Built for demanding commercial applications, the Square D HJA36100U44X is a 100A, 3-pole electronic trip circuit breaker. As part of the PowerPact H-Frame series, it delivers true RMS sensing and superior coordination. Designed for seamless integration, it installs into Square D I-Line panelboards and switchboards. The I-Line mounting style allows for quick phase connections. It features a Micrologic 6.2A trip unit, providing configurable LSIG protection and an integrated ammeter.
What panelboards accept the HJA36100U44X circuit breaker?
This breaker features an I-Line plug-in mounting style and is designed exclusively for Square D I-Line panelboards and switchboards. It cannot be installed in standard NQ, NF, or QO enclosures.
What does the U44X suffix mean on this PowerPacT breaker?
The U44X suffix indicates the breaker is equipped with a Micrologic 6.2A electronic trip unit. This provides adjustable LSIG (Long-time, Short-time, Instantaneous, and Ground-fault) protection and includes an integrated ammeter for current monitoring.
Does the HJA36100U44X provide ground-fault protection?
Yes, the included Micrologic 6.2A trip unit features LSIG functions, which includes integrated equipment ground-fault protection alongside standard overload and short-circuit protection.
How does the I-Line mounting style work on the HJA36100U44X?
The I-Line mounting system uses a plug-on design that connects directly to the panelboard bus stack. This allows for faster installation and phase balancing without the need for individual cable connections to the bus.
Can I replace a standard thermal-magnetic H-Frame breaker with the HJA36100U44X?
Yes, as long as the panel is an I-Line configuration and the system requires 100A or less. The HJA36100U44X shares the same physical H-Frame footprint but upgrades the protection to a solid-state Micrologic electronic trip unit.
What conductor materials are compatible with the lugs on this breaker?
The factory-installed lugs on the HJA36100U44X are dual-rated for both copper and aluminum wire, accepting sizes from 14 AWG to 3/0 AWG.
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Review summary
Customers rate this product 4.7 out of 5 based on 15 reviews.