Installation and Specifications of High Voltage Elbow Connectors for Medium and High Voltage Applications

High voltage elbow connectors are essential components in electrical distribution systems, serving as terminations for medium and high voltage cables. These connectors provide safe and efficient connections in applications such as transformers, switchgear, and motor installations. This article explores the installation processes and technical specifications of two types of elbow connectors: the 600 Amp T-Body elbow and the Euromold 158LR elbow. The discussion is based on information provided by manufacturer documentation and installation guides, ensuring adherence to technical accuracy and safety standards.

Technical Specifications and Applications

High voltage elbow connectors are categorized by their voltage ratings, current capacities, and compatibility with different types of cables. The 600 Amp T-Body elbow is designed for deadbreak applications and is typically used to connect padmount transformers to the electrical grid. It is commonly employed in radial or loop feed systems and requires specific tools and procedures for proper installation.

The Euromold 158LR elbow, on the other hand, is a separable connector that terminates medium to high voltage cables (up to 24kV) and connects them to Interface A bushings. It is suitable for both indoor and outdoor applications and is designed to handle conductor cross-sections ranging from 16 to 95 square millimeters. The 158LR is a dead-break connector and is not suitable for load-break operations.

Both connectors are used in power distribution systems where safety, reliability, and compatibility with specific cable types are critical. They are commonly found in power transformers, switchgear, and other high-voltage equipment, where proper installation and maintenance are crucial for system performance.

Installation Process for 600 Amp T-Body Elbow

The installation of a 600 Amp T-Body elbow involves a series of steps that ensure a secure and reliable connection. According to manufacturer instructions, the process begins with inspecting the padmount transformer’s bushings to determine whether the system is set up for a loop or radial feed. In a loop feed system, arresters may be required on unused bushings to protect the equipment from lightning and switching surges.

Tools Required

The following tools are necessary for the installation of a 600 Amp T-Body elbow:

• Marker
• Cable scoring tool
• Ruler
• Elbow kits
• Pliers
• Mastic tape
• Electrical tape
• Cable cutter
• Wire brush
• Lug crimp
• Torque wrench
• Power drill
• Cable cleaner
• Jacket removing tool

These tools are used to prepare the cable, clean the bushing, and secure the elbow termination.

Step-by-Step Installation

1. Inspection and Preparation: Open the primary side of the padmount and inspect the bushings. If the system is a loop feed, ensure that arresters are installed on unused bushings for protection against electrical surges.

2. Cable Preparation: Use a cable scoring tool and jacket removing tool to strip the insulation from the cable. Clean the exposed conductor and semi-conductive screen using a wire brush and cable cleaner.

3. Applying Silicone: Apply silicone to the plastic around the bushing insert to ensure a secure seal. Avoid applying silicone directly to the stud to prevent interference with the connection.

4. Attaching the T-Body: Place the T-Body on the transformer bushing, ensuring that the connector lies flat against the surface. Align the stud with the lug and apply silicone to the inside rim of the T-Body before adding the cap.

5. Torquing the Connection: Torque the T-Body to the specified pressure (typically 55 foot pounds for 25kV T-Bodies). Improper torquing is a leading cause of elbow termination failure.

6. Alternative Installation for Arresters: If arresters are required, use a 200 Amp reducing tap plug instead of a T-Body cover. Clean the adapter, apply silicone, and install it into the 600 Amp T-Body. Secure the adapter with an allen wrench and add an arrester or insulating cap.

7. Final Checks: After installation, verify that all components are securely fastened and that the connection is free from debris or damage.

The installation of a 600 Amp T-Body elbow requires careful attention to detail and adherence to manufacturer guidelines. Any deviation from the specified procedures may compromise the integrity of the connection and lead to system failures.

Technical Details and Installation of Euromold 158LR Elbow

The Euromold 158LR elbow is a dead-break separable connector that terminates medium to high voltage cables and connects them to Interface A bushings. It is designed for use with polymeric insulated cables and is suitable for conductor cross-sections ranging from 16 to 95 square millimeters. The 158LR is available in both 11kV and 24kV configurations and is compatible with copper wire screen and copper tape screen cables.

Key Specifications

The following are key specifications for the Euromold 158LR elbow:

• Current Rating: 250A (Interface A Bushings)
• Voltage Classes: 11kV, 12kV, and 24kV
• Conductor Cross Section Sizes: 16 to 95 square millimeters
• Core Insulation Diameter Range: 12.6 to 26.4 mm
• Applications: MV HV switchgear, transformers, and motors
• Cable Types: XLPE and EPR insulated cables
• Screen Types: Copper wire screen or copper tape screen

The 158LR elbow is supplied with a complete kit that includes cable lubricant, wipers, installation instructions, and a crimp chart. It is essential to use the correct part number based on the cable's core insulation diameter and conductor size to ensure a proper fit.

Installation Process

The installation of the Euromold 158LR elbow requires the following steps:

1. Cable Preparation: Strip the cable's insulation and semi-conductive screen using a jacket removing tool and wire brush. Ensure that the conductor is clean and free from semi-conductive residue.

2. Cleaning the Bushing: Clean the bushing using cable cleaning wipes, wiping in the direction of the copper screen wires to remove any residue.

3. Applying Lubricant: Apply cable lubricant to the core insulation to facilitate a smooth connection.

4. Inserting the Elbow: Insert the Euromold 158LR elbow into the bushing, ensuring that it is aligned correctly. The conductive EPDM insert and insulating layer provide a safe and secure connection.

5. Securing the Connection: Use the crimp chart to determine the appropriate crimp size based on the conductor size. Crimp the connector using a lug crimp tool and ensure that the connection is secure.

6. Earthing and Accessories: For copper tape screen cables, use a copper tape screen earthing kit to ensure a proper ground connection. Additional accessories such as dead-end receptacles and earthing plugs may be required depending on the application.

7. Final Inspection: After installation, inspect the connector for any signs of damage or misalignment. Ensure that all components are securely fastened and that the connection meets the required specifications.

The Euromold 158LR elbow is designed for use by qualified personnel who are trained in high voltage electrical equipment installation. Proper installation is critical to ensure the safety and reliability of the connection.

Compatibility and Selection Guidelines

Selecting the correct elbow connector is essential to ensure compatibility with the cable type, conductor size, and voltage rating. The 600 Amp T-Body elbow is suitable for deadbreak applications and is commonly used in radial or loop feed systems. It is compatible with copper and aluminum conductors and requires a specific torque specification to ensure a secure connection.

The Euromold 158LR elbow is available in multiple configurations to accommodate different conductor sizes and voltage ratings. The selection of the appropriate part number is based on the cable's core insulation diameter and conductor size. The following table provides a summary of the 158LR part numbers and their corresponding specifications:

For 24kV applications, the K158LR series is used, with part numbers adjusted to accommodate the higher voltage rating. The selection process requires careful consideration of the cable's specifications, including conductor type, insulation thickness, and screen type.

Safety Considerations

Safety is a critical aspect of high voltage elbow installation. Both the 600 Amp T-Body and Euromold 158LR elbows are designed for deadbreak applications, meaning they are not suitable for load-break operations. As such, they should only be installed in systems where the power is disconnected and the equipment is de-energized.

The installation of these connectors should be performed by qualified personnel who are trained in high voltage electrical work and are familiar with the manufacturer’s guidelines. Proper personal protective equipment (PPE) should be worn at all times, and all safety protocols should be followed to minimize the risk of electrical shock or injury.

In addition to following installation instructions, it is important to verify that all components are in good condition and that the connection is secure. Any signs of damage, wear, or improper installation should be addressed immediately to prevent system failures or safety hazards.

Conclusion

High voltage elbow connectors play a crucial role in electrical distribution systems by providing safe and reliable connections between medium to high voltage cables and electrical equipment. The 600 Amp T-Body and Euromold 158LR elbows are two types of connectors that are commonly used in power transformers, switchgear, and other high-voltage applications. Each connector has specific technical specifications, installation requirements, and compatibility considerations that must be followed to ensure proper performance and safety.

The installation process for these connectors requires a detailed understanding of the equipment and adherence to manufacturer guidelines. Proper preparation, cleaning, and torquing are essential to ensure a secure and durable connection. Additionally, the selection of the correct part number based on the cable's specifications is critical to achieving optimal performance.

For users and professionals working with high voltage electrical systems, understanding the differences between these connectors and their appropriate applications is essential. By following the correct installation procedures and safety guidelines, users can ensure the reliability and longevity of their electrical connections.

Sources

1. How to Install 600 Amp T-Body Elbow Terminations
2. Euromold 158LR Elbow Connector 11kV 24kV