KSD9700 250V 5A Metal Thermostatic Temperature Switch NC 80° C

KSD9700 Thermostatic Temperature Switch, specifically the 80°C Normally Closed (NC) 250V 5A model, provides a reliable and cost-effective thermal cutoff or protection solution for electronic and electrical systems. This critical component utilizes a bimetallic strip enclosed in a compact metal casing to sense ambient temperature. When the temperature reaches the rated 80°C, the bimetallic element quickly snaps open, instantly interrupting the circuit. Since this is a Normally Closed (NC) device, it conducts current below 80°C and breaks the circuit at or above 80°C, offering essential safety against overheating in appliances and industrial controls.

Key Features:

• Fixed Trip Temperature: This model is factory set to open the circuit at a nominal 80°C, providing precise and non-adjustable over-temperature protection.
• Normally Closed (NC) Configuration: The contacts remain closed and allow current to flow when the temperature is below the trip point, automatically opening upon overheating.
• High Current Rating: It directly handles up to 5A at 250V AC, allowing control of many appliances and high-power relay coils without an intermediate stage.
• Quick Snap Action: The bimetallic disk provides fast, reliable, and clean switching action upon reaching the set temperature, minimizing arcing.
• Metal Housing: The durable metal case facilitates efficient heat transfer from the monitored device, ensuring accurate and rapid temperature sensing.

Technical Specifications:

• Switch Type: Normally Closed (NC)
• Rated Voltage: 250 V AC (Max)
• Rated Current: 5 A (Max resistive load)
• Action Temperature (T_ON): 80°C ± 5°C
• Reset Temperature (T_OFF): ≈ 60°C (The switch typically re-closes after cooling by 15°C to 20°C)
• Contact Resistance: ≤ 50 mΩ
• Insulation Resistance: ≥ 100 MΩ (500 V DC)

Mechanical Specifications:

• Package Style: Metal Thermostat with mounting flange
• Switch Mechanism: Bimetallic Disc Thermostat (snap-action)
• Lead Material: High-temperature insulated wire leads
• Electrical Life: ≥ 50,000 Cycles
• Mounting: Fixed mounting flange (requires screws or adhesive) for secure thermal coupling.
• Operating Temperature Range: −10°C to +150°C (Max ambient, non-switching)

Dimensions:

• Body Diameter: ≈ 10 mm
• Body Thickness: ≈ 5 mm
• Mounting Flange Width: ≈ 15 mm
• Lead Length: ≈ 70 mm (Typical)
• Weight: ≈ 2 g

Pinout and Wiring:

• Lead 1 (Input/Source): Connect this wire to the power source (AC line or DC positive) that feeds the load.
• Lead 2 (Output/Load): Connect this wire to the device or load you wish to protect (e.g., heating element, fan motor).
• Wiring Note: As a two-terminal switch, you must wire the KSD9700 in series with the load. It functions as an in-line thermal circuit breaker.
• Heat Transfer: Ensure the metal casing achieves secure thermal contact with the component or surface requiring temperature monitoring.

Datasheet Reference:

• Download KSD9700 Series Temperature Switch Datasheet

Commonly Used in:

• Power Supply Protection: Serving as an emergency thermal shutoff for transformers and power converters in industrial equipment.
• Battery Packs: Monitoring lithium-ion and other battery assemblies to prevent dangerous thermal runaway.
• Motors and Pumps: Protecting fractional horsepower motors and small submersible pumps from overheating due to excessive load or ventilation failure.

Applications:

• Heating Element Control: Use it to limit the maximum operational temperature of small heaters, soldering irons, and hot plates.
• LED Lighting Thermal Management: Preventing high-power LED arrays and drivers from overheating and failing prematurely.
• Home Appliances: Providing critical thermal safety cut-offs in coffee makers, electric blankets, rice cookers, and small ovens.

Equivalent Models:

• Klixon 3AP/4AP Series: Often used as industrial-grade equivalents with similar bimetallic thermal switch functionality and higher endurance.
• Microtherm RT Series: Another line of reliable snap-action thermal protectors offering various temperature and current ratings.
• T24-80C (Various Brands): Generic thermal switches rated for 80°C, offering similar protection in potentially different package form factors.
• KSD301 Series: A common alternative, though often found in a larger ceramic or plastic body, performing the same thermal cutoff function.

Package Includes:

• 1 x KSD9700 80°C Normally Closed (NC) Thermostatic Switch (5A 250V)