CGC #1073

by CGC on June 24, 2011



                      THE CGC COMMUNICATOR

                            CGC #1073

                     Friday,  June 24, 2011


                Robert F. Gonsett, W6VR,  Editor

    Copyright 2011, Communications General® Corporation (CGC)



  Following is a synopsis of the latest Mt. Wilson power failure -- a 19 hour 
ordeal.  The failure began on June 21, 2011 when Southern California Edison 
(SCE) lost its one and only power feed to Wilson.  Most (if not all) 
broadcast stations switched to their backup generators.  All times are in PDT:

  JUNE 21, 2011

  5:50 PM -- Commercial (SCE) power to Mt. Wilson is lost.
  ABC was the first to note the loss via e-mail.  CBS Radio soon
  added: "All four CBS Radio sites are on generator power.  We
  have 0 volts on Edison, all three phases."

  10:23 PM -- Dennis Doty reports the SCE trouble crew "found
  the problem [on Mt. Wilson] it is up here on the north side
  where the overhead goes under ground."

  11:44 PM -- Cynthia Martin from SCE writes:  "The troublemen
  made it to Mt. Wilson.  They found that two potheads, associated
  with a pole that feeds into the Mt. Wilson substation, blew.
  Due to the complexity of the job to replace potheads, the
  decision was made to wait until tomorrow morning to make these
  repairs.  The cause was not found.  Hopefully, we will learn
  more tomorrow...."

  JUNE 22, 2011

  8:44 AM -- Bob Gonsett writes: "OSHA has good illustrations
  depicting potheads: .  More
  on potheads and "filling them with a protective and insulating
  compound: ...."  (Potheads
  come in various shapes and sizes and some are used to terminate
  individual conductors.  The word "pot" is probably derived
  from the term "potting compound.")

  9:21 AM -- Cynthia Martin of SCE writes: "I found out that
  we still do not know the cause of this outage.... Again, I
  apologize, on behalf of SCE, for the inconvenience you are

  12:06 PM -- One of the fuel tanks for emergency generators
  is running a bit low.  American Tower replies: "The fuel
  delivery is on its away and is expected to be there in about
  2 hours.  We have just under a 1/3 of tank."

  12:48 PM -- Dennis Doty writes, "SCE power has been restored
  to Mt Wilson.  12:43 PM Today."

  4:27 PM -- A network TV VP, while "not particularly happy
  with the timeliness of the repair," writes: "I give SCE a
  thumbs up for communication, especially compared to their
  counterparts elsewhere in the country."  Soon, a number
  of others add their praise for Cythina's efforts.

  5:18 PM -- A Mt. Wilson transmitter engineer writes:
  "I have taken care of transmitters at Mt. Wilson since late
  1977.  The current power outage frequency and durations are
  much worse than at any other time I can remember, other than
  perhaps the week of the Station Fire.  We used to go entire
  Winters where the only real use our generators got was for
  testing and maintenance...."

  11:00 PM -- Bob Gonsett writes to Cynthia Martin, asks
  if any potheads were actually replaced and adds, "Were any
  other repairs or improvements made?"  (So far, there has
  been no response other than a promise from Cynthia to

  Let's be patient.  Remember that on June 28, SCE is scheduled to 
reactivate their second power feed and transfer switch, so Wilson 
will once again have commercial power redundancy, and that should 
markedly reduce the number of outages.  Let's give thanks for the 
16 kV feed improvements in the vicinity of Mt. Harvard, the successful 
reconstruction of the backup power line following the Station Fire and 
the fact that Cynthia Martin keeps the lines of communications open.

  Although Murphy lives and we may run into a few more glitches yet, 
things should become a whole lot better soon.



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