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Square D LGP36400U31X Molded Case Circuit Breaker

  • 400A
  • 3 Pole
  • Unit Mount
Square D LGP36400U31X
Molded Case Circuit Breaker
Brand Square D
SKU LGP36400U31X
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  • 400A
  • 3 Pole
  • Unit Mount

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Square D LGP36400U31X - 400A 3 Pole Molded Case Circuit Breaker

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$4,205.00 In Stock

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Description

Engineered for reliable commercial and industrial power distribution, the Square D LGP36400U31X is a 400A, 3-pole PowerPacT L-Frame circuit breaker. It provides robust overcurrent protection for demanding electrical infrastructure. Designed as a unit-mount MCCB, it installs into Square D QED switchboards, control panels, and enclosures. The breaker utilizes a dual-break rotary contact structure and includes standard lug terminals for secure connections.

Specifications

Key specifications
Brand Square D
Series LGP
Amperage 400A
Poles 3
Mounting Style Unit Mount
Voltage 240VAC, 480VAC, 600VAC
Phase 3
AIC Rating 65kA @ 240VAC, 35kA @ 480VAC, 18kA @ 600VAC
Electrical ratings
Amperage Range 125-400A
Fit and installation
Frame Type L
Terminal Type Lugs
For Use With Square D QED Switchboards, Control Panels, Enclosures
Wire Gauge (2) 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 LI
Trip Function Long-Time, Instantaneous
Trip Adjustability Adjustable
Standards and features
Available Options Shunt Trip, Auxiliary Switch, Undervoltage Release, Alarm Switch, Padlock Attachment, Motor Operator, Rotary Handle, Lug Kits, Terminal Shields
Accessories MicroLogic 3.3 Trip Unit
Standards CSA C22.2 No. 5, IEC 60947-2, NEMA AB 1, UL 489
Approval CCC, CE, CSA, IEC, NEMA, NOM, UKCA, UL
Temp Rating -25C to 70C
Construction Features HACR Rated, True RMS Sensing, Visual Trip Indicator, Dual-Break Rotary Contact Structure, 80% Rated, Mercury Free, PVC Free, RoHS Compliant, Trip-Free Mechanism

Product FAQs

10 answers
What does the "U31X" suffix mean in the LGP36400U31X catalog number?

The U31X suffix indicates the breaker is equipped with a MicroLogic 3.3 electronic trip unit. This provides adjustable Long-Time (L) and Instantaneous (I) trip functions for precise overcurrent protection and system coordination.

Is the LGP36400U31X rated for 100 percent continuous current?

No, this breaker is standard-rated for 80 percent continuous current. For a 100 percent rated version, a different catalog number with a specific suffix is required.

What wire sizes are compatible with the load-side lugs on this 400A breaker?

The standard load-side lugs accept two 2/0 AWG to 500 kcmil aluminum or copper conductors per phase. Ensure proper torque specifications are followed during installation.

What is the difference between the LGP36400U31X and LGP36400U33X?

The LGP36400U31X features a MicroLogic 3.3 trip unit with Long-Time and Instantaneous (LI) protection. The LGP36400U33X includes a MicroLogic 3.3S trip unit, which adds Short-Time (LSI) protection for enhanced coordination.

What panels or enclosures is this L-frame breaker compatible with?

This unit-mount, bolt-on breaker is designed for use in Square D QED switchboards, industrial control panels, and standalone enclosures. It is not designed for I-Line panelboards, which require an I-Line specific plug-on mounting bracket.

Does this breaker include ground fault protection?

No, the MicroLogic 3.3 (U31X) trip unit only provides Long-Time and Instantaneous (LI) protection. If equipment ground fault protection (LSIG) is required, you will need a breaker equipped with a MicroLogic 6.3 trip unit.

What does the "G" stand for in the LGP36400U31X part number?

The "G" indicates the interrupting capacity tier for this PowerPacT L-frame breaker. It signifies a rating of 65kA at 240VAC, 35kA at 480VAC, and 18kA at 600VAC.

Are the trip settings on the LGP36400U31X adjustable?

Yes, the MicroLogic 3.3 electronic trip unit features adjustable dials for both the Long-Time pickup and delay, as well as the Instantaneous pickup, allowing you to coordinate the breaker with your specific system requirements.

What does the "P" signify in the LGP36400U31X catalog number?

In the Square D PowerPacT nomenclature, the "P" indicates the termination style. It specifies that the breaker has a terminal nut connection on the line side and mechanical lugs on the load side, which is common for unit-mount switchboard installations.

What safety precautions should be taken before adjusting the MicroLogic trip unit?

Always ensure the breaker is de-energized and properly locked out and tagged out (LOTO) before removing the trip unit cover or making adjustments. Only qualified personnel should perform commissioning and coordination.

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