n5sx...@charter.net wrote:
>
>
> I must admit that I don't see the problem with the sensitive equipment
> not finding ground thru the floor! In the 1980 I have some telephone
> central offices built by TRW. Each of the equipment racks were mounted
> on thick plastic sheets, and the mounting bolts were inserted thru
> insulating shoulder washers. Each equipment rack had a "dedicate home
> run" ground back to the main central office ground buss plate. All
> worked well, with no lightning problems. Some many years later I was
> still working for the same telephone company when I was asked to go back
> to that office to see why the new equipment addition would not work. It
> was needed badly as the C.O. was out of lines and needed this expansion
> to work. A quick inspection showed that the new equipment had been
> mounted directly to the concrete floor with out the insulation kit. I
> had the CO crew there help jack the rack up and slide a rubber floor mat
> under it for temporary insulation. We verified that the ground strap was
> correctly installed, and when we returned that equipment cabinet to
> service , it came up and worked fine. The equipment installer was forced
> to return at night to correct his problems. So not everything should be
> chassis grounded to the floor.
> Jeff
>
