Built for industrial applications, the Square D Q4F3300 is a 3-pole, 300A molded case circuit breaker. It utilizes thermal-magnetic trip technology to deliver reliable long-time and instantaneous protection. This bolt-on MCCB integrates into Square D distribution panelboards, switchboards, and enclosures. It is frequently replaced by the modern PowerPacT LGL36400U31X when upgrading infrastructure. Featuring a 25kAIC rating at 240VAC, this breaker includes a Visi-Trip indicator.
What enclosures and panels are compatible with the Q4F3300?
This Q4 frame circuit breaker is designed for installation in Square D distribution panelboards, switchboards, and compatible industrial enclosures.
What wire sizes and materials are supported by the load lugs?
The load-side lugs accept either a single wire from 1 AWG to 600 kcmil or dual wires from 1 AWG to 250 kcmil. Both aluminum and copper conductors are supported.
How does the trip unit on the Q4F3300 function?
It utilizes a fixed thermal-magnetic trip unit. The thermal component provides long-time protection against mild overloads, while the magnetic component provides instantaneous protection against severe short circuits.
How can I safely test the tripping mechanism on this breaker?
Square D Q4 frame breakers feature a push-to-trip button on the front of the unit. This allows you to manually test the mechanical tripping action without exposing yourself to live electrical parts.
How does this breaker connect to the panel bus?
The Q4F3300 utilizes an I-Line style plug-in connection on the line side for quick installation onto the panelboard bus, while the load side uses standard mechanical lugs for wire termination.
Is the Q4F3300 part of a current or legacy breaker family?
The Q4F3300 is part of the Square D legacy molded case circuit breaker family. It utilizes the Q4 frame design, which is commonly found in older distribution panelboards and switchboards.
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