Square D FC34045 – 45A 3-Pole 480V I-Line Molded Case Circuit Breaker | 65kAIC Plug-In

Square D FC34045 – 45 Amp Molded Case Circuit Breaker | I-Line Plug-In | 3-Pole | 480V | 65kAIC

The Square D FC34045 is a heavy-duty, industrial-grade molded case circuit breaker designed for demanding commercial and industrial power distribution applications. With a 45-amp current rating, 3-pole configuration, 480V AC voltage rating, and an exceptional 65kA interrupting capacity at 480V, this FC-frame breaker is engineered to deliver superior short-circuit protection and reliable thermal-magnetic trip performance in I-Line panelboards and switchboards.

As part of Schneider Electric's Square D I-Line family, the FC34045 features a plug-in mounting style compatible with I-Line panelboards and switchboards — making installation faster and more convenient than bolt-on alternatives. Its Long-Time and Instantaneous (LI) trip functions provide two-stage protection: gradual response to sustained overloads and near-instant reaction to high-level short-circuit faults.

Key Technical Specifications

• Model / Part Number: FC34045
• Manufacturer: Square D / Schneider Electric
• Amperage: 45A
• Voltage Rating: 480V AC
• Poles: 3-Pole / 3-Phase
• Frame Type: FC-Frame (FA-Frame series, 15–100A range)
• Mounting Style: I-Line Style Plug-In
• Interrupting Capacity: 65kA @ 480V (High Interrupting Capacity)
• Trip Type: Thermal Magnetic – Long-Time and Instantaneous (LI)
• Operating Temperature: Calibrated at 40°C
• Phase: 3-Phase
• Series: I-Line
• Standards: UL Listed

What Is the Square D FC34045?

The FC34045 is a thermal-magnetic molded case circuit breaker (MCCB) manufactured by Square D (Schneider Electric). It uses a combination of a bimetallic strip (thermal element) for overload protection and an electromagnetic coil (magnetic element) for short-circuit protection — providing reliable, automatic fault detection without requiring an external power source or electronic components.

This breaker belongs to the FC-Frame class within Square D's FA-Frame series, engineered for high interrupting duty in industrial switchgear and panelboards. The I-Line plug-in design allows the breaker to slide into compatible bus bars, significantly reducing installation time on new builds and breaker replacements.

Applications & Compatibility

The Square D FC34045 is widely used across a range of commercial and industrial environments, including:

• Industrial facilities and manufacturing plants
• Commercial buildings and office complexes
• Motor branch circuit protection (3-phase motor loads)
• HVAC systems and mechanical equipment rooms
• Lighting distribution panels
• Feeder protection in I-Line panelboards and switchboards
• Data centers and utility rooms requiring high AIC ratings

The breaker is compatible with Square D I-Line panelboards and switchboards that accept FC-frame plug-in breakers. Always verify compatibility with your existing panel model before installation.

Why Choose the Square D FC34045?

• High Interrupting Capacity: 65kAIC @ 480V — exceeds standard breaker ratings, ideal for high-fault-current environments
• Plug-In Convenience: I-Line style plug-in mounting simplifies installation and replacement
• Dual Trip Protection: Long-Time and Instantaneous trip functions guard against both sustained overloads and sudden short circuits
• Industry-Trusted Brand: Square D by Schneider Electric is a globally recognized leader in power management and circuit protection
• UL Listed: Complies with UL standards for safety and performance
• 3-Phase Capability: Designed for balanced protection across all three phases in commercial and industrial power systems

Frequently Asked Questions

What does FC34045 stand for?
The FC34045 part number encodes key specifications: FC = Frame type (FC-frame, high interrupting capacity variant of the FA series), 3 = 3-pole, 4 = 480V, 045 = 45-amp rating.

What is the interrupting rating of the FC34045?
The FC34045 has a 65kA interrupting capacity at 480V AC, classifying it as a high interrupting capacity breaker — suitable for environments with high available fault current.

What panels is the FC34045 compatible with?
The FC34045 uses an I-Line style plug-in connection and is compatible with Square D I-Line panelboards and switchboards designed for FC-frame breakers. Refer to your panelboard's manufacturer specifications to confirm compatibility.

Is the FC34045 the same as the FA34045?
They are related but differ in interrupting capacity. The FA34045 typically has an 18kA AIC rating at 480V, while the FC34045 offers a much higher 65kA AIC — making the FC series the preferred choice in high fault-current environments.

What trip mechanism does the FC34045 use?
It uses a thermal-magnetic trip unit with Long-Time (LT) and Instantaneous (I) trip functions — providing two-layer protection against overloads and short circuits.

What is the operating temperature of the FC34045?
The FC34045 is calibrated for operation at 40°C ambient temperature. Derating may be required in higher temperature environments.