1. Introduction
This manual provides essential information for the proper installation, operation, and maintenance of the Danfoss TE2 Expansion Valve, model 068Z3209. This valve is designed for use with R22 and R407C refrigerants in various refrigeration applications, including traditional refrigeration, self-contained refrigerators, transport refrigeration, and supermarket refrigeration systems. Understanding the contents of this manual will ensure optimal performance and longevity of the valve.
2. Product Features
The Danfoss TE2 Expansion Valve incorporates several key features for reliable and efficient operation:
- Hermetic, Laser Welded Power Head: Features a non-replaceable stainless steel power head, hermetically sealed for durability and leak prevention.
- Laser Engraved Information: Product information is laser engraved for lasting identification of the valve type, ensuring clear readability throughout its lifespan.
- Functional Design: The valve's operation relies on a valve body and a separate orifice. Nominal capacity is determined by the selected orifice size, ranging from 1/4 to 5.5 tons.
- Flare Connections: Equipped with flare inlet, outlet, and equalization connections for secure and adaptable installation. Flare/solder adapters are available as additional accessories.
- Adjustable Superheat: Allows for precise superheat adjustments in 1/4 turn increments, with each 1/4 turn equating to approximately 1.75°F. Turning clockwise increases superheat, while turning counter-clockwise decreases it.
- Robust Capillary Tube and Sensing Bulb: Designed for reliable temperature sensing and control.
- Replaceable Orifice Assembly: Includes a dirt-protection filter to maintain system cleanliness and performance.
Image 1: Exploded view highlighting key features of the Danfoss TE2 Expansion Valve, including the robust stainless steel capillary tube, sensing bulb, laser-engraved information, hermetic power head, flare connections, adjustable superheat, and replaceable orifice assembly with dirt-protection filter.
3. Specifications
| Attribute | Value |
|---|---|
| Model Number | 068Z3209 |
| Refrigerants | R22, R407C |
| Equalization Type | External |
| Inlet Connection | 3/8 inch Flare |
| Outlet Connection | 1/2 inch Flare |
| Equalization Connection | 1/4 inch Flare |
| Capacity Range | 1/4 to 5.5 tons (dependent on orifice) |
| Material | Stainless Steel (power head), Brass (body) |
| Item Weight | 10.2 ounces (approx. 0.64 LBR) |
| Product Dimensions (L x W x H) | 3 x 3.5 x 2.75 inches |
| Number of Ports | 3 |
| Specification Met | CE |
4. Installation and Setup
Proper installation is crucial for the correct functioning of the expansion valve. It is recommended that installation be performed by a qualified refrigeration technician.
4.1 Orifice Selection
The valve's capacity is determined by the installed orifice. To select the correct orifice, use one of the following methods:
- System Characteristics: Select the orifice based on the appropriate refrigerant, evaporator temperature, and overall system capacity requirements.
- Nominal Capacity Matching: If replacing an existing valve, match the nominal capacity of the originally installed valve with the nominal capacity provided in the technical data chart (refer to Section 7). If an exact capacity cannot be found, select the next larger orifice.
4.2 Connection
- Ensure all connections are clean and free of debris.
- Connect the 3/8 inch flare inlet to the liquid line from the condenser/receiver.
- Connect the 1/2 inch flare outlet to the evaporator inlet.
- Connect the 1/4 inch flare equalization line to the suction line, downstream of the evaporator.
- Use appropriate flare tools and ensure connections are tightened to the manufacturer's recommended torque specifications to prevent leaks.
- If required, use flare/solder adapters (sold separately) for solder connections.
4.3 Sensing Bulb Placement
Mount the sensing bulb securely on the suction line, typically after the evaporator, to accurately measure the superheat. Ensure good thermal contact and insulate the bulb to prevent ambient temperature interference.
5. Operation
5.1 Superheat Adjustment
The superheat setting is critical for efficient evaporator operation and compressor protection. Adjustments should be made carefully and incrementally.
- Make superheat adjustments in 1/4 turn increments.
- Each 1/4 turn typically corresponds to a change of approximately 1.75°F in superheat.
- To increase superheat, turn the adjustment stem clockwise.
- To decrease superheat, turn the adjustment stem counter-clockwise.
- Allow sufficient time after each adjustment for the system to stabilize before making further changes.
6. Maintenance
The Danfoss TE2 Expansion Valve is designed for long-term reliability with minimal maintenance. However, periodic checks are recommended as part of overall system maintenance.
- Leak Detection: Regularly check all flare connections for refrigerant leaks using appropriate leak detection methods.
- Orifice Inspection: The replaceable orifice assembly includes a dirt-protection filter. If system performance degrades, inspect the orifice and filter for blockages or damage. Replace the orifice if necessary.
- Sensing Bulb Integrity: Ensure the sensing bulb remains securely attached and insulated on the suction line. Damage or improper insulation can affect superheat control.
- System Cleanliness: Maintain overall system cleanliness to prevent contaminants from affecting valve operation.
7. Technical Data and Ordering
The following table provides technical data for orifice selection and valve capacities for R22 and R407C refrigerants. Capacities are given in tons for various evaporator temperatures.
Image 2: Technical data table for T2 and TE2 valves, detailing orifice codes, nominal capacity in tons, and rated capacity in tons across evaporator temperatures from -40°F to +50°F for R-22 and R-407C.
Note: If the exact capacity required cannot be found in the table, always select the next larger orifice size to ensure adequate refrigerant flow.
8. Dimensions
Refer to the diagram below for the physical dimensions of the Danfoss TE2 Expansion Valve. All measurements are approximate and provided in both millimeters and inches.
Image 3: Dimensional drawing of the Danfoss TE2 Expansion Valve, showing overall length, width, height, and connection sizes (e.g., 35mm [1.4 in], 44mm [1.7 in], 31mm [1.2 in], 36mm [1.4 in] for the valve body, and 50mm [2.0 in] length, 14.5mm [0.6 in] diameter for the sensing bulb).
9. Troubleshooting
This section provides general guidance for common issues. For complex problems, consult a qualified refrigeration technician.
| Problem | Possible Cause | Solution |
|---|---|---|
| High Superheat | Insufficient refrigerant flow, incorrect orifice size, sensing bulb improperly installed/insulated, low refrigerant charge. | Decrease superheat setting (counter-clockwise), verify orifice selection, check sensing bulb placement and insulation, check system refrigerant charge. |
| Low Superheat / Liquid Floodback | Excessive refrigerant flow, incorrect orifice size, sensing bulb losing thermal contact, overcharged system. | Increase superheat setting (clockwise), verify orifice selection, ensure sensing bulb has good thermal contact and insulation, check system refrigerant charge. |
| Fluctuating Superheat | Unstable system conditions, sensing bulb not properly insulated, external equalization line blocked. | Stabilize system load, insulate sensing bulb, check equalization line for obstructions. |
| Reduced Cooling Capacity | Incorrect orifice size, clogged orifice/filter, low refrigerant charge, other system issues. | Verify orifice selection, inspect and clean/replace orifice and dirt-protection filter, check system refrigerant charge, diagnose other system components. |
10. Warranty and Support
For information regarding product warranty, technical support, or to locate authorized service centers, please refer to the official Danfoss website or contact your local Danfoss distributor. Ensure you have your product model number (068Z3209) available when seeking support.
Danfoss Website: www.danfoss.com
