Square D LA and LH Breakers 125A to 400A

Reliable electrical circuit protection meets performance with Square D LA and LH breakers 125 – 400A.

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Table Of Contents
  1. Key Features of LA and LH Series Circuit Breakers
  2. Choosing the Right Square D LA or LH Breaker
  3. Install Square D LA and LH Breakers
  4. Popular LA and LH Breaker Models
  5. FAQ: Test Your Knowledge of LA and LH Breakers

If you’ve been looking for industrial circuit protection that combines dependability and performance, Square D’s LA and LH Series Circuit Breakers should be on your list. These thermal-magnetic circuit breakers provide important overload and short-circuit protection for applications that range from 125 to 400 amps. When you’re replacing an existing panel or installing new equipment, these breakers provide the flexibility and safety you need.

Key Features of LA and LH Series Circuit Breakers

Understanding these key features will help you choose the right breaker for your system. More importantly, you’ll see how each feature directly benefits your operation.

Thermal-Magnetic Protection ensures well-rounded system safety by using a thermal element for overload protection and a magnetic trip for short circuits.
✔ Why this matters: You’ll minimize equipment failures and avoid unexpected downtime due to overloads or short circuits.

High Interrupting Capacity makes LH series breakers ideal for high-fault environments, offering up to 65kA interrupting capacity at 240V AC.
✔ Why this matters: Your electrical system will be protected even in the most demanding industrial settings, preventing costly damage from high fault currents.

Versatile Mounting Options provide flexibility with unit-mount, I-Line plug-on, and rear-connected configurations to match your panel requirements.
✔ Why this matters: You get installation flexibility, allowing you to integrate these breakers into various power distribution systems without major modifications.

Push-to-Trip Button allows for quick manual testing of the breaker’s operation without exposing yourself to live electrical components.
✔ Why this matters: You’ll be able to safely verify breaker functionality during maintenance, avoiding surprises when an actual fault occurs.

Clear Trip Indication moves the breaker handle to a center position when tripped, offering an immediate visual alert.
✔ Why this matters: You can quickly diagnose and resolve power disruptions, improving system uptime and safety.

Choosing the Right Square D LA or LH Breaker

Not sure which Square D molded case breaker is right for your setup? Here’s how to decide:

  • Check the Current Rating: LA and LH breakers range from 125A to 400A— match your breaker to your system’s expected electrical load.
  • Assess Interrupting Capacity: LH series breakers have higher interrupting ratings, so they’re better for locations with high fault currents.
  • Determine Mounting Type: Choose unit-mount breakers for standard applications, I-Line for panelboards, or rear-connected breakers for specialized setups.
  • Verify Voltage Requirements: Make sure the breaker’s voltage rating matches your system’s needs (600V AC, 250V DC, etc.).

By choosing the right breaker, you’ll improve both electrical system safety and long-term reliability.

square d thermal magnetic molded case
Thermal magnetic protection from 125 to 400A Square D molded case circuit breakers (Source: Schneider Electric).

Install Square D LA and LH Breakers

Proper installation is important for safety and performance. If you’re certified to work on these breakers, follow these steps:

  1. Turn Off Power: Always disconnect power before working on any electrical equipment.
  2. Verify Specifications: Double-check that the breaker meets your system’s voltage and current requirements.
  3. Mount the Breaker: Secure the breaker in place based on your panel type (unit-mount, I-Line, etc.).
  4. Connect the Conductors: Use the correct wire size and make sure connections are tight to prevent overheating.
  5. Test the Breaker: Use the push-to-trip button and verify continuity to make sure proper functionality before energizing.

By following these steps, you’ll install your Square D power distribution breaker safely.

Here are some top models and their common applications:

  • LAL36300 (300A, 600V AC, 22kA) – Used in commercial and industrial panelboards.
  • LHL36400 (400A, 600V AC, 50kA) – Ideal for high-fault industrial environments.
  • LHL36300 (300A, 600V AC, 50kA) – Often found in heavy-duty applications requiring both AC and DC support.

No matter your application, there’s a Square D LA or LH breaker that fits your needs.

square d LA and LH breaker selection
Square D Molded Case Circuit breakers give reliable protection for electrical equipment in a high-tech manufacturing facility, protecting against overloads and short circuits.

FAQ: Test Your Knowledge of LA and LH Breakers

By understanding these key points, you’ll make informed decisions about Square D electrical components for your projects.

With the right Square D LA or LH breaker, you’ll make sure safe, reliable power distribution for your industrial or commercial system. Looking for specific models? Let us help you find the best option for your needs. Shop for molded case breakers.