Type series D switches are based on a complex system consisting of a contact spring unit and a thermo-bimetal snap-disc. When heating up to the fixed switching point, the contact opens, and thus interrupts the power circuit.

They are very flexible to use: Due to the different types of reset, and the adjustable current sensitivity for rapid shutdowns, the D switches offer a very good solution, especially in very specific safety concepts.

Temperature monitor with an automatic reset D10: After a certain cooling phase (temp. hysteresis) the contact switches back automatically.

Temperature limiter with a manual reset D20: After opening the contacts, and the subsequent cooling the contacts remain open until a manual reset is performed on the reset pin.

Temperature monitor with electr. self-retaining D30 (230V) / D40 (120V): After opening the contacts the switch is heated by a parallel connected resistor, and thus kept open. The automatic reset is only performed through a mains disconnection, or off-switching of the device in which the temperature monitor is installed.

• Combination of temperature and current sensitivity with the option to set a trigger time
• Switching current up to 16A
• semi-open or closed housing
• Applications in motors as current sensors
• Design is possible with cables and plugs

• Thermal motor protection
• Controller
• Limiter
• Safety switch

• Domestic appliances
• Washing machines
• Pumps
• Cooking devices
• Vacuum cleaners
• Automobile: Wiper motors, window lifter motors, electr. seating position