ATC/Diversified Voltage Alerts This topic contains 1 reply, has 2 voices, and was last updated by John C 8 months, 2 weeks ago. Author Posts May 3, 2017 at 9:51 am #9671 Sonny BeckettParticipant I need info on these saftey devices please May 3, 2017 at 9:58 am #9672 John CGalco Representative These devices connect to your incoming power lines after the disconnect in your panel. They measure voltage from phase to phase and phase to ground and provide indication with LEDs only. They mount in a 1 1/4″ or a 30mm knock-out hole. Author Posts You must be logged in to reply to this topic.