What Is The Main Basis For Selecting Tension Clamps

The selection of Circuit breaker is mainly determined by the different conditions of the power line conductor. There are two common situations.

1. Selection of line tension clamps when using LGJ and LJ conductors

When using LGJ or LJ conductors, since the tension clamps are clamped on the outer diameter of the conductor when used, the model of the tension clamp used should be selected according to the outer diameter of the conductor. For example, the LGJ-185/30 conductor is used in the power line. After calculation, it can be known that its outer diameter is 18.88mm. From the above table, it can be known that the tension clamps that should be used are NLL-4, NLL-5 or NLD-4.

It should be noted here that the outer diameter of the LGJ conductor is calculated by adding the aluminum wire cross section of 185mm and the steel core cross section of 30mm, and it is not simply calculated by the aluminum wire cross section of 185mm. LGJ conductors of the same specification have different steel core cross sections and conductor outer diameters, so the tension clamps used for LGJ conductors of the same specification are not necessarily the same. If it is an LJ conductor, since it has no steel core, the cross section of the aluminum stranded wire can be used to calculate the outer diameter of the conductor.

In addition, since the tension clamp is clamped on the outer diameter of the conductor, we require the outer layer of the LGJ or LJ conductor to be wrapped with aluminum tape during construction to prevent damage to the conductor during crimping.

2. Selection of line tension clamps when using insulated conductors

Compared with bare conductors, insulated conductors have the advantages of high safety and reliability, reduced line loss, and less corrosion of conductors. When using insulated conductors, we need to pay attention to the fact that the tension clamp is clamped on the outer diameter of the "conductor" instead of the outer diameter of the "conductor" when used, so the model of the tension clamp used should be selected according to the outer diameter of the conductor instead of the outer diameter of the conductor.

In addition, when installing the tension clamp, we must tighten the screws evenly, and require that there is no increase in the stress of the conductor at the contact surface between the installed conductor and the metal original, so as to prevent the conductor from being damaged by breeze vibration or other conductor oscillation and ensure that the grip of the tension clamp on the conductor is not less than 95% of the conductor breaking force.