Model ISQA – Bimetal Thermostat

Bimetal Thermostat Models ISQA, ISQB and ISQC have been developed after extensive research and development by our engineering team to address the customers’ requirement of durability, rigidity of body and ease of mounting. These bimetal thermostats are the newest models in our range of products. Each bimetal thermostat has a solid machined aluminum body to provide greater strength. Due to the metal body, these bimetal thermostats have better heat sensing capability than ordinary thermal overload protectors.

Mounting Arrangements –

All the three models have different mounting arrangements to suit the customers’ needs.

    • Model ISQA has two holes at the end, by which it can be screwed on to any flat surface.
    • Model ISQB has two grooves, one on each end. It can also be mounted with two M3 screws.
    • Model ISQC has only one groove at the end, by which it can be screwed.

Bimetal Thermostat – Model ISQA

Snap Disc Thermostat – Model ISQB

Snap Action Thermostat- Model ISQC

The outer metal body of all these bimetal thermostats are electrically insulated, as there in inbuilt engineering polymer electrical insulation inside, and so there is no chance of any electrical shock. All the internal components are spot welded on a stainless steel housing plate. The operating principle of these thermal overload protectors are based on the over center mechanism which operate a snap action bimetal with a beryllium copper switching blade. This provides the bimetal thermostat with quick restart and stable trip temperature. The normal snap action disc thermostats are have delayed restart and the trip temperature drifts after long usage. The contacts are made of solid silver for long life. It is available with Normally Closed or Normally Open contacts. Due to the aluminum body, response to temperature rise is fast, and when the equipment overheats, the thermal overload protector will trip off, ensuring complete protection.

Special Features of Bimetal Thermostat:

      • Aluminum body for strength better heat sensing
      • Snap Action for quick make and break switching.
      • Chattering free and precise operating characteristics.
      • Solid silver contacts for long life.
      • Sealed body resistant to moisture, gases, fumes and varnish.
      • Lead wires are teflon insulated.
      • Available with Normally Open (N.O.) or Normally Closed (N.C) contacts
      • Available for any trip temperature required from 50C to 160C.

Technical Specifications

 Voltage Upto 250 VAC or 24 VDC
 Continuous Load Upto 8 AMPS
 Maximum Load Switching  Capacity 30 AMPS
 Switching Action SPST Normally Closed (N.C.) contacts which open with a snap action. Also available Normally Open (N.O.) contacts which close with a snap action.
 Flash-over Voltage Exceeds 2 KV between body & leads.
 Endurance (Life) Exceeds 100,000 operations (trippings).
 Trip Temperature Available preset for any trip temperature between 50 ± 5 C to 160 ± 5 C specified by customer. Not adjustable.
 Reset Temperature Reset temperature approx. 15 ± 5 C below trip temperature.
 Restart Mode Automatic restart upon cooling. Adequate precaution must be exercised in applications where automatic restart can cause injury, i.e., power tools, mixie blade, power saws, machinery etc.


    • Heating Moulds
    • Welding equipment & gas pre-heaters
    • Motor overheat & burnout protection – all sizes (single and three phase)
    • Oven Thermostats
    • Transformer overheat & burnout protection (all sizes)
    • Industrial electronics: overheat protection of thyristors, power transistors, SCRs, etc.
    • Industrial Machinery
    • Aluminum channel heat sink over-temperature sensor
    • Surface Heaters
    • Bearing and bushes overheat sensors

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