Johnson Controls P47AB-3 Limit Control

The Johnson Controls P47AB-3 is a heavy-duty steam pressure limit control designed for high-pressure boiler applications requiring a manual reset safety mechanism. This SPST controller features contacts that open on pressure rise, providing a critical fail-safe for commercial and industrial steam systems. Engineered for versatility, the P47AB-3 supports multi-voltage electrical ratings including 120, 208, 240, and 277 Vac, allowing for seamless integration into various control circuits. With an adjustable pressure range of 50 to 240 psig, it provides precise high-limit protection. This unit is a direct replacement for the P47AB-3C, sharing identical specifications and footprint. The bellows-actuated sensing element ensures long-term reliability in demanding environments. For technicians managing high-pressure steam boilers, this industrial pressure switch is the standard for preventing over-pressure conditions and ensuring code compliance within the mechanical room.

Key Benefits

• Manual Reset Security: Ensures the system remains offline for inspection if a high-limit trip occurs, preventing dangerous automatic cycling.
• Universal Voltage Compatibility: The 120/240 Vac electrical rating facilitates installation across different power configurations without extra transformers.
• High Pressure Capability: Specifically designed for high pressure steam systems with a robust 240 psig maximum setpoint.
• Proven Reliability: The P47 Series is a long-standing industry standard, known for its durable internal bellows and snap-acting switches.

Common Questions

Can the P47AB-3 be used for low-pressure steam applications?
No, this control is designed for high-pressure systems with a range starting at 50 psig. For low-pressure steam, a P47 series control with a lower range should be selected to ensure accuracy.

What is the difference between the P47AB-3 and the P47AB-3C?
There is no functional or technical difference between these models; the P47AB-3 and P47AB-3C are identical units and can be used interchangeably in the field.

Does this switch close or open on pressure rise?
This is an Open on Rise control. When the steam pressure reaches the high-limit setpoint, the SPST contacts open to break the burner or control circuit.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.