Johnson Controls P-3800-1 Controller

The Johnson Controls P-3800-1 Reset Volume Controller is a high-performance, pressure-independent submaster device engineered to regulate airflow within Variable Air Volume (VAV) systems. Designed for precision, this pneumatic airflow controller operates with a supply pressure range of 13-25 PSIG and delivers an output pressure of less than 2 PSIG. It is built to maintain a constant reset span, which effectively eliminates hunting and ensures stable zone comfort even during static pressure fluctuations. This unit features 3/8" barbed fitting air connections for Inputs I and II and consumes only 25 SCIM of air, making it an efficient choice for large-scale HVAC pneumatic controls. The P-3800-1 controller highlights an isolated diaphragm design, allowing for versatility in sensing line lengths without compromising accuracy. Factory-calibrated with an 8 PSIG reset start point, this robust component is essential for technicians seeking reliable VAV box volume control in both heating and cooling applications.

• Pressure Independent Operation: Maintains precise airflow volume regardless of fluctuations in system static pressure.
• Precise Low-Velocity Control: Capable of managing flow down to 0.01 in. WG velocity pressure for demanding technical specifications.
• Adjustable Configuration: Features fully adjustable reset start points and ranges to match specific system drawings and field requirements.
• Contamination Protection: Incorporates a replaceable filter/orifice assembly to prevent system down-time due to air supply oil contamination.
• Universal Compatibility: Designed to interface seamlessly with direct acting thermostats and various master controllers in HVACR environments.

How do I adjust the reset range on the P-3800-1?
The reset range is adjusted using the slider on the side of the unit. Loosen the locking screw and move the slider to your required velocity pressure range, typically determined by the VAV box schedule, then re-tighten to secure the setting.

Can this controller be used for both heating and cooling?
Yes, the P-3800-1 is compatible with various VAV configurations. Since this model is often paired with direct-acting thermostats, ensure your sequence of operation matches the pneumatic logic of the controller for proper damper positioning.

What should I do if the controller output becomes sluggish?
Sluggish response often indicates a clogged internal orifice. This unit features a field-replaceable filter/orifice assembly (Part P-3800-600), which allows for quick restoration of performance without replacing the entire controller.

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.