BSD – BIMETAL SAFETY – for industrial water heating applications

This product is part of CAPILLARY CONTROLS
Relevant applications:


Oil boiler thermostat. 3-phase temperature regulation and bimetal safety limiter with manual reset



  • Combined control and safety function
  • Multiple mounting
  • Factory pre-set fixed temperature, OEM adjustable or end-user adjustable temperature



A rise in temperature causes the expansion of liquid within the bulb and capillary. The liquid acts on a bellows assembly within the plastic housing to open and close electrical contacts with temperature variation. In case of abnormal rise in temperature, bimetal safety will break independent contacts to insure safety operation. The limiter is manually resettable.


Technical characteristics
  • BSD
Type Triple pole single throw
Temperature range -10 to 120°C / 14 to 248°F
Safety limiter function Bimetal : 70 to 120°C / 70 to 248°F
Rating 15A - 400V / 20A - 240V
Material Copper
Capillary length Up to 2000mm / Up to 79"
Connections Brass or nickel plated faston terminals, screw terminals
Approvals CE conformity, ENEC mark according to EN-60730-1, EN 60730-2-9, ROHS conformity
Technical drawings