What are the conditions that the 3 line to ground arresters are not sufficient?
My case is the following, I have 30kV/0,69kV transformers (Delta primary) on which the manufacturer only installed phase to phase arresters. The local authority (TUV) questions this practice.
All our power...
Busbar,
Thanks for the interesting paper proposed, I did not have the time to read it yet as I have to go and work on the VFD problem today. As for the Cahiers Techniques I already consulted them and they are quite interesting and practical.
From what I could see from Merlin Gerin "Cahiers...
Hi,
I am now comissioning a plant in Germany and the low voltage system in use is the new European 690V voltage.
The system here is defined as "IT system" meaning that the neutral is not grounded.
The system has the required Insulation monitors that will alarm on the occurence of first ground...