Square D FA34045 Molded Case Circuit Breaker – 45A 3-Pole 480V I-Line Plug-In | 18kAIC

Square D FA34045 – 45 Amp Molded Case Circuit Breaker | I-Line Plug-In | 3-Pole | 480V | 18kAIC

The Square D FA34045 is a thermal-magnetic molded case circuit breaker (MCCB) engineered for reliable overcurrent and short-circuit protection in industrial and commercial power distribution systems. With a 45-amp rating, 3-pole configuration, and 480VAC voltage rating, this breaker is a proven performer in demanding electrical environments.

What Is the Square D FA34045?

The FA34045 belongs to Square D's FA-frame series — a compact, high-performance line of molded case circuit breakers designed for use in I-Line panelboards and switchboards. It features plug-in I-Line style connections, allowing for fast, tool-free installation and replacement in compatible Square D I-Line panels.

• Brand: Square D (Schneider Electric)
• Part Number: FA34045
• Ampere Rating: 45A
• Poles: 3-Pole
• Voltage Rating: 480VAC
• Interrupting Rating: 18,000 AIC (18kAIC) at 480V
• Trip Type: Thermal-Magnetic (LI – Long-Time & Instantaneous)
• Connection Type: I-Line Style Plug-In
• Frame: FA Frame
• Standards: UL Listed, NEMA rated

Key Features

Thermal-Magnetic Trip Mechanism

The FA34045 uses a dual-function LI trip unit — combining long-time delay for overload protection and instantaneous trip for short-circuit response. This ensures both equipment and wiring are protected against sustained overloads and sudden fault currents.

I-Line Plug-In Connection

Designed exclusively for Square D I-Line panelboards, the plug-in design eliminates the need for separate lugs or bolt connections. Breakers can be installed and replaced quickly, reducing downtime during maintenance or upgrades.

18kAIC Interrupting Capacity

With an 18,000 ampere interrupting capacity at 480V, the FA34045 safely interrupts fault currents in most light commercial and industrial applications without damage to the breaker or panel.

3-Pole Design for 3-Phase Systems

The 3-pole configuration provides simultaneous protection on all three phases of a 480VAC three-phase system — the standard for motors, HVAC equipment, compressors, and industrial machinery.

Common Applications

• Motor branch circuit protection (up to 45A)
• HVAC and refrigeration equipment
• Industrial machinery and manufacturing lines
• Commercial building electrical distribution panels
• Replacement in existing Square D I-Line switchboards

Is the FA34045 Compatible with My Panel?

The Square D FA34045 is compatible with Square D I-Line style panelboards and load centers that accept FA-frame plug-in breakers. Always verify your panel's bus rating, frame compatibility, and available space before installation. Consult your panel's nameplate or Square D documentation for approved breaker types.

Why Buy from Alpha Brokers & Controls?

We specialize in new, surplus, and hard-to-find circuit breakers from top manufacturers including Square D, Eaton, Siemens, and GE. Our inventory is inspected and verified before shipping. Whether you need a direct replacement or sourcing support for obsolete equipment, we're here to help.

Frequently Asked Questions

What does FA34045 mean?

In Square D's naming convention: FA = FA frame series, 3 = 3-pole, 4 = 480V voltage class, 045 = 45-amp rating. The "I-Line" suffix indicates the plug-in bus connection style.

What is the interrupting rating of the FA34045?

The FA34045 has an interrupting rating of 18,000 AIC (18kAIC) at 480VAC.

Can the FA34045 be used in a Square D QO or Homeline panel?

No. The FA34045 is designed specifically for Square D I-Line style panelboards. It is not compatible with QO or Homeline residential panels, which use different frame and bus designs.

Is this breaker UL Listed?

Yes. The Square D FA34045 is UL Listed and manufactured to NEMA and ANSI standards for molded case circuit breakers.

What trip type does the FA34045 use?

The FA34045 features a thermal-magnetic LI trip unit, providing long-time (overload) and instantaneous (short-circuit) protection.