For Bolt-type Clamps Used In Parallel Groove Installation, The Bolts Must Be Tightened Evenly During Installation.
During the installation of a parallel groove clamp, achieving uniform pressure across all bolts ensures optimal electrical conductivity and mechanical stability. Uneven torque can lead to localized overheating, increased resistance, and eventual joint failure under thermal cycling conditions.
Effective Torque Management for PG Connectors
When securing a parallel groove connector, the sequence of tightening is as critical as the final torque value. Technicians must apply pressure in a graduated, alternating pattern. This method prevents the clamp from tilting or distorting, which could reduce the contact surface area between the conductor and the clamp grooves.
How to install a parallel groove clamp correctly?
To ensure a high-quality connection, place the conductors into the grooves and hand-tighten the bolts. Use a calibrated torque wrench to tighten each bolt incrementally in a "criss-cross" or alternating sequence. This process distributes pressure evenly, minimizing contact resistance and preventing mechanical deformation of the aluminium pg clamp or bimetal pg clamp.
Step-by-Step Installation Procedure
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Preparation: Clean the conductors with a wire brush to remove oxide layers and apply a high-quality joint compound.
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Positioning: Insert the main and tap conductors into the respective grooves of the parallel groove clamp.
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Initial Seating: Tighten all bolts by hand until the clamp plates make firm contact with the wires.
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Incremental Tightening: Rotate each bolt by one-half turn at a time, moving between bolts to maintain a level alignment.
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Final Calibration: Apply the manufacturer-specified torque (typically measured in Newton-meters) to every bolt.
Common PG Clamp Specifications
The following table outlines standard torque requirements and material applications for various connector types:
| Clamp Material | Conductor Range (mm²) | Recommended Torque (Nm) | Application Environment |
|---|---|---|---|
| Aluminium Alloy | 16 - 95 | 20 - 25 | Standard AAC/AAAC lines |
| Aluminium Alloy | 120 - 240 | 40 - 45 | Heavy-duty transmission |
| Bimetal (Al-Cu) | 25 - 150 | 35 - 40 | Dissimilar metal joints |
Maintenance and Long-term Reliability
Environmental factors such as wind vibration and temperature fluctuations can affect the integrity of a parallel groove connector over time. Utilizing a bimetal pg clamp is necessary when joining copper and aluminum to prevent galvanic corrosion.
Periodic inspections should include checking for signs of discoloration or "burning" around the aluminium pg clamp. Re-checking torque levels after the first 24 hours of installation can account for initial material "creep" and ensure the connection remains secure throughout its service life.
