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Square D LDA36400CU33X Molded Case Circuit Breaker

  • 400A
  • 3 Pole
  • I-Line
Square D LDA36400CU33X
Molded Case Circuit Breaker
Brand Square D
SKU LDA36400CU33X
Select Item Condition
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  • 400A
  • 3 Pole
  • I-Line

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Square D LDA36400CU33X - 400A 3 Pole Molded Case Circuit Breaker

Square D LDA36400CU33X - 400A 3 Pole Molded Case Circuit Breaker

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$6,960.00 In Stock

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Description

Providing advanced system coordination, the Square D LDA36400CU33X is a 3-pole, 400A electronic trip circuit breaker. This 100% rated PowerPacT L-Frame MCCB is built to handle continuous industrial loads safely and efficiently. It mounts into Square D I-Line panelboards and switchboards, utilizing a robust plug-on connection for rapid deployment. The integrated MicroLogic 3.3S trip unit delivers precise, adjustable long-time, short-time, and instantaneous (LSI) protection settings.

Specifications

Key specifications
Brand Square D
Part Number LDA36400CU33X
Series LDA
Amperage 400A
Poles 3
Mounting Style I-Line
Voltage 240VAC, 480VAC, 600VAC
Phase 3
AIC Rating 25kA @ 240VAC, 18kA @ 480VAC, 14kA @ 600VAC
Electrical ratings
Amperage Range 160-400A
Fit and installation
Frame Type LDA
Terminal Type Lugs
For Use With Square D I-Line Panelboards, Square D I-Line Switchboards
Wire Gauge 2 x 2/0 AWG - 500 kcmil (Al/Cu)
Max Wire 500 kcmil
Min Wire 2/0 AWG
Protection and operation
Trip Technology Electronic Trip
Trip Function Code LSI
Trip Function Long-Time, Short-Time, Instantaneous
Trip Adjustability Adjustable
Standards and features
Available Options Shunt Trip, Auxiliary Switch, Undervoltage Release, Alarm Switch, Padlock Attachment, Communication Module
Accessories Lugs
Standards CSA C22.2 No. 5, IEC 60947-2, NEMA AB 1, UL 489
Approval CE, CSA, IEC, NEMA, NOM, UL
Temp Rating -25C to 70C
Construction Features 100% Rated, HACR Rated, Visual Trip Indicator, True RMS Sensing, RoHS Compliant, Mercury Free

Product FAQs

6 answers
What does the "C" in the LDA36400CU33X catalog number indicate?

The "C" indicates that this circuit breaker is 100 percent rated. It can carry its full 400A continuous current rating without the standard 80 percent derating, provided it is installed in a properly sized enclosure with 90 degree Celsius rated wire.

How do I decode the LDA prefix in this catalog number?

In the Square D nomenclature, the "L" stands for the PowerPacT L-Frame, the "D" indicates the standard interrupting rating tier, and the "A" specifies the I-Line plug-on mounting style.

What type of trip unit is included with the LDA36400CU33X?

This breaker features a Micrologic 3.3S electronic trip unit, indicated by the "U33X" in the catalog number. It provides adjustable Long-Time, Short-Time, and Instantaneous (LSI) protection settings for precise system coordination.

How does the I-Line connection work on the LDA36400CU33X?

The I-Line mounting style uses a plug-on design that connects directly to the busbar stack in an I-Line panelboard. This allows for faster installation and eliminates the need for line side wire connections, while the load side utilizes standard mechanical lugs.

Why use an electronic trip unit like the Micrologic 3.3S instead of a thermal magnetic breaker?

Electronic trip units provide highly accurate, adjustable trip curves that do not drift with ambient temperature changes. The LSI functions allow panel builders to fine-tune short circuit and overload protection to prevent nuisance tripping and improve system safety.

What is the physical frame size of the LDA36400CU33X?

This is a PowerPacT L-Frame circuit breaker. All L-Frame breakers share the same physical dimensions and mounting footprint, making them interchangeable within the panel regardless of their specific amp rating between 250A and 600A.

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