Mersen A50QS350-4 Semiconductor Fuse 350A 500V AC Bolt-On

Mersen A50QS350-4 Semiconductor Fuse

The Mersen A50QS350-4 is a fast-acting semiconductor fuse rated for 350A at 500V AC and 500V DC. It is designed for electrical engineers and maintenance technicians protecting power semiconductors in industrial equipment. The bolt-on body style allows secure mounting directly onto busbars or terminal blocks. This non-indicating fuse suits applications where visual blown-status indication is not required.

Interrupt rating and voltage headroom

The fuse delivers an interrupt rating of 200kA at 500V AC and 87kA at 500V DC, providing substantial fault-current clearance for heavy industrial supplies. It comfortably handles continuous loads up to its 350A rating within the A50P series envelope. The single-element construction ensures predictable fast-acting response under short-circuit conditions. Systems requiring higher interrupt capacity or different voltage ratings will need a different fuse class.

Bolt-on mounting constraint

The 4-3/8 inch length by 1-1/2 inch diameter fiberglass body uses a bolt-on termination that dictates panel layout and busbar drilling patterns. Installers must verify that the physical footprint and mounting hardware match the existing hardware before ordering. The non-rejection design means it fits standard A50QS, FWH and L50S clips without a keying feature. Buyers needing rejection-style or indicating fuses cannot use this part.