CPCE 12 (034N0082) Danfoss Hot Gas Bypass Regulator

Product Overview

The CPCE 12 (034N0082) is a high-performance hot gas bypass regulator designed to adapt compressor capacity to actual evaporator load. By bypassing hot gas from the high-pressure side of the refrigeration system to the low-pressure side (typically between the expansion valve and the evaporator), the Danfoss 034N0082 (034N0082) ensures a minimum suction pressure is maintained. This prevents the evaporator from freezing and avoids the compressor from "short-cycling" during low-load conditions. This regulator is a critical component for B2B industrial refrigeration and air conditioning systems where precise temperature control and compressor longevity are primary operational goals.

Technical Configuration

The CPCE 12 is engineered for indirect bypass applications, often used in conjunction with a liquid-gas mixer (LG type) to ensure efficient mixing and prevent high suction gas temperatures. It features a precision-calibrated 13.5 mm actuator system that reacts to suction pressure changes. The internal mechanism is built to withstand extreme environments, operating reliably in ambient temperatures as low as -40 Celsius. The regulator is constructed with a hermetic design to minimize leak potential and is rated for a Maximum Working Pressure (PS) of 18 bar (260 psig). Its robust build quality makes it suitable for various fluorinated refrigerants (HCFC/HFC), ensuring versatility across diverse cooling architectures.

Technical Specifications

Technical FAQs

How does the CPCE 12 prevent evaporator icing?

When the evaporator load drops, the suction pressure decreases. The CPCE 12 senses this drop and opens to bypass hot gas into the evaporator inlet, effectively "faking" a load to keep the suction pressure above the freezing point of the coil.

Is an LG mixer required when using the 034N0082?

While not strictly mandatory for the regulator to function, using a Danfoss LG liquid-gas mixer is highly recommended. It ensures that the bypassed hot gas and the liquid refrigerant from the expansion valve are mixed thoroughly, protecting the compressor from overheating.

Can the setpoint of the CPCE 12 be adjusted in the field?

Yes, the regulator features an adjustment screw that allows technicians to set the specific suction pressure at which the bypass begins to open, allowing for fine-tuning based on the specific requirements of the refrigeration loop.

Engineering & Installation Guide

• Piping Integration: The CPCE 12 should be installed in a bypass line between the compressor discharge line and the evaporator inlet. Ensure the flow direction follows the arrow on the valve body. To protect the regulator from debris, a filter drier should be installed in the system.

• Thermal Management during Soldering: Use a wet cloth to wrap the regulator body during the soldering process. The internal components are sensitive to high heat; maintaining the body temperature below 100 Celsius is vital to prevent diaphragm damage and setpoint drift.

• Startup Calibration: During system commissioning, slowly turn the adjustment screw while monitoring the suction pressure gauge. One full turn typically changes the pressure setting by approximately 0.2 to 0.3 bar. Adjust until the regulator opens just as the suction pressure reaches the minimum safe limit for your specific application.