I am in the design stage of a surge supressor unit to be placed inline with a unit that has a remotely located radio and antenna. My major concern is protecting the indoor equipment from surges caused by lighting in the near vacinity. The data and power supply voltages that go through the box and need protection are +5 VDC, +/_ 12VDC and +12 VDC constant. The external box is a Fibox weathertight plastic type. The question is where do I find the grouding requirements that would be applicable to this type of equipment and installation.