Elastimold® load break elbows and associated components are critical accessories for high-voltage underground power distribution systems. Designed for 15 kV and 25 kV class applications, these connectors and elbow joints provide a secure and reliable means of connecting, disconnecting, and testing power distribution cables. The system supports continuous current ratings of 200A and 600A configurations, making it suitable for a wide range of utility and industrial environments.
This article provides an overview of the technical specifications, installation considerations, and operational features of Elastimold load break elbows based on the manufacturer documentation and component data provided. The focus is on the 200-amp load break and deadbreak elbow systems, which are commonly used in power distribution networks for energized operations, fault isolation, and system testing.
Technical Overview of Elastimold Load Break Elbows
Elastimold load break elbows are modular, separable connectors that allow energized loadmake and loadbreak operations using standard hotstick tools. These devices are suitable for both 15 kV and 25 kV class systems and are designed for use in ambient temperatures ranging from -40°C to +65°C in underground applications such as direct burial and submersion.
Key Features and Ratings
According to the provided documentation:
Current Ratings:
- 200A continuous
- 10 kA symmetrical 10 cycles (short circuit protection)
Voltage Ratings:
15 kV class:
- 8.3 kV phase-to-ground
- 14.4 kV phase-to-phase
- 95 kV BIL (Basic Impulse Level)
- 34 kV AC Withstand
- 53 kV DC Withstand
- 11 kV Corona Extinction
25 kV class:
- 15.2 kV phase-to-ground
- 26.3 kV phase-to-phase
- 125 kV BIL
- 40 kV AC Withstand
- 78 kV DC Withstand
- 19 kV Corona Extinction
35 kV class:
- 21.1 kV phase-to-ground
- 36.6 kV phase-to-phase
- 150 kV BIL
- 50 kV AC Withstand
- 103 kV DC Withstand
- 26 kV Corona Extinction
Test Point Availability:
All 200-amp load break elbows come equipped with a standard test point, allowing for direct conductor voltage testing using a 200TC-X series meter adapter, a properly rated voltage meter, and a hot-line stick.Design and Construction:
- Deadbreak and loadbreak connectors are modular and feature bolted connections for large conductor applications.
- The deadbreak connectors require de-energization for operation and must be mechanically secured with bails when connected.
- Loadbreak connectors allow energized operation and visible disconnection.
- The connectors support multiple junction points and taps via junctions or feed-thrus.
Installation Considerations and Accessories
Installation of Elastimold load break elbows involves careful selection of components based on cable size, insulation type, and conductor configuration. The documentation specifies that all components must be isolated using insulated caps, plugs, and parking bushings when not in use or during maintenance. The following are critical accessories and considerations:
Cable Size and Insulation Compatibility
The documentation emphasizes that cable size and insulation diameter must be verified using the W and X tables provided in the manufacturer’s catalog. These tables detail the appropriate elbow and connector part numbers for specific cable sizes and insulation types. For example:
Cable Size Adapter (160CA-W):
This adapter is used to match the elbow to different cable sizes and is compatible only with specific elbow part numbers such as 165LR and 166LR in C size.Insulating Plug (10EP-W):
Used to seal the cable entrance and prevent contamination or moisture ingress. It is compatible with 15/25 kV systems and should be selected in conjunction with Table W6 for proper sizing.Test Point Cap (156-7):
A standard accessory for loadbreak elbows, enabling direct voltage testing without de-energizing the system.
Grounding and Isolation
Grounding is a critical aspect of installation safety and system maintenance. The documentation outlines several grounding-related components:
Grounding Plug (151GP):
Used to ground the elbow when it is not in service. It is compatible with 15/25 kV systems and must be installed in accordance with local safety codes.Insulated Parking Bushing (K151SOP):
Provides a safe, insulated method of temporarily isolating an elbow connector during maintenance or testing.Feed-Thru Insert (K1501FT):
Allows for the continuation of the circuit without breaking the connection while enabling testing or grounding operations.Bushing Insert (K1501A1):
A standard insert used in conjunction with bushing wells for secure and insulated connections.
Mechanical and Structural Components
Several mechanical components are integral to the installation and operation of Elastimold load break elbows:
Bail Assembly (150BA):
Used to secure deadbreak elbows mechanically when connected. Bails are essential for maintaining the integrity of the connection and preventing accidental disengagement.Compression Lugs and Adapters:
These components ensure a secure mechanical and electrical connection between the elbow and the cable. The documentation specifies that compression lugs must be installed in accordance with the manufacturer’s torque requirements and that the cable must be prepped and stripped to the correct dimensions.Locking Splice/Repair Splice (K151LS-W0X):
Used for repairing damaged cables or splicing two cables together. This component must be selected based on cable size and insulation type and must be installed using the appropriate tools and procedures.Straight Receptacle (K151SR-W0X):
A modular component that allows for the connection of multiple cables or devices. It is compatible with 15/25 kV systems and is typically used in conjunction with other junctions or connectors.Tee Splice (K150T):
Used to create a three-way connection between cables. It is a standard component for creating branch circuits or adding new taps to an existing system.
Operating Accessories
The documentation also describes several operating accessories that facilitate installation, testing, and maintenance:
Spanner Wrench:
A standard tool used for tightening or loosening compression lugs and other threaded components.Assembly Tool:
A specialized tool used for installing and securing elbow connectors, particularly in tight or confined spaces.Hotstick Tools:
Used for energized loadmake and loadbreak operations. These tools are essential for working on live systems without the need for full de-energization.Voltage Detection Cap (156LRF):
A test cap that allows for the detection of voltage on an elbow without direct contact. This is used for safety verification before de-energizing the system.Reducing Tap Plug:
Used to connect smaller cable sizes to larger conductors or devices. This component must be selected based on the cable size and insulation type.
Safety and Compliance Considerations
The Elastimold load break elbow system is designed to meet the requirements of various industry standards and codes. The documentation does not specify which standards apply, but the inclusion of BIL, AC and DC withstand ratings, and corona extinction levels suggests that the system is likely compliant with IEEE, ANSI, and IEC standards for high-voltage equipment.
Safety is a critical consideration during installation and operation. The documentation emphasizes the following:
- All deadbreak connectors must be de-energized before installation or removal.
- Loadbreak connectors may be operated while energized using hotstick tools, but operators must follow strict safety procedures.
- Components must be properly isolated using insulated caps, plugs, and parking bushings to prevent accidental contact with live conductors.
- All installation and maintenance work must be performed in accordance with local safety codes and the manufacturer’s guidelines.
Maintenance and Troubleshooting
Maintenance of Elastimold load break elbows involves regular inspection of components for signs of wear, damage, or contamination. The documentation does not provide specific maintenance schedules but suggests the following:
- Inspect all connectors, elbows, and junctions for signs of corrosion, overheating, or mechanical stress.
- Check all compression lugs and connections for proper torque and integrity.
- Verify that all insulating caps, plugs, and bushings are in place and undamaged.
- Perform regular voltage testing using the test point and appropriate metering equipment.
- Replace any damaged or worn components immediately.
Troubleshooting is typically required when a system experiences performance issues, such as:
- Intermittent or complete loss of power.
- High resistance readings during voltage testing.
- Visible damage to connectors or insulation.
- Mechanical failure of bails, compression lugs, or junctions.
In such cases, the system should be de-energized, and components should be inspected for damage or wear. If a component is found to be faulty, it should be replaced with a manufacturer-approved replacement part.
Conclusion
Elastimold load break elbows are essential components in high-voltage underground power distribution systems. Designed for both 15 kV and 25 kV class applications, these connectors provide a reliable and modular solution for connecting, disconnecting, and testing power distribution cables. The system supports continuous current ratings of 200A and 600A and is equipped with test points, grounding capabilities, and a range of junction and connection options.
Installation of these components requires careful selection of parts based on cable size, insulation type, and conductor configuration. Accessories such as insulating plugs, grounding plugs, and insulated caps play a critical role in ensuring safety and reliability during installation and operation. Operators must follow strict safety procedures, including de-energizing deadbreak connectors and using hotstick tools for loadbreak operations.
For users and technicians involved in power distribution and electrical infrastructure, understanding the technical specifications, installation requirements, and operational features of Elastimold load break elbows is essential for ensuring system performance and safety.