Ap one rugged wap - how to get grounding?

When connect to AP ONE using 6a shielded cable with grounded RJ45 (i.e. w drain wire) does the ethernet port on the AP support the ground? And, if so, how do I ground the metal case of the AP to a ground in my installation environment; do I need to scrape paint off the metal case around a mounting hole? I’m using the AC power option which has no ground on the plug. Thanks for any info…