The 50A LET fuse you mentioned refers to the Eaton Bussmann 50LET model. This fuse is a British Standard (BS88) high-speed semiconductor protection fuse, designed specifically for circuits that need extremely fast protection against overcurrent and short circuits-1-2.
For a clear overview, here are its core specifications:
| Feature | Specification | Details / Note |
|---|---|---|
| Model | Eaton / Bussmann 50LET-1 | |
| Current Rating | 50 Amps-1-2 | |
| Voltage Rating | 240V AC / 150V DC-1-2 | The official AC rating is 280V-1. |
| Speed & Category | Very Fast Acting (FF) / Class aR-1-2 | For semiconductor protection (e.g., diodes, thyristors). |
| Breaking Capacity | 200 kA (AC & DC)-1-3 | Interrupts very high fault currents safely. |
| Physical Size | Approx. 56mm long, 18mm diameter-1-2 | Compact, with 41mm (41.8mm) fixing centers for mounting-1-2. |
| Terminal Type | Offset Bolted Tags-1-2 | Designed for bolted connections to a fuse holder. |
| Standards | BS88, IEC 60269-4-1-2 | British and international standards. |
???? Key Application Details
Understanding these points will help you determine if this is the correct fuse for your needs:
Primary Use: This fuse is engineered for protecting sensitive semiconductor devices like those found in DC drives, power converters, rectifiers, and common DC bus systems-1. Its "aR" classification and very fast speed are crucial for preventing thermal damage to these components during faults-2.
What “aR” Means: The “aR” (accompanied semiconductor protection) category means it can safely interrupt partial fault currents but is not designed to provide protection against overloads-1. Overload protection must be provided by another device (like a slower fuse or a circuit breaker) in the circuit.
Mounting: It has offset bolted tags (blade ends) and is designed to be mounted using M6 studs-1. Ensure your fuse holder or base is compatible with the LET size and the 41mm fixing centers-2.
???? Purchasing Information
This fuse is available from major industrial electronics distributors. Prices and stock vary:
RS Components: Lists the fuse with stock available and provides bulk pricing (e.g., ~MYR 72.90 for 1 unit)-2.
Allfuses.com: Shows a price of $26.14 with 34 units in stock-3.
Official Source: For definitive technical specifications and support, you can refer to the official Eaton product page-1.
⚠️ Important Safety Notes
Not for General Purpose: Do not use this as a general-purpose or branch circuit fuse. Its aR classification makes it unsuitable for protecting cables or loads from general overloads.
Consult Standards & Manuals: Always verify compatibility with your specific equipment and local electrical codes. For critical applications, consulting the equipment manual or a qualified electrical engineer is strongly advised.
I hope this detailed information is helpful. If you can share what specific equipment or application you need this fuse for, I might be able to provide more tailored guidance. https://store.unigulfsupply.com/product/eaton-50a-british-standard-fuse-let-150-v-dc-240v-ac/