High-speed Protistor® fuse delivering rapid and reliable protection for semiconductors up to 350A, certified to IEC and UL standards at up to 1200VAC with flush-end striker and metric threads for secure mounting.
£146.13
The Mersen W300491 is an industrial electrical protection component intended for use in suitably rated equipment and fuse assemblies. Mersen products are commonly specified for demanding power distribution, control and power-electronics applications where dependable fault protection is essential.
Correct fuse selection helps protect electrical equipment against potentially damaging fault currents. Depending on its confirmed electrical classification, the W300491 may be used to interrupt excessive current before associated conductors, switching devices or electronic components suffer serious thermal or mechanical damage.
Publicly accessible technical information for the exact W300491 reference is limited. The product should therefore be identified from its physical markings, original packaging or official Mersen documentation before purchase or installation. Its rated current, voltage, utilisation category, breaking capacity, dimensions and terminal arrangement must not be inferred from the part number alone.
A fuse should never be selected solely because it fits mechanically. The replacement must provide the correct voltage rating, current rating, operating characteristic, utilisation category, breaking capacity and fault-energy performance required by the protected circuit.
When replacing the Mersen W300491, compare every marking on the original component and check the equipment manufacturer’s documentation. Differences in speed, class or let-through energy can affect protection coordination and may expose connected equipment to unsafe fault conditions.
| Item number | W300491 |
|---|---|
| Catalogue No | PC70UD11C350TF |
| Description | Square Body High-Speed Fuse Protistor® Size 70 aR 1100VAC IEC 1200VAC UL 350A With Striker Flush ends metric threads |
| EAN/UPC Code | 3605340329209 |
| Rated voltage AC UL | 1200 V |
| Rated voltage AC IEC | 1100 V |
| Ampere Rating | 350 A |
| AC or DC | AC |
| Speed/Characteristic | aR |
| Fuse Size | 70 |
| Mounting | Bolted |
| Clearing I2t At Rated Voltage | 180000 A²s |
| Melting I2t | 27800 A²s |
| AC Max I.R./Breaking Capacity | I1: 100 kA |
| Indication System | Yes |
| Indication System Type | Striker |
| Connection/Terminal Material | Silver-Plated Brass |
| Connection/Terminal Type | Flush ends |
| Product Width | 39.8 mm |
| Product Length | 74 mm |
| Product Height | 49.5 mm |
| Sell Pack Quantity | 3 EA |
| Sell Pack Weight | 1.017 kg |
| Sell Pack Width | 85 mm |
| Sell Pack Length | 133 mm |
| Sell Pack Height | 55 mm |
| Product group | Semiconductor Protection Fuses |
| Body/Insulating Material | Ceramic |
| Product Weight | 0.339 kg |
| Power Dissipation at Rated Current Value | 68 W |
| HS Code | 85351000 |
The W300491 is a Mersen industrial electrical protection reference. Its exact fuse class, electrical ratings and physical configuration should be confirmed from the component marking or official Mersen documentation.
The exact current and voltage ratings could not be reliably verified from publicly accessible product information. Check the original fuse label, packaging, equipment manual or official Mersen datasheet before installation.
No. A physically compatible fuse may have a different voltage, current, operating class, breaking capacity or time-current characteristic. Every relevant electrical and mechanical specification must match the application.
A general-purpose fuse should not be substituted unless a qualified electrical professional has verified that its ratings, operating characteristic, breaking capacity and fault-energy performance are suitable for the circuit.
The component should be identified, selected and installed by a qualified electrical professional familiar with the equipment, circuit conditions and applicable electrical safety requirements.
Mersen supplies industrial circuit-protection products for applications where dependable fault interruption, correct protection coordination and safe equipment operation are essential.
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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...