The classic reduced phase clamp for round-section conductors (Cr) has a profile which facilitate its hanging on conductor horizontally positioned or slightly inclined towards the ground. The reduced classic clamp is a clamp with screw fastening, where the conductor is firmly fastened between the clamp’s body and the mobile jaw driven by screw.
The tightening force is provided by the clamping torque of the clamp’s driving screw. Both the clamp body and the mobile jaw are aluminium alloy die cast items. The driving screw has a ‘’RO bayonet’’ end which allows easy coupling and detachment of the clamp from the ‘’RO bayonet’’ coupling systems of insulating sticks.
In order to reduce the operator’s effort, the tightening of the driving screw is relieved by the presence of a compression spring which allow an easy movement of the mobile jaw.
The clamp is detached from the conductor by the simple opening of the clamp (by unscrewing the driving screw, the mobile jaw is lowered), followed by the lifting of the clamp from the conductor.
The automatic phase clamp for round conductors is also a screw-operated fastening clamp, the conductor being tightened between the clamp’s body and its mobile jaw. Additionally, this type of clamp is provided with a system of levers and springs that allows the automatic closing of the clamp’s jaw upon the contact of levers with the conductor (pre-fastening of the clamp on the conductor). Subsequently to this phase, which provides much easier handling the clamp, the fixing of the clamp must be completed through the tightening of the driving screw to the proper torque specification. Similar to the classic clamp, the automatic clamp includes two aluminium alloy cast items and a driving screw provided with a ‘’RO bayonet’’ end.
The dismounting of the clamp from the conductor is similar to the one used by the classic clamp, more exactly the screw is unscrewed, the jaw is lowered until there is sufficient space to lift the clamp from the round conductor.
|Technical characteristics||Classic reduced clamp (Cr)||Automatic clamp (CA)|
|Nominal short-circuit for t = 1 s Isc (kA)||30||30|
|Clamp body execution procedure||Extruded body||Cast body|
|Material||Aluminium alloy||Aluminium alloy|
|Thickness of conductor bar where the phase clamp can be applied (mm)||–||–|
|Diameter of the sphere (mm)||28||28|
|Diameter of the conductor where the phase clamp can be applied (mm)||17 ÷ 32||17÷32|
There are two types of Phase clamps for round-section conductors: multi-core flexible conductors, rigid bars, T-type fixed couplings or other parts assembled permanently on conductors in power substations: