings, the Mersen L300252 is ideally suited for variable speed drives, UPS systems, converters, renewable energy equipment and other industrial power electronic applications requiring reliable semiconductor protection.
Key Advantages
- Ultra-fast aR semiconductor protection fuse.
- 800 A current rating for demanding industrial applications.
- 690 V AC IEC / 700 V AC UL voltage capability.
- Protects IGBTs, thyristors, diodes and other semiconductor devices.
- Integrated striker indicator for remote status indication.
- High interrupting capacity with low I²t energy.
Key Features
- Mersen Protistor® Size 33 series.
- Catalogue number: PC33UD69V800A.
- 800 A rated current.
- 690 V AC IEC / 700 V AC UL rated voltage.
- aR ultra-fast operating characteristic.
- DIN 80 blade terminals.
- Silver-plated contact surfaces.
- Integrated striker indication.
- Square body bolted construction.
Advanced Semiconductor Protection
Protistor® semiconductor fuses are specifically designed to interrupt extremely high fault currents before they can damage expensive semiconductor devices. Their low let-through energy and rapid fault-clearing characteristics help maximise equipment availability while reducing repair costs in industrial power conversion systems.
The robust square body construction, silver-plated terminals and precision fuse elements provide dependable long-term performance across demanding industrial automation, renewable energy and power conversion applications.
Typical Applications
- Variable speed motor drives.
- Industrial power converters.
- IGBT and thyristor protection.
- UPS and backup power systems.
- Renewable energy inverters.
- Industrial power electronics and automation equipment.
Technical Specifications
Tick the specs you need, then view products that match.
| Fuse Indication | Striker | |
|---|---|---|
| Fuse Type | D / D0 (Neozed/Diazed), Semiconductor | |
| Fuse Class | aR | |
| Voltage | 690 V | |
| Item number | L300252 | |
| Catalogue No | PC33UD69V800A | |
| Description | Square Body High-Speed Fuse Protistor® Size 33 aR 690VAC IEC 700VAC UL 800A With Striker DIN 80 Blades | |
| EAN/UPC Code | 3605340325775 | |
| Rated voltage AC UL | 700 V | |
| Rated voltage AC IEC | 690 V | |
| Ampere Rating | 800 A | |
| RoHS Compliant | Yes | |
| AC or DC | AC | |
| Speed/Characteristic | aR | |
| Fuse Size | 33 | |
| Mounting | Bolted | |
| Clearing I2t At Rated Voltage | 540 kA²s | |
| Melting I2t | 93 kA²s | |
| AC Max I.R./Breaking Capacity | I1: 200 kA | |
| Design Details | Standard Terminal | |
| Indication System | Yes | |
| Indication System Type | Striker | |
| Connection/Terminal Material | Silver-Plated Copper | |
| Connection/Terminal Type | DIN 80 Blades | |
| Product Width | 73 mm | |
| Product Length | 110 mm | |
| Product Height | 78.5 mm | |
| Sell Pack Quantity | 3 EA | |
| Sell Pack Weight | 2.4369 kg | |
| Sell Pack Width | 145 mm | |
| Sell Pack Length | 250 mm | |
| Sell Pack Height | 90 mm | |
| Product group | Semiconductor Protection Fuses | |
| Body/Insulating Material | Ceramic | |
| Product Weight | 0.8123 kg | |
| Power Dissipation at Rated Current Value | 130 W | |
| HS Code | 85361090 |
Frequently Asked Questions
What is the Mersen L300252 used for?
The L300252 is a high-speed semiconductor protection fuse designed to protect IGBTs, thyristors, diodes and other sensitive power electronic devices from short-circuit faults.
What is the current rating of the Mersen L300252?
The Mersen L300252 has a rated current of 800 A.
What voltage is the fuse rated for?
The fuse is rated for 690 V AC (IEC) and 700 V AC (UL).
What does the integrated striker do?
The built-in striker provides mechanical indication when the fuse operates and can be used with a compatible microswitch for remote monitoring.
Where is the Mersen L300252 typically installed?
It is commonly installed in industrial motor drives, converters, UPS systems, renewable energy equipment and other semiconductor-based power electronic assemblies.
Trusted Protection for Critical Power Electronics
Mersen Protistor® semiconductor fuses are trusted worldwide by machine builders, electrical engineers and power electronics manufacturers to deliver rapid fault protection, dependable performance and long-term equipment reliability.
