[ale] Not so evil empire

[David Ritchie]

On Thu, Jul 16, 2009 at 2:08 AM, Robert Reese<ale at sixit.com> wrote:
> Oh, by the way.... here's a good trick to know if the power is likely to be out for a while - 3 Strikes You're Out!  Transformers (for overhead lines) and those green power boxes in your neighborhoods with underground power both have 3-step fuses.  When first tripped they go out for 10-30 seconds (I can't recall the specific times for any stage, sorry) and then 'reset' to the second step.  If it immediately trips the second time, it also goes out for a short period (I believe this one is 30 seconds) and resets to the third step.  Tripping the third step is permanent and almost universally means the power line is grounding somewhere (in the case  of overhead lines, literally grounding on the ground) and you are on the still-standing side.  Pretty much the same for the green boxes.
>
> Hence, the Three-Strikes rule: if it goes out, comes back, immediately goes out, and comes back, know that if it goes back out the third time it is likely to be awhile before it comes back on.  The good news is that it is possible for the crews to disconnect somewhere closer to the fault and get your power back on before the lines are repaired, or better yet they tripped from a lightning strike somewhere and just need the fuse replaced.

These are actually called 'reclosers'. They have to be reset after the
3rd cycle, but it is not a replacement issue, but does require a
lineman with a hotstick to reset them.
However, if it trips out it means either
   1) monster winds are slapping together adjacent phases of the high
lines together or
   2) something fell across the phase  or
   3) or a line fell to ground or
   4) lightning hit some switch gear or
   5) an underground cable shorted out a phase or ...

Unfortuantely, this requires some one to go out and drive around, or
at least look at a section map to see if they can correlate 'lights
out' reports to a particular phase
being out, etc...All of these things will happen before the recloser
is reset, most likely.

I recommend that if you have a 'lights out' situation, you call the
automated trouble reporting line immediately from your home phone.
This must be a regular phone (unless you have your cordless phone on a
UPS), as it does the account/address lookup at Georgia Power via ANI
information (i.e. your phone #) as passed from the phone company.

If you are in a location where the bill does not go to your address,
you need the account # to report power out. No account #, no report
(at least I have never seen a way to do it).
This is most commonly a problem with businesses (for example, my
wife's H&R Block office had this problem due to not knowing the
account code).

> Also, if you look out and SOME of your neighbors have power, or even MOST of them have power, it is likely a phase problem.  Most residential homes are single-phase only.  Three-phase is almost exclusively for business, though a wise consumer building their home should pay the premium for three-phase cabling to their new home.  Trust me, this is well worth the price if you can arrange for it before the service line is laid or hung.
>
> The relevant advantage to this topic is frequently one leg of the three phases is looped through the neighborhood, or (IIRC) less frequently all three legs are looped through the neighborhood and in rotating series split off to each of the homes on the loop.  Look at your power poles or your green boxes to see if you have A, B, or C, *or* A and B and C.

3 phase into a home? never heard of that happening. I am not event
certain you can do that under NEC. The biggest reason you need 3 phase
power is for large industrial motors or extremely large current
requirements. (3 phase motors inherently always  have two legs that
have energy moving through them, unlike a single phase where voltage
crosses through 0 volts 120 times a second).
You would need to show commerical use. But I could be wrong... just
based on my experience in the SCADA group at Knoxville Utilities Board
many many years ago....

Best regards,
Dave Ritchie