In years past we had a bank of 75 Oneac 66 block protectors that was grounded to the grounding stud on an Oneac surge suppressor - the stud that was meant to ground the suppressor. My analog extensions extend up a mountain to 6800 feet in elevation and 15000 feet away from the pbx. We blew two Toshiba PBXs in one year, and over a couple years $1000 worth of protectors each year. That's what can happen with improper installation
. It's all done right now and to code.
