Johnson Controls P72DA-1C Penn Series P72 Standard Electromechanical Pressure Control

1. 서론

The Johnson Controls P72DA-1C Penn Series P72 Electromechanical Pressure Control is designed for high-pressure applications, primarily serving as a high-pressure cut-out control, head-pressure control, and for condenser fan cycling in commercial refrigeration and air conditioning systems. This control is compatible with most common refrigerants and can also be utilized in other non-corrosive fluid applications. Ammonia-compatible models are also available.

Key features of the P72DA-1C include:

• 전체 강철 케이스 및 커버: 까다로운 환경에서도 내구성을 보장하며, 내부 구성품에 대한 오래 지속되고 견고한 보호 기능을 제공합니다.
• 시력 설정 교정 압력 조정: Allows for visible pressure scale adjustment, fully adjustable through the range without removing the cover (on NEMA 1 enclosure models), simplifying setup.
• 수동 재설정 잠금 옵션: Features a trip-free lockout that prevents overriding or resetting until pressure returns to the specified safe level, enhancing system safety.
• Variety of pressure connection styles: Offers greater flexibility during mounting and when adapting pressure connections to various field application requirements.

The P72DA-1C model provides direct control of 208-240 volt single-phase motors up to 3 horsepower, and 208-220 volt 3-phase motors up to 5 horsepower.

2. 제품 오버view

그림 2.1: 전면 view of the P72DA-1C pressure control unit, displaying the pressure adjustment scale and the manual reset button.

Figure 2.2: Packaging for the Johnson Controls P72DA-1C, indicating the model number and basic specifications.

The P72DA-1C is an electromechanical pressure control featuring a durable all-steel case. It includes a visible pressure scale for easy adjustment and a manual reset lockout mechanism for safety. The unit is designed for robust performance in industrial and commercial HVAC applications.

3. 안전 정보

Always adhere to local and national electrical codes and regulations when installing and servicing this device. Failure to do so may result in property damage, personal injury, or death.

• Disconnect all power to the system before installation or servicing to prevent electrical shock.
• Ensure proper grounding of the control unit.
• 제어 장치의 지정된 전기 정격 용량을 초과하지 마십시오.
• Verify that the pressure range of the control matches the system requirements.
• 자격을 갖춘 인력만이 이 장비를 설치, 작동, 유지관리해야 합니다.

4. 설치

4.1 장착

1. Select a mounting location that is free from excessive vibration, moisture, and extreme temperatures.
2. Mount the control securely using appropriate fasteners. The unit can be wall-mounted.
3. Ensure adequate clearance for wiring and pressure line connections, as well as for accessing the adjustment and reset mechanisms.

4.2 전기 배선

1. Turn off all power to the system at the main disconnect.
2. Remove the control cover to access the wiring terminals.
3. Connect the power supply and load wires to the appropriate DPST (Double Pole, Single Throw) terminals as per the system's electrical schematic. Refer to the wiring diagram provided with the product for specific connections.
4. 모든 연결이 단단하고 안전한지 확인하세요.
5. Replace the control cover.

4.3 압력 연결

1. Connect the 36-inch capillary tube with the 1/4-inch flare nut to the system's high-pressure line.
2. Use appropriate tools to tighten the flare nut, ensuring a leak-free connection. Do not overtighten.
3. Verify that the capillary tube is routed to avoid kinks or sharp bends that could impede pressure transmission.

5. 운영

5.1 압력 설정

1. With the system powered off, remove the control cover (if applicable for your model) to access the sight-set calibrated pressure adjustment.
2. Rotate the adjustment screw or knob to set the desired high-pressure cut-out point. The visible scale will indicate the set pressure.
3. Ensure the set point is within the operating range of 50-500 psi and appropriate for your system's design.
4. Replace the control cover.

5.2 수동 재설정 잠금

The P72DA-1C features a manual reset lockout. If the system pressure exceeds the set high-pressure cut-out point, the control will trip and lock out, interrupting the circuit. To reset the control:

1. Identify and rectify the cause of the high-pressure condition.
2. Ensure the system pressure has returned to a safe operating level, below the lockout threshold.
3. 를 누르세요