Square D HJA36050SA 50A 3-Pole 600 V Circuit Breaker Potential Transformer

The Square D HJA36050SA is a rugged, three‑phase circuit breaker with an integrated potential transformer, purpose-built for reliable protection and precise measurement in demanding electrical environments. With a 50 A rating, 3 poles, and a 600 V maximum rating, this unit is designed to safeguard and monitor modern power distribution in commercial, industrial, and data-center settings.

• Current rating: 50 A continuous protection for typical 3‑phase loads
• Poles: 3 (three‑phase) configuration for balanced protection across all lines
• Voltage rating: Up to 600 V system voltage, suitable for a wide range of distributions
• Integrated potential transformer: Provides accurate sensing signals for metering, protective relays, and monitoring equipment, reducing wiring complexity and speeding diagnostics
• Compact, industry‑standard form factor: Designed to fit within standard Switchgear and panelboard assemblies, simplifying upgrades and retrofits
• Part number: HJA36050SA ensures seamless compatibility with existing Square D components and spare parts

Use cases and scenarios

Whether you’re equipping a factory motor control center, a commercial data center, or a high‑demand processing plant, this device delivers integrated protection and measurement in one compact unit. The three‑pole design supports true three‑phase protection, helping prevent voltage imbalance and overcurrent conditions across all phases. The built‑in potential transformer feeds accurate signals to protective relays and energy meters, enabling real‑time visibility into current flow and voltage levels without the need for extra transformers or complex wiring.

Why this matters in real life

• Streamlined installations: With an integrated PT, you reduce wiring runs and potential connection errors, accelerating panel builds and upgrades.
• Improved monitoring: Direct, reliable measurement signals support faster fault detection and more precise energy management.
• Space‑savvy protection: A compact, three‑pole package fits into tight switchgear footprints without sacrificing performance.
• Trusted heritage: Square D’s robust engineering and compatibility with existing Square D components simplify maintenance and future expansions.

Practical guidance for deployment and care

Before installation, confirm that the application is within the 600 V rating and that the load characteristics align with the 50 A protection level. Pair this breaker with compatible Square D accessories to maximize performance and ensure reliable relay and metering signals from the integrated potential transformer. Regular inspections should verify clean terminations, intact labeling, and secure mounting to maintain accurate sensing and protection over time.

Ideal for professionals who value precise measurement, straightforward wiring, and dependable, phase‑balanced protection in one integrated solution. The Square D HJA36050SA brings together current protection and voltage sensing in a single, versatile unit—a smart upgrade for any three‑phase power distribution.