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The A4BY1000 is a Gould 1000A, 600V Class J time delay fuse designed for effective protection of electrical circuits. Featuring a robust construction, this fuse ensures long-lasting performance and reliability in high-demand applications. Ideal for industrial and commercial use, it helps prevent equipment damage by accommodating temporary overloads.
The A4BY1000 is a Class J fuse, which requires a Class J–rated fuse holder or fusible disconnect rated for at least 1000A and 600V. Class J holders have a rejection feature that physically prevents installation of non-Class J fuses, so standard Class H or K holders will not accept this fuse.
The Gould A4BY series fuses are considered obsolete/discontinued under the current Ferraz Shawmut (now Mersen) product line. Northern Breaker Group specialises in hard-to-find and obsolete electrical components — contact us for current stock availability or to discuss a compatible modern replacement.
Yes. The A4BY1000's time delay characteristic makes it well suited for motor branch circuit protection, as it can ride through the normal inrush current during motor startup without nuisance blowing, while still providing fast response to short-circuit faults. Always verify the fuse ampere rating against the motor FLA and applicable CEC requirements for your installation.
