Snap disc thermostats used in air conditioner condensers provide mechanical temperature switching to prevent overheating during high-load conditions. These thermostats mount directly to the refrigerant line and interrupt power when line temperatures reach a calibrated limit. The Senasys 430 Series is engineered to monitor condenser coil temperature and respond instantly at preset actuation points.
Engineered for Direct Mounting on AC Condenser Coils
Thermostats in the 430 Series are designed for pipe mounting onto refrigerant tubing. The 430-301AA25-665 model, for example, opens the electrical circuit at 220°F, shutting off compressor power to avoid thermal overload. Once the refrigerant line cools below the reset threshold, the contacts automatically close, restoring operation.
This mechanical switching eliminates reliance on external temperature sensors or software-controlled logic.
430 Series Snap Disc Thermostat Specifications
Each 430 Series thermostat supports integration into HVAC and OEM platforms with features including:
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Mounting: ½” pipe mount for thermal contact with refrigerant lines
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Set points: Factory-calibrated trip temperatures from 0°F to 350°F
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Switch type: SPST (Single-Pole, Single-Throw), open or close on rise
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Reset behavior: Automatic reset upon cooldown
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Certifications: UL and cUL listed to UL 873 and UL 353
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Housing: Compact, sealed design for condenser unit environments
These thermostats operate solely based on thermal input at the mounting location, ensuring response is localized and immediate.
Direct Thermal Sensing at the Refrigerant Line
The 430 Series’ pipe mount design allows for thermal contact directly at the point of temperature rise—the condenser coil. This results in faster, more accurate response compared to ambient or surface-mounted alternatives. Installation requires no adhesive, standoff hardware, or calibration on site, reducing assembly steps and potential failure points.
Thermal response time is minimized by eliminating sensor lag and mounting variables.
Overheat Control Function in Air Conditioning Systems
During normal operation, high-pressure refrigerant passes through the condenser coil to release heat. Under conditions such as fan failure, blocked airflow, or overcharge, the refrigerant line can exceed safe temperatures. A 430 Series snap disc thermostat interrupts power at the set point to stop the compressor before overheating causes mechanical or electrical damage.
When the temperature stabilizes, the thermostat resets automatically, allowing the system to resume without manual intervention. Check out the below video for an overview of this application.
Application Flexibility and Customization Options
Senasys manufactures the 430 Series in the United States under tight quality control and offers custom trip temperatures to match specific cooling system requirements. While 430-301AA25-665 is a common configuration for 220°F shutoff, the full product line includes a wide range of set points and pipe mount sizes to accommodate diverse air conditioner condenser designs.
All models are UL and cUL recognized for integration into regulated HVAC equipment.
Applications for the Air Conditioner Condenser Snap Disc Thermostats
The 430 Series supports air conditioner condenser protection in applications such as:
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Fixed-trip shutoff for residential and commercial AC units
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Compressor cycling control based on refrigerant line temperature
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Overheat protection in rooftop condensers and split systems
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Fan operation control based on condenser coil temperature
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Equipment designs requiring mechanical temperature switching
By using a snap disc thermostat, OEMs and system integrators gain a precise thermal control method that requires no firmware, external sensors, or software programming.
For OEM pricing or to discuss application details with our engineering team, please contact us.
