Description
The Johnson Controls A19ADB-1 is a heavy-duty mechanical remote bulb temperature control engineered for reliable high-limit protection and precise temperature management across a broad range of commercial and industrial HVAC applications. Featuring a manual reset safety mechanism, this controller ensures that the system remains off after a high-temperature trip event until an operator manually restores operation — providing an added layer of protection against equipment damage or unsafe conditions.
Key Features
- Wide voltage compatibility: 24 to 277Vac for versatile system integration
- SPST (Single-Pole, Single-Throw) switching action — Open on temperature rise (Open High)
- Manual reset operation for positive high-limit safety control
- Broad setpoint range: 100°F to 240°F to suit diverse process and HVAC applications
- 6-foot capillary length for flexible remote sensing installation
- 3/8″ x 3½” sensing bulb for accurate, responsive temperature detection
- Knob range adjuster for convenient, tool-free setpoint changes
- Mechanical (non-electronic) design for proven, long-term reliability
Specifications
- SKU / Part Number: A19ADB-1
- Brand: Johnson Controls
- Control Type: Mechanical Remote Bulb Temperature Control
- Voltage Range: 24 to 277Vac
- Switch Action: SPST, Open on Rise (Open High)
- Reset Type: Manual Reset
- Setpoint Range: 100°F to 240°F
- Capillary Length: 6 feet
- Sensing Bulb Size: 3/8″ diameter x 3½” length
- Setpoint Adjustment: Knob Range Adjuster
Applications
- High-limit temperature protection in commercial HVAC systems
- Duct and plenum temperature monitoring
- Boiler and hydronic heating safety controls
- Industrial process temperature control
- Air handling unit (AHU) high-temperature cutout
Why Choose the Johnson Controls A19ADB-1?
The A19ADB-1 delivers the dependability and flexibility that HVAC professionals demand. Its wide voltage range eliminates compatibility concerns across most commercial control circuits, while the generous 6-foot capillary and compact sensing bulb allow installation in tight or remote locations. The manual reset feature ensures that any high-temperature fault condition requires deliberate operator intervention before the system resumes — a critical safety advantage in high-value or sensitive equipment environments. The intuitive knob adjuster makes setpoint changes fast and straightforward without the need for additional tools.
