Edward_Greenberg@cso.3mail.3com.com (04/14/90)
John Higdon writes: >Except for some lineman's sets, there are no "ground-start phones". >Ground-start trunks are for PBXs and other complex equipment, not >for ordinary telephone sets. It's true that (almost) nobody would order a ground start line for a POTS (plain old telephone service) line, but here's a situation where a 2500 set (standard touch tone desk set) was equipped with a grounding button: In most PBX installations, when both power and backup power fails, certain stations are direct-connected to certain trunks. This allows, for example, the main number to ring at security, and one phone in each functional area to receive dial tone, for the duration of the power outage. This feature is called power fail transfer. In one installation, the sets designated for power fail transfer were equipped with grounding buttons, since the lines that they'd be receiving in case of outage were ground start lines. Those who "needed to know" were briefed that in case of switch outage, they needed to press the button to receive a dial tone. edg@cso.3mail.3com.com