SKU: SENS-3548
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KSD9700/BK05-BB1D Metallic Shell Temperature Control Switch - 5A 250V, 135C NC

₹21.00 (Inclusive of all taxes)
Out of Stock

The KSD9700/BK05-BB1D is a metallic-shell, snap-action thermal switch designed for over-temperature protection in appliances, power supplies, and motor controls. It features a normally closed (NC) contact that opens at a calibrated 135°C, rated for 5A at 250V AC/DC, with a 7cm lead wire for easy integration.

Features

  • Metallic shell bimetallic snap-action thermostat with 135°C normally closed (NC) set point.
  • Rated for 5A at 250V AC/DC, suitable for direct switching of small motors, heaters, and transformers.
  • Compact dimensions (approx. 20mm x 8mm x 4mm) with 7cm insulated lead wires for simplified wiring.
  • Designed for reliable over-temperature cut-off in appliances, power tools, and industrial controls.
  • Mechanical operation requires no external power, ensuring fail-safe protection even during power loss.

Out of stock

Description

The KSD9700/BK05-BB1D is a bimetallic disc thermostat housed in a metallic shell for robust thermal conduction and mechanical durability. Its operation is based on the differential expansion of bonded metals: upon reaching the calibrated trip temperature (135°C), the disc snaps to open the normally closed contacts, interrupting the circuit to prevent overheating. After cooling below the reset temperature, the contacts automatically re-close, restoring operation.

This switch is engineered for direct series connection in the load circuit, providing a simple, cost-effective, and maintenance-free solution for thermal protection. The metallic housing ensures rapid response to ambient temperature changes, making it ideal for embedding in motor windings, transformer cores, or mounting on heat sinks within power electronics, small appliances, and battery charging systems.

Key Features

  • Bimetallic snap-action mechanism for precise, repeatable temperature switching at 135°C.
  • Robust metallic shell construction for excellent thermal conductivity and mechanical strength.
  • 5A @ 250V AC/DC contact rating enables direct control of significant loads without a relay.
  • Normally closed (NC) contact configuration provides fail-safe circuit interruption on over-temperature.
  • Pre-attached 7cm insulated wire leads simplify installation and soldering.
  • Compact form factor (approx. 20mm x 8mm x 4mm) allows for installation in space-constrained designs.
  • Wide operating temperature range up to 110°C ambient, suitable for demanding environments.
  • High-value build offering reliable protection for motors, transformers, and heating elements.

Applications

  • Over-temperature protection for AC/DC motor windings in power tools, fans, and pumps.
  • Thermal cut-off safety device in switching power supplies, battery chargers, and transformers.
  • Temperature control and safety interlock in small household appliances like coffee makers, soldering irons, and hair dryers.
  • Embedded thermal protection within LED drivers and power electronic modules.
  • Industrial control panel component cooling fan activation or heater cut-off.

Technical Specifications

Manufacturer Part NumberKSD9700/BK05-BB1D
Product TypeThermal Switch / Thermostat
Switch ConfigurationNormally Closed (NC)
Trip Temperature (Set Point)135 °C
Rated Voltage250 V AC/DC
Rated Current5 A
Operating Temperature RangeUp to 110 °C (Ambient)
Housing MaterialMetallic Shell
Cable / Lead Length7 cm
Head Dimensions (Approx.)20 mm x 8 mm x 4 mm
Shipping Weight0.03 kg

Frequently Asked Questions

What is the set (trip) temperature and reset temperature for this KSD9700 switch?

The KSD9700/BK05-BB1D model has a calibrated trip temperature of 135°C, where the normally closed contacts snap open. The reset temperature, when the contacts re-close, is typically 15-25°C lower than the trip point, around 110-120°C, depending on the specific bimetallic calibration. This hysteresis is inherent to the mechanical design.

Can this thermal switch be used to directly control a 120V AC appliance drawing 3A?

Yes, absolutely. With a rating of 5A at 250V AC, this switch is well-suited for directly switching a 120V AC, 3A load like a small heater or motor. The contacts are designed for AC/DC operation. Ensure the switch is wired in series with the load's live (hot) wire and mounted in good thermal contact with the component being protected.

How should I mount and wire the KSD9700 thermostat for optimal performance?

For accurate sensing, the metallic shell must be in direct, firm thermal contact with the heat source (e.g., motor housing, heat sink) using thermal adhesive or a mounting clip. The two 7cm wire leads are not polarized; connect them in series with the load circuit you wish to interrupt. Avoid stressing the leads mechanically and ensure no insulation is melted by nearby hot components.

Is this a manual reset or automatic reset thermostat?

This is an automatic reset (auto-reset) thermostat. Once the temperature falls below the reset point after a trip event, the bimetallic disc will snap back, automatically closing the contacts to restore circuit continuity. No manual intervention is required, making it ideal for unattended or embedded protection applications.

Package Includes

  • 1 x KSD9700/BK05-BB1D Metallic Shell Temperature Control Switch (5A 250V, 135C NC)

Additional Information

Weight 0.03 kg
Dimensions 9 × 7 × 1 cm