The part number A19ADB-1C is a Johnson Controls A19 Series Remote Bulb Temperature Control. It is a mechanical thermostat with SPDT switching, a manual reset, and a setpoint range of 100–240°F (38–116°C).

Specification & Description of A19ADB-1C

• Manufacturer/Brand: Johnson Controls (PENN Controls series)
• Part Type: Remote Bulb Temperature Control (mechanical thermostat)
• Switch Type: SPDT (Single-Pole, Double-Throw) snap-acting switch
• Reset Type: Manual reset (requires operator action after trip)
• Setpoint Range: 100–240°F (38–116°C)
• Differential: Constant throughout the range (non-adjustable)
• Voltage Rating: 24–600 VAC
• Bulb Dimensions: 3/8" diameter x 4" length
• Capillary Length: 8 feet
• Bulb Temperature Limit: Up to 290°F
• Enclosure: Compact NEMA 1 housing (general-purpose indoor use)
• Operation:
  • Uses a liquid-filled sensing bulb and capillary to detect temperature.
  • Provides snap-acting mechanical switching when the setpoint is reached.
  • Requires no external power (purely mechanical).