Aaon P81570 Limit Switch

When you are dealing with high-capacity AAON units, the Aaon P81570 Limit Switch is a critical component for maintaining secondary safety and equipment integrity. This OEM replacement hi-limit switch is engineered with a 7-inch insert probe to provide accurate thermal sensing deep within the cabinet or ductwork, ensuring the system Reacts to over-temperature conditions before damage occurs to the heat exchanger or downstream components. Operating on an auto-reset mechanism, this 140-170F limit switch opens the control circuit when temperatures exceed the 170°F threshold and closes once they drop back to the 140°F range.

For field technicians, the P81570 offers an exact fit for commercial HVAC systems, eliminating the need for mounting modifications or bracket adjustments. The robust bimetal disc sensing element is housed in a durable assembly designed for high-cycle reliability in demanding rooftop environments. By utilizing this genuine AAON part, you ensure that the safety string remains compliant with original equipment manufacturer specifications, maintaining the precise operational parameters required for efficient heating cycles and long-term HVAC system protection.

• Precision Thermal Sensing: Features a fixed 140°F to 170°F operating range for consistent high-limit protection.
• Optimal Probe Depth: The 7-inch insert allows for deep-seated temperature monitoring in larger air handlers and furnaces.
• Automatic Reset: Reduces downtime by automatically re-engaging the system once safe temperatures are restored.
• Direct OEM Compatibility: Specifically designed for AAON equipment, ensuring proper electrical and physical integration.
• Enhanced Safety: Acts as a reliable failsafe to prevent heat exchanger overheating and potential fire hazards.

What happens if my limit switch fails to reset?
If the Aaon P81570 fails to close at 140°F, it usually indicates a mechanical failure within the bimetal disc or significant oxidation on the contacts, requiring an immediate OEM replacement to restore heating functionality.

Can I use a shorter insert for this AAON model?
No, the 7-inch insert is specified to reach the core airflow path. Using a shorter probe may result in delayed tripping or inaccurate sensing, which compromises the safety of the furnace or air handler.

Is this switch compatible with 24V or 120V circuits?
This hi-limit switch is typically used in low-voltage safety strings, but you should always verify the amperage rating against your specific AAON wiring schematic to ensure circuit compatibility.

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.