The part number A19AAB-26C is a Johnson Controls A19 Series Remote Bulb Temperature Control. It is a mechanical thermostat designed for high-range temperature applications, with a setpoint range of 100–240°F (38–116°C), a fixed 6°F differential, and a single-pole, single-throw (SPST) switch.

Specification & Description of A19AAB-26C

• Manufacturer/Brand: Johnson Controls (PENN Controls series)
• Part Type: Remote Bulb Mechanical Thermostat
• Switch Type: SPST (Single-Pole, Single-Throw) snap-acting switch
• Setpoint Range: 100–240°F (38–116°C)
• Differential: Fixed at 6°F
• Capillary Length: 6 feet
• Bulb Dimensions: 3/8" diameter x 3-1/2" length
• Enclosure: NEMA 1 (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).