Johnson Controls P100AP-351 Encapsulated Pressure Control, Condenser Fan Cycling

Description

The Johnson Controls P100AP-351 is a direct-mount, encapsulated pressure control engineered specifically for condenser fan cycling applications in commercial and residential HVAC systems. With its open construction design and automatic reset functionality, this control delivers reliable, repeatable performance season after season.

How It Works

The P100AP-351 operates as a Single-Pole Single-Throw (SPST) switch that opens on a pressure drop. When system pressure falls to 75 PSIG, the contacts open, de-energizing the condenser fan motor. As pressure recovers and climbs back to 120 PSIG, the contacts automatically close, restarting the fan — maintaining optimal head pressure and system efficiency without manual intervention.

Key Features

• Direct-mount design for simplified installation on refrigerant lines or compressor ports
• Encapsulated construction protects internal components from moisture and contaminants
• SPST switching action — opens on pressure drop for condenser fan cycling control
• Automatic reset eliminates the need for manual restart after pressure recovery
• Open at 75 PSIG / Close at 120 PSIG setpoints optimized for condenser fan cycling
• 120/240 Vac contact ratings for broad compatibility with single- and dual-voltage fan motor circuits
• Open construction for easy field inspection and wiring access

Specifications

• Model: P100AP-351
• Brand: Johnson Controls
• Switch Type: SPST (Single-Pole Single-Throw)
• Operation: Opens on Pressure Drop
• Cut-Out (Open) Pressure: 75 PSIG
• Cut-In (Close) Pressure: 120 PSIG
• Contact Voltage Rating: 120/240 Vac
• Mounting: Direct Mount
• Construction: Open / Encapsulated
• Reset: Automatic
• Application: Condenser Fan Cycling

Application

Designed for condenser fan cycling duty, the P100AP-351 is the go-to choice for HVAC technicians managing head pressure control in air-cooled condensing units. By cycling the condenser fan in response to refrigerant pressure, it prevents low head pressure conditions during cold ambient operation, protecting compressors and maintaining system efficiency across a wide range of outdoor temperatures.