Square D HDL36125 - 125 A, 600 V, 3-Pole Circuit Breaker | AmpState

Meet the Square D HDL36125—a dependable, high-performance 125 A, 600 V, 3-pole molded case circuit breaker designed to protect your electrical system where it matters most. Built for reliable branch circuit overcurrent and short-circuit protection in panelboards and loadcenters, this unit maximizes space without compromising protection.

Key advantages that matter in real-world installations

• Compact molded case design maximizes panel space, making it easier to fit large circuits in tight electrical enclosures.
• Thermal-magnetic trip unit delivers stable, repeatable protection—the thermal element responds to overloads with predictable trips, while the magnetic element rapidly interrupts high fault currents for fast isolation.
• 125 A, 600 V, 3-pole configuration is ideal for protecting 3-phase circuits common in commercial and light industrial settings, while also accommodating certain single-phase installations in mixed-use panels.
• OEM-compatible design ensures a seamless fit with matching Square D loadcenters and panelboards, simplifying replacement and maintenance.
• Versatile across applications suitable for residential, commercial, and light industrial electrical distributions, making it a practical choice for diverse projects.

Ideal use cases

Use the HDL36125 to safeguard feeders and branch circuits that power lighting, outlets, HVAC components, motors, and equipment in panelboards and loadcenters. Its precise trip characteristics help minimize downtime by isolating only the affected circuit, while the rest of the system continues to operate normally.

How it protects your system

The thermal-magnetic mechanism provides a two-tier response: the thermal element handles gradual overloads for stable protection, and the magnetic element engages during high-current faults to quickly interrupt the circuit. This combination reduces wiring damage, protects connected devices, and enhances overall system reliability in both new installations and panelboard retrofit projects.

Technical specifications

• Manufacturer: Square D
• Part Number: HDL36125
• Type: Thermal-magnetic molded case circuit breaker
• Amperage Rating: 125 A
• Voltage Rating: 600 V
• Number of Poles: 3
• Application: Branch circuit overcurrent and short-circuit protection

Compatibility and installation

This unit is designed to be compatible with matching OEM Square D loadcenters and panelboards, ensuring a straightforward, reliable replacement or installation. For best results, pair the HDL36125 with a Square D panelboard configured to accept molded-case breakers, and follow standard electrical codes during wiring and commissioning.