Hvar eru kopar- og álbúnaðarklemmur almennt notaðar?
There are two most common situations for selecting power equipment clamps in power design. :
1. Val á álagsklemma þegar LGJ og LJ leiðarar eru notaðir
Þegar LGJ eða LJ vír er notaður, þar sem álagsklemman er klemmd á ytra þvermál vírsins þegar hún er notuð, ætti að velja líkanið af álagsklemmunni sem notuð er í samræmi við ytra þvermál vírsins. Til dæmis er LGJ-185/30 vírinn notaður í raflínuna. Eftir útreikning má finna að ytra þvermál þess er 18,88 mm. Af ofangreindri töflu er vitað að álagsklemma ætti að vera NLL-4, NLL-5 eða NLD-4.
It should be noted here that the outer diameter of the LGJ wire is calculated from the cross-section of the aluminum wire 185mm and the cross-section of the steel core 30mm. It is not simply calculated by the cross-section of the aluminum wire 185mm. LGJ wires of the same specification have different steel core cross-sections and wire outer diameters, so the strain clamps used for LGJ wires of the same specification are not necessarily the same. If it is an LJ wire, since it does not have a steel core, the cross-section of the aluminum stranded wire can be used to calculate the outer diameter of the wire.
Þar að auki, vegna þess að spennuklemman er þvinguð á ytra þvermál vírsins, er nauðsynlegt að vefja ytra lag LGJ eða LJ vírsins með álbandi meðan á smíði stendur til að koma í veg fyrir að vírinn skemmist við kreppu.
2. Val á álagsklemma þegar einangraður vír er notaður
In densely populated, wooded, and polluted areas, more and more insulated wires are used instead of bare wires. Compared with bare wires, it has the advantages of higher safety and reliability, lower wire loss, and less wire corrosion. When using insulated wires, it should be noted that the strain clamp is clamped on the outer diameter of the "wire" instead of the outer diameter of the "conductor" when used, so it should be based on the outer diameter of the wire instead of the conductor To select the type of strain clamp used. For example, JKLGYJ-150/8 steel core reinforced cross-linked polyethylene insulated aerial cable is used in the power line. It is calculated that its conductor outer diameter is 15.30mm, plus its insulation thickness of 3.4mm and conductor shielding thickness 0.5mm, it can be seen that the outer diameter of its conductor is 23.1 mm. Check the above table to know that the strain clamp that should be used is NLL-5. If the equipment clamp is selected according to the conductor outer diameter 15.30mm at this time, the selected equipment clamp cannot be used.
In addition, tighten the screws evenly when installing the strain clamp. It is required that there is no increase in the wire stress at the contact surface between the wire and the metal after installation, so as to prevent damage to the wire due to breeze vibration or other wire oscillations and ensure that The grip strength of the strain clamp on the wire is not less than 95 percent of the wire breaking force.
