ST06 U4 series

60°C – 155°C
AC 250V 10A
automatically resetting
Metal housing with epoxy coating

Download PDF

Product description ST06 U4

The ST06 U4 belongs to the ST06 series with a power class from 6.3 A to 25 A. It is closed as standard, has an automatic reset and is equipped with connection cables and blue epoxy resin insulation.


The ST06 U4 consists of a robust construction with a ceramic cover plate for the fixed silver contact. The movable contact is welded to a cross-shaped spring washer, which is connected to a conductive housing.


In normal operation, the movable contact is in close contact with the fixed silver contact under the preload of the spring washer. When the rated operating temperature is reached, the bimetallic disk is deformed by heat and causes the contact to open suddenly. This interrupts the circuit and protects the appliance from overheating.

After the circuit has been interrupted, the ambient temperature begins to drop. As soon as the defined reset temperature is reached, the bimetal disk and the spring washer return to their initial position. This closes the moving contact and the fixed silver contact again and the circuit is re-established.


  • Rated current class: 6.3 A to 25 A
  • Closed as standard for safe operation
  • Connection cable for easy installation
  • Robust blue epoxy resin insulation for high reliability
  • Integrated ceramic cover plate protects the fixed silver contact
  • Suitable for a wide range of industrial applications