Built for robust power distribution, the Square D LJA36400U33X is a 3-pole, 400A electronic trip molded case circuit breaker. It is part of the PowerPacT L-Frame series, designed for heavy-duty commercial and industrial facilities. This unit installs into Square D I-Line panelboards and switchboards using a secure plug-on connection. It is equipped with a Micrologic 3.3S trip unit, offering adjustable long-time, short-time, and instantaneous (LSI) functions for precise system coordination.
What panelboards are compatible with the LJA36400U33X breaker?
This breaker installs directly into Square D I-Line panelboards and switchboards. It uses a plug-in jaw connection on the line side to attach to the bus assembly, and mechanical lugs on the load side.
What does the U33X suffix mean on this Square D breaker?
The U33X designates a Micrologic 3.3 S electronic trip unit. This specific trip unit provides adjustable Long-time, Short-time, and Instantaneous (LSI) protection functions.
How are conductors terminated on the LJA36400U33X?
The load side features mechanical lugs that accept two 2/0 AWG to 500 kcmil aluminum or copper conductors per phase. The line side relies entirely on the I-Line bus plug-in connection.
Can the LSI trip settings be adjusted on this breaker?
Yes, the integrated Micrologic 3.3 S trip unit features dial settings on the face of the breaker. These dials allow electricians to configure the pickup and delay for long-time and short-time functions, as well as the pickup for instantaneous faults.
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