Mechanical Testing Of Connecting Leads Of Lightning Arresters On Transmission Lines

From an electrical point of view, the application of NGLA can often improve line performance with relatively few failures. However, utilities still report that NGLA installations are frequently affected by mechanical problems such as faulty connecting wires or disconnectors.

Although current arrester standards do not include requirements for mechanical testing or arrester connection, IEC 60099-5 recommends a minimum life expectancy of 25 years for arresters.

Mechanical testing of connecting wires
NGLA installations should be designed to minimize mechanical stress on the connecting conductors and disconnect switches, as these components (especially disconnect switches) cannot withstand high mechanical loads. Additional mechanical design considerations include:

1. The connection should allow free movement of the phase wire, which can take the form of conductor swing, wind vibration, galloping and sub-span vibration;
2. Connections and associated hardware shall withstand all mechanical forces to which they are subjected;
3. Connections should be durable to withstand movement-induced fatigue; installation and connections should not place excessive mechanical loads on surge arresters or disconnector accessories;
4. Disconnection of the surge arrester shall be carried out in a controlled manner without corresponding damage to the arrester or other equipment.