PTP820C installation advice?


I’m in the process of deploying some 820c radios, and I wanted to ask for some advice from anyone who has experience installing them.

We planned power these radios using 18AWG, 4-wire shielded cable, for all our installations between 35-50m up the towers. According to documentation, Surge-protection on DC(and ethernet) interfaces is built-in to the radio, which is great, but also concerning.
I’m unsure if I should use a shielded wire? If I do, do I take any considerations for the drain wire? Should I have the drain wire attached to the ground lug on the radio chassis?

Ordinarily in an installation of this nature, I would run the DC cable from top to bottom, and place a Transtector DC Surge Protector beside the radio on the tower, where I can ground the drain, and a second at the bottom inside the main cabinet. Since the 820c has it’s on SS built in, am I safe to use only 1 transtector per radio(at the bottom) instead of two?

Anyway, I’m curious what Cambium(or anyone for that matter) would recommend for best for the installation I’m describing. Any advice would be appreciated.