Overview
The Johnson Controls A19ZBA is a proven single-stage temperature control designed for water chiller and refrigeration systems in commercial and industrial HVAC applications. This control unit regulates and monitors water chiller operation by using remote bulb temperature sensing to maintain precise cooling performance. The A19 Series is engineered for reliable operation in demanding cooling environments, providing consistent temperature management.
Key Features
- Single-stage heating or cooling with SPST (single pole, single throw) operation
- Remote liquid-filled bulb sensor with adjustable sensitivity
- Operates on 120 VAC or 240 VAC line voltage
- Adjustable differential control for precise temperature setpoint management
- LED indicator showing relay status and operational state
- Compact, space-efficient design suitable for retrofit applications
Technical Specifications
The A19ZBA-1C variant includes the following specifications:
- Temperature Range: 38–80°F (3–27°C)
- Adjustable Differential: 8–40°F (4–22°C)
- Switch Type: SPST (Single Pole, Single Throw)
- Action: Close High, Open Low
- Supply Voltage: 120 VAC or 240 VAC
- Sensing Element: Liquid-filled remote bulb with capillary
- Capillary Length: 6 feet standard
- Bulb Dimensions: 3/8-in. × 3-7/16 in.
- Control Type: Temperature actuated mechanical control
Typical Applications
- Centrifugal and screw chiller temperature regulation
- Commercial refrigeration systems and reach-in coolers
- Industrial water cooling circuits
- HVAC chilled water loop control
- Process cooling applications requiring precise temperature maintenance
- Retrofit replacement for legacy chiller controls
Compatibility & Replacements
Compatible With
- Commercial and industrial chiller units
- Water cooling tower systems
- Refrigeration condensing units
- Standard 120 VAC / 240 VAC line voltage systems
- Applications requiring remote bulb temperature sensing
Replaces / Drop-In Replacement For
- Johnson Controls A19 Series variants
- Verify compatibility with your system integrator before ordering for specific legacy model replacements
Works With
- Johnson Controls Penn Controls refrigeration product line
- Standard HVAC and refrigeration relay circuits
- Mechanical relay-based control systems
- Direct application to chiller solenoid valves and contactor circuits
