SBS-C3H8: Propane Gas Detector

Propane Sensor and Monitoring System

The SBS-C3H8 Propane Gas Detector is a propane gas detection system with visual and audible alarms and 25%LEL and 50%LEL propane relays.

The system comes complete with the main control, a highly accurate propane gas sensor and a 25 ft. cable. This unit can be powered with AC and/or DC power and can be mounted directly to a wall or to an electrical box, making it extremely versatile and very user-friendly.

The SBS-C3H8 includes relays for remote connection to alarm/monitoring systems and for control of external relays or an exhaust fan.



  • Protects life, property and company profits
  • Ideal for remote locations
  • Fail safe mode in event of loss of power
  • Up to three (3) sensors can be installed to main control to meet space coverage requirements


  • Universal power inputs: 110/220 Vac and/or 12–48 Vdc input
  • Strobe light for visual alerts
  • Sensor status indicator LEDs on the main control
  • Modular design for optimal placement of sensor(s)


  • Wall or 2-gang junction box mountable
  • Mechanical relays are easily accessible:
    • Warning 25% relay, 15 A @ 120 Vac; 10 A @ 277 Vac; 10 A @ 28 Vdc
    • Alarm 50% relay, 0.5 A resistive @ 28 Vdc, 0.5 A @ 125 Vac
  • Redundant power supply capability; dual AC and/or DC power supply connections (DC power supply will operate as backup power source)
  • Indicator LEDs can be tested by pushing the red “TEST” button
  • Sensors can be tested in the field with the P/N C3H8-TESTKIT

Detector can operate exhaust fans and building alarms / SCADA systems:

battery gas sensor diagram

Warning Settings: Should the concentration of propane gas in the air surrounding the sensor reach 25%LEL by volume, the “25%LEL Warning” yellow LED will light up on the main control of the unit. In addition, the 25%LEL internal relay will energize and can be used to activate an external exhaust fan.

Alarm Settings: Should the propane gas concentration reach 50%LEL by volume, the “50% Alarm” red LED will light up, the strobe will flash and an audible alarm will sound. In addition, the 50%LEL internal relay will energize and can be used to activate a building management/alarm system (via SCADA/Modbus).

SBS-C3H8 Includes

  • Main unit
  • Propane sensor
  • 25 ft. cable


Power Supply(s) 110/220 Vac, 50/60 Hz and/or
12–48 Vdc (9–58 Vdc operating voltage)
Leak Detection Propane
50% LEL (Lower Explosive Limit) Dry contacts rated 0.5A/28 Vdc
Dimensions 4.7" L x 4.7" W x 1.2" D (main control)

Parts & Accessories

N56 W16665 Ridgewood Dr. Menomonee Falls, WI 53051
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