Carrier HH19ZA140 Limit Switch

The Carrier HH19ZA140 Limit Switch is a high-precision safety component engineered for HVAC systems requiring an L140-40F thermal threshold. Designed with a normally closed circuit, this disc-style switch is rated to open on a temperature rise at 140°F and automatically reset when the temperature drops to 100°F. As an OEM replacement part, it ensures seamless integration and maintains the original equipment’s safety ratings and system efficiencies. The automatic reset mechanism eliminates the need for manual intervention after a thermal event, making it a reliable choice for commercial and residential furnace applications.

This HVAC limit switch features a rugged construction suitable for demanding environments. It serves as a direct drop-in replacement for several older part numbers, including 71081D3, HH19ZA440, and P331-2143. By monitoring internal temperatures, the Carrier HH19ZA140 protects the heat exchanger from overheating, ensuring consistent performance and preventing premature equipment failure. For contractors, the compact design and standardized mounting make it a versatile thermal limit control for Carrier, Bryant, and Payne equipment.

• Precise Thermal Control: Factory-calibrated to open at 140°F and close at 100°F for accurate system protection.
• Automatic Reset: Streamlines system operations by resetting without manual labor once temperatures stabilize.
• Broad Compatibility: Replaces multiple legacy part numbers including HH19ZA440 and P331-2143.
• Durable Construction: Built to withstand the harsh thermal cycling of industrial and residential heating units.
• OEM Standards: Ensures original performance specs and sound quality requirements are maintained.

• What does the 'L140-40F' designation mean? The 'L' stands for Limit, 140 is the opening temperature (140°F), and 40 represents the differential (140°F minus 40°F equals a 100°F reset point).
• Is this switch compatible with other brands? While designed for Carrier, Bryant, and Payne, it can replace other L140-40F limit switches if physical dimensions and electrical ratings match.
• Why did my original limit switch trip? Common causes include restricted airflow from a dirty filter, a failing blower motor, or an oversized furnace for the ductwork.

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Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.