A50P400-4K Ferraz Shawmut - Fuse

A50P400-4K Description

The A50P400-4K from Mersen is a high speed fuse with a 500 V / 400 A rating. Its job is to clear faults fast enough to save expensive semiconductors in drives, UPS units and DC supplies.

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Summary of Features

Target Applications

Ferraz Shawmut A50P400-4K is used for protection of DC drives, uninterruptible power supplies (UPS) and other power electronic equipment of 500 V or less, including power semiconductor (diode, thyristor, IGBT) protection.

Key Specifications

Mersen (Ferraz Shawmut) A50P400-4K is an Amp-Trap Form 101 A50P high speed fuse, 400 A, 500 VAC / 450 VDC, blade, bolt-in (4K, round mounting hole) mounting. Source: Mersen A50P Amp-Trap Form 101 datasheet (HS 14-15, 2025).

Parameter	Value
Series	A50P Amp-Trap Form 101 high speed fuse
Rated current	400 A
Rated voltage	500 VAC / 450 VDC
Interrupting rating	100 kA AC / 79 kA DC (L/R 10 ms)
Mounting type	4K: blade, bolt-in (4K, round mounting hole)
Characteristics	Very fast acting, current limiting, low I²t, controlled arc voltage
Approvals	UL Recognized Component (JFHR2, file 60314): AC and DC
Overall length (A)	6.25 in (158.8 mm)
Body diameter / width (B)	1.50 in (38.1 mm)
Mounting hole centres (D)	120.7 mm
Matching fuse block	P266C

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