STY6 series star point thermal switch

60°C – 200°C
3x AC 400V 2.5A … 6.3A
automatically resetting
Metal housing
Star point temperature switch

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Our STY6 series of thermal switches is characterized by innovative features and first-class quality. Thanks to direct star point switching, the STY6 series can be operated without relays or contactors, which simplifies installation and handling. With high sensitivity, excellent long-term stability and short bounce times, this star point thermoswitch provides reliable and precise temperature control.

The fixed silver contact and ceramic covers are riveted together, while the moving contact, bimetal disc and spring washer are connected by shaft pins. The moving contact is in close contact with the fixed silver contact under the bias pressure of the spring washer, creating a closed circuit.

The operation of the STY6 series star point thermoswitches is as follows: In normal operation, the movable contact and the fixed silver contact are in a closed state. As soon as the nominal operating temperature is reached, the bimetal washer is deformed by heat and the spring washer is pressed down by the riveted shaft pin. This causes the movable and fixed silver contacts to open abruptly. After the circuit is broken, the ambient temperature drops again. As soon as the defined reset temperature is reached, the bimetal disc snaps back to its initial position, the contacts close again, and the circuit returns to its normal operating state. By adding an additional external connection to the switch housing, the temperature switch can be used for three-phase applications, with the current flow for each phase interrupted during operation.

The STY6-U1 is a variant with the following specifications:

  • Normally closed (NC); reset automatically
  • With three connecting leads and epoxy resin insulation: Mylar-Nomex
  • Nominal switching temperature (NST) in 5K steps with tolerance of ±5K
  • Tolerance for reverse switching temperature (RST) ≥35°C (≤ 95°C NST) with tolerance of -50K±15K
  • Tolerance for RST (≥ 100°C ≤ 180°C NST) with tolerance of -65K±15K
  • Tolerance for RST (≥ 185°C ≤ 200°C NST) with tolerance of -85K±15K
  • Thickness: 6.6 mm
  • Diameter: 9.5 mm
  • Insulating cap length: 16 mm
  • Resistant to impregnation
  • Suitable for installation in protection class I + ll
  • Pressure resistance of the switch housing: 600N
  • Standard connection: 0.52 mm² / AWG20
  • Insulation voltage: 2.0 kV
  • Recognized standards: UL
  • Operating voltage range AC: up to 440 V AC
  • Rated voltage AC: 3x 400V 50/60Hz
  • Rated current AC cos ϕ = 1.0 /cycles: 2.5 A / 10,000
  • Maximum current AC cos ϕ = 1.0 /cycles: 6.3 A / 3,000
  • Total bounce time: < 1 ms
  • Contact resistance: ≤ 50 mΩ
  • Vibration resistance at 10 … 60 Hz: 100 m/s²

With various switching and reset temperatures available, the Alpha Therm STY6 star point thermal switch offers a customized solution for diverse applications. With its robust design and high-quality materials, it guarantees a long service life and optimum performance.