Thermal protectors

Thermal switches or temperature switches used for safe and repeated opening or closing of circuits.

They usually consist of a bimetal, a spring washer, a plastic, ceramic or metal housing, a (insulation) and pigtails or wires. When the nominal switching temperature reached due to rising ambient temperature or increased current (only current-sensitive), the bimetal disc snaps into its reverse position. This opens or closes the contact system and thus interrupts or contacts the electrical circuit. Depending on the version of the bimetallic switch, an automatic or manual reset occurs after cooling. For temperature switches with electrical latching (with PTC), the power supply must be disconnected before switching back.


Download Overview Thermal Switches

UK Series


  • AC 250V / 2A
  • 50°C...145°C
  • NC
  • Automatic reset
  • Plastic case
  • Solid or Stranded wire
Thermoschalter UK Serie

BW-D Series


  • AC 250V / 6A
  • DC 24V / 5A
  • 40°C...145°C
  • NC or NO
  • Automatic reset
  • Plastic- or insulated metal case
  • Solid or Stranded wire
  • Flat design (3mm)
Thermoschalter UK Serie

ST06 U1 Series


  • AC 250V / 10A
  • 60°C..180°C
  • NC or NO
  • Automatic reset
  • With shrink cap insulation
  • Stranded wire
  • Pressure resistant

ST01 U2 Series


  • AC 250V / 5A
  • 60°C...180°C
  • NC or NO
  • Automatic reset
  • Without insulation
  • Stranded wire
  • Pressure resistant

ST01 U3 Series


  • AC 250V / 5A
  • 60°C...180°C
  • NC or NO
  • Automatic reset
  • Without insulation
  • Without wire
  • Pressure resistant
  • Clamping contact

ST01 U4 Series


  • AC 250V / 5A
  • 60°C...150°C
  • NC or NO
  • Automatic reset
  • Epoxy insulation
  • Stranded wire
  • Pressure resistant

ST01 U5 Series


  • AC 250V / 5A
  • 60°C...180°C
  • NC or NO
  • Automatic reset
  • With transparent shrink cap insulation
  • Stranded wire
  • Pressure resistant

ST01 U6 Series


  • AC 250V / 5A
  • 60°C...180°C
  • NC or NO
  • Automatic reset
  • Plastic case
  • Stranded wire
  • Pressure resistant
  • Screw-on mounting

ST01 U7 Series


  • AC 250V / 5A
  • 60°C...180°C
  • NC or NO
  • Automatic reset
  • Insulated thread case
  • Stranded wire
  • Pressure resistant
  • With M4 x 6mm thread

ST01 U9 Series


  • AC 250V / 5A
  • 60°C...180°C
  • NC or NO
  • Automatic reset
  • Plastic case
  • Stranded wire
  • Pressure resistant

ST01 U8 Series


  • AC 250V / 5A
  • 60°C...180°C
  • NC or NO
  • Automatic reset
  • Plastic case
  • Solid wire
  • For PCB-mounting
  • THT-Pitch 5,08mm

Q Series


  • AC 250V / 2,5A
  • 40°C...150°C
  • NC
  • Electric self-holding
  • Plastic case
  • Solid or Stranded wire
Thermoschalter UK Serie

B12 Series


  • AC 250V / 10A (max. 30A)
  • 70°C...190°C
  • NC or NO
  • Automatic reset
  • Sintered
  • Stranded wire

Mounting Bracket


  • For mounting of the UK Series, ST-22 Series, BW-D Series,
    Q Series and much more
  • Spring steel
  • 3,5mm hole
  • Drummed and hardened
  • Thick layer passivated

ST01 U1 Series


  • AC 250V / 5A
  • 60°C...180°C
  • NC or NO
  • Automatic reset
  • With shrink cap insulation
  • Stranded wire
  • Pressure resistant

ST06 U2 Series


  • AC 250V / 10A
  • 60°C..180°C
  • NC or NO
  • Automatic reset
  • Without insulation
  • Stranded wire
  • Pressure resistant

ST-22 Series


  • AC 250V / 7A
  • DC 48V / 3A
  • 50°C...145°C
  • Öffner
  • Automatic reset
  • Plastic case
  • Solid or Stranded wire
Thermoschalter UK Serie

BW-C Series


  • AC 250V / 2A
  • DC 24V / 3A
  • 30°C...150°C
  • Current sensitive
  • NC or NO
  • Automatic reset
  • Plastic case
  • Stranded wire
  • Very flat design (2,4mm)
Thermoschalter UK Serie

ST07  Series


  • AC 250V / 10A
  • AC 120V / 22A
  • DC 16V / 20A
  • 55°C ... 180°C
  • NC
  • Automatic reset
  • Overload protection caused by current sensitivity
  • axial or radial design


α Therm


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safety components, sensor elements or sensors

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