Mysterious Earth Cable
Mysterious Earth Cable
(OP)
Hi all,
I found a earth cable linking the excitation transformer (230kV/660V) LV terminal box to the generator excitation panel (earth bar). The power cables from the transformer to the panel is single core without screen/shealth.
I was wondering what is the purposes for this earth cable?? If it is for earthing the transformer's terminal box, why can we just link it to the transformer body and earth at site? Instead, a cable was laid all the way from the panel to the transformer (abt 100 meters).
I found out this earth cable because "hot spot" was detected using thermography at the earthing cable termination at the transformer terminal box.
Thanks in advance!
I found a earth cable linking the excitation transformer (230kV/660V) LV terminal box to the generator excitation panel (earth bar). The power cables from the transformer to the panel is single core without screen/shealth.
I was wondering what is the purposes for this earth cable?? If it is for earthing the transformer's terminal box, why can we just link it to the transformer body and earth at site? Instead, a cable was laid all the way from the panel to the transformer (abt 100 meters).
I found out this earth cable because "hot spot" was detected using thermography at the earthing cable termination at the transformer terminal box.
Thanks in advance!






RE: Mysterious Earth Cable
RE: Mysterious Earth Cable
I might not have explained my situation properly.
The excitation panel is already earthed through a earth bar in this panel. On the other hand, the transformer terminal box is not earthed locally but has this earth cable running all the way to be connected to the excitation panel earth bar.
Also, can you elaborate "to reduce the return impedence in case of a ground fault". Thank you!
RE: Mysterious Earth Cable
RE: Mysterious Earth Cable
The grounding is done at the panel in this case. However, our whole station makes use of a common earth grid, so I presume that earthing done anywhere is the same.
I got a comment from a colleague that the earth cable might have been pulled along with the power cable, so since it is there, just earth it at a convenient point.
What do you think?
RE: Mysterious Earth Cable
RE: Mysterious Earth Cable
RE: Mysterious Earth Cable