Critical review of the dielectric testing of some live line tools

Dielectric tests performed on live line tools are essential to ensure the safety of the work. This paper shows some possible improvements to the standards defining measurements of insulating sticks and insulated boom aerial devices. Laboratory experiments and simulations were carried out on insulating sticks in order to evaluate various electrode arrangements applied in practice during voltage probe. In case of insulated boom aerial devices, calculations were performed to clarify the consistency of insulation resistance limits with other measurements and the dimensions of the insulating insert. The value added to the test by observing the temperature of the insulating insert during leakage current measurement has been assessed by a rough estimation of the temperature rise. The leakage current measurement with focus on the role of the stray capacitances has been evaluated based on the experience of the High Voltage Laboratory and theoretical considerations.