Path: utzoo!attcan!uunet!mailrus!accuvax.nwu.edu!nucsrl!telecom-request From: starr@hriso.att.com (Michael L. Starr) Newsgroups: comp.dcom.telecom Subject: High Voltage (was: Pseudo PBX For the Home?) Message-ID: <10137@accuvax.nwu.edu> Date: 25 Jul 90 16:38:37 GMT Sender: news@accuvax.nwu.edu Reply-To: "Michael L. Starr" Organization: AT&T HRISO, Morristown, NJ Lines: 32 Approved: Telecom@eecs.nwu.edu X-Submissions-To: telecom@eecs.nwu.edu X-Administrivia-To: telecom-request@eecs.nwu.edu X-Telecom-Digest: Volume 10, Issue 517, Message 3 of 9 In article <10036@accuvax.nwu.edu> julian@bongo.uucp (Julian Macassey) writes: X-Telecom-Digest: Volume 10, Issue 508, Message 1 of 5 >The Ringer >The voltage at the subscribers end depends upon >loop length and number of ringers attached to the line; it could be >between 40 and 150 Volts. Note that ringing voltage can be hazardous; >when you're working on a phone line, be sure at least one telephone on >the line is off the hook (in use); if any are not, take high voltage >precautions. The telephone company may or may not remove the 48 VDC >during ringing; as far as you're concerned, this is not important. >Don't take chances. This reminds me of an incident many years ago that happened to me. I was setting up equipment in a hotel conference room for a demo when I hit on the problem of connecting the modems to the phone line. The hotel phone was hardwired, and of course we needed a modular connection. The simple solution seemed to be to tap a modular junction box into the hardwired junction box. Although I had experienced the thrill of being shocked by military field phone magnetos, it never occurred to me to take the receiver off the hook (after all, I was only dealing with 48 VDC). As you might have guessed, a call came in during my wiring, and gave me quite a jolt! It only takes one time to learn your lesson. __/\__ ******************** __/\__ | starr@hriso.ATT.COM \ / * Michael L. Starr * \ / | att!hriso!starr |/\| ******************** |/\| | attmail!starr