Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.2 9/18/84; site harvard.ARPA
Path: utzoo!linus!philabs!cmcl2!harvard!katzman
From: katzman@harvard.ARPA (Cynthia Katzman)
Newsgroups: net.lan
Subject: Stand-by power supply for a Broadband cable plant
Message-ID: <373@harvard.ARPA>
Date: Thu, 26-Sep-85 12:23:10 EDT
Article-I.D.: harvard.373
Posted: Thu Sep 26 12:23:10 1985
Date-Received: Tue, 1-Oct-85 07:51:13 EDT
Distribution: net
Organization: Aiken Computation Laboratory, Harvard
Lines: 25

Ok... so I get the message-net.lan doesn't mind getting filled with
discussion on Broadband Cable issues.  Good.  

We are considering investing in either a UPS or a Stand-by power supply.  
My gut feeling is that we don't really need to spend the money on a UPS
for the cable plant, nor the head-end equipment.  (including a 68000 micro 
processor made by Momentum which is the Sytek Network Control Center.)  I 
really think that a Stand-by would do the trick.  (When we have power 
failures, the NCC is usually not affected.)

Anyway, while I have calculated the max. amps needed to protect everything,
I have not figured out how long I have before the cable plant goes out,
and users, both data and video, are affected.  (All my amps., both 
trunk and distribution, and presently powered by the Power Supply in the 
Head-end.)  

I'm seperating the back-up power for the cable plant, and that of the actual
Head-end equipment.  Does anyone out there have stand-by power?  Does anyone
have an automatic switch or some protection should the main PS fail?  My
feeling is that the cable plant could most likely support a 20 milisecond
AC out, (for stand-by power)  but I really don't have any facts to support
this.  

Cynthia Katzman
katzman@harvard.uucp 


Brought to you by Super Global Mega Corp .com