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Transparent cylindrical fuse with bolt-on end caps, 250A 500V AC/DC fast-acting semiconductor fuse

Mersen

Mersen A50QS250-4 Semiconductor Fuse 250A 500V AC Bolt-On

SKU CH-7298-RNDSR

Fast-acting semiconductor fuse rated 250 A at 500 V AC and 500 V DC with 200 kA interrupt capacity

  • TypeFuses & Accessories
  • ColorTransparent
  • Fast-acting protection for semiconductor circuits
  • 250 A rating handles high-current industrial loads
  • 500 V AC and DC voltage rating suits diverse power systems
  • 200 kA interrupt rating at 500 V AC clears severe faults safely
  • UL Recognized and CSA Certified for code-compliant installations

Purpose and fit

This Mersen A50QS250-4 semiconductor fuse protects power semiconductors in industrial and commercial equipment rated up to 500 V AC or DC at 250 A. Its fast-acting, single-element design interrupts fault current quickly to limit let-through energy. The bolt-on body style suits panel or busbar mounting where a secure, non-rejection connection is required.

Build integration

The fiberglass body measures 4-3/8 in long by 1-1/2 in diameter and uses a bolt-on termination, so it fits into existing fuse blocks or custom buswork without clips. A 200 kA interrupt rating at 500 V AC and 87 kA at 500 V DC means the fuse can clear high prospective short-circuit currents without upstream coordination changes. CE, UL Recognized (Guide JFHR2, File 60314) and CSA Certified (LR12636) markings simplify compliance documentation.

Sustained-load behaviour

Under continuous rated current the single element runs at a stable temperature because the fiberglass body dissipates heat evenly. During prolonged overloads the fast-acting characteristic melts the element before semiconductor junctions reach destructive temperatures. The non-indicating construction means no visual flag or microswitch is fitted, so status monitoring must be provided externally if required.

Highlights

  • Fast-acting protection for semiconductor circuits
  • 250 A rating handles high-current industrial loads
  • 500 V AC and DC voltage rating suits diverse power systems
  • 200 kA interrupt rating at 500 V AC clears severe faults safely
  • UL Recognized and CSA Certified for code-compliant installations

Specifications

BrandMERSEN
TypeFuses & Accessories
ColorTransparent

Questions about this item

How many amps can the A50QS250-4 carry continuously before it opens?

The fuse is rated for 250 A continuous current; it will open when the load exceeds that value.

How hot or noisy does the fuse get during all-day operation?

A correctly rated fuse runs silently and without noticeable heat rise; only an overload produces measurable temperature increase.

What mounting hardware must I already have to install this bolt-on fuse?

You need a fuse block or bus bars drilled for the bolt-on body style so the fuse can be secured with bolts.

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