BSDP3 – 3-PHASE FAILSAFE LIMITER 30A – for industrial water heating applications

This product is part of CAPILLARY CONTROLS


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



  • Combined control and safety function
  • Failsafe safety capillary
  • Independent non self resetting safety
  • Guarantee of safety operation : failsafe capillary
  • Available as single control or safety only
  • Double pole single throw version (DPST)
  • Multiple mounting, electrical connection, adjustment, and reset knob configurations
  • 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, liquid expansion in a separate bulb capillary assembly will break independent contacts to insure safety operation. The limiter is manually resettable.

Technical characteristics
  • BSDP
Type 30A triple pole single throw (TPST) adjustable or fixed temperature control with 3-pole safety limiter
Temperature range -35 to 300°C / -31°F to 572°C
Safety limiter function 70 - 125°C / 158 - 257°F
Rating 30A - 240V / 20A - 400V
Material Copper, stainless steel
Capillary length Up to 2000mm / Up to 79"
Safety limiter capillary Spiralled or single / double / triple bent capillary
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