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Thread: Component lifetime

  1. #11
    Join Date
    Apr 2008
    Location
    Ann Arbor, Michigan
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    6,335
    171115-0930 EST

    Lots of interesting information.

    Just went out and looked at my poles, 3 of 5, all three were MBT Co with no date. There are newer tags with 2000 and 2010 markings. MBT stands for Michigan Bell Telephone Co. which became Ameritech, and now AT&T. The MBT poles date from at least 1960, and possibly 1950.

    Where I grew up the poles were planted about early to mid 1920s, and I do not believe many have been replaced.

    K9MHZ, how is your daughter able to date a pole? Are there date codes on older poles owned by Consumers as distinguished from MBT?

    Ingenieur: your long reference was quite interesting. So there are a lot of possible ways for failure to be a direct result of a mechanical failure. I have been wondering if one can consider a dielectric breakdown in some cases to be a mechanical failure rather than electrical.

    On my block possibly 2 transformers have failed in the almost 60 years of the installation. There about 30 homes on the block. My 25 kVA transformer was one and it was an oil leak. This transformer was not overloaded, 2 homes with gas for heavy power loads. My average load is 1 to 2 kW. Now have a 50 kVA transformer. Within a reasonable distance of my home I don't believe there is anyone with solar power, and possibly no EV cars requiring chargers. Quite a few Hybrids. There are at least two different 3 phase installations. The 50 kVA transformer is possibly an assumption that there will be EV cars, and/or solar in the future.

    What sort of started this thread was that on Friday I am going to take an ESD (Engineering Society of Detroit) tour of the very high voltage lab at Kettering University in Flint. Kettering was originally GMI (General Motors Institute) and is located near the University of Michigan Flint campus.

    Back when I was very young and until my late 20s our power cost was 2.5 cents per kWH. It is now about 16 per kWH. By some estimates the value of the dollar over this time has depreciated by a factor of 30. Even if you used 10, and it is definitely worse than 10, our present cost is less than when I was young. This lower real cost was mostly a result increased efficiency of power generation.

    To try to keep the cost of electricity low and ignore the infrastructure is a major mistake. Everyone needs their own generator. Where are very large transformers made? How long to make one? How many backups are available?

    Looking for information on the Ford Highland Park power plant I did not find what I wanted, but came across this interesting link:
    https://en.wikipedia.org/wiki/List_o...ns_in_Michigan

    .

  2. #12
    Join Date
    Mar 2008
    Location
    Michigan. It's a beautiful penninsula, I've looked around.
    Posts
    9,428
    This, from my daughter:

    There will usually but not always be a brand on the pole. The 595 at the top means this pole was placed may 1995. The 6 40 at the bottom means it was a class 6 (the size it is around) and 40 feet high


    The 1936 poles have a little tag on the pole that says that stuff rather than a brand. If I see another one of those I’ll send a picture.

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    Cheers and Stay Safe,

    Marky the Sparky

  3. #13
    Join Date
    Apr 2008
    Location
    Ann Arbor, Michigan
    Posts
    6,335
    171115-1224 EST

    K8MHZ:

    Looked at 2 of my poles and within a convenient visible range I did not find any branding. It is raining outside so I did not get out spyglasses to look higher up the pole.

    .

  4. #14
    Join Date
    Mar 2008
    Location
    Michigan. It's a beautiful penninsula, I've looked around.
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    9,428
    Quote Originally Posted by gar View Post
    171115-1224 EST

    K8MHZ:

    Looked at 2 of my poles and within a convenient visible range I did not find any branding. It is raining outside so I did not get out spyglasses to look higher up the pole.

    .
    She is just doing poles for Consumers. If DTE does mark their poles, they may use a different method. Also look for metal label plates, I have a pole with such a plate on my corner.
    Cheers and Stay Safe,

    Marky the Sparky

  5. #15
    Join Date
    Mar 2008
    Location
    Michigan. It's a beautiful penninsula, I've looked around.
    Posts
    9,428
    I just found this on a search:

    Branding --- In the United States, utility poles are marked with information concerning the manufacturer, pole height, ANSI strength class, wood species, original preservative, and year manufactured in accordance with ANSI standard. This is called branding, as it is usually burned into the surface; the resulting mark is sometimes called the "birth mark".
    Cheers and Stay Safe,

    Marky the Sparky

  6. #16
    Join Date
    Apr 2008
    Location
    Ann Arbor, Michigan
    Posts
    6,335
    171115-1440 EST

    K8MHZ:

    I will look for a DTE pole as distinguished from an MBT pole and see if there is branding.

    I took off on a tangent to see about DTE power distribution, and came across the following very interesting discussion:
    Page 1 is probably not as interesting as page 2.
    https://www.detroityes.com/mb/showth...ion-of-Detroit
    https://www.detroityes.com/mb/showth...-Detroit/page2
    A very long read, but many interesting points about interconnecting plants, and voltages.

    My uncle joined DTE in the mid 1920s after graduating from the U of M. To the best of my knowledge he was in overhead lines until about 1950 when he became chief field engineer for unground lines, he liked non-office work. I looked to see if there was mention of a line he worked on around the early 1950s. This was a high voltage underground line around the western side between power plants on the north, and south sides of Detroit. There was an overhead line discussed, but no mention of this underground line. I don't remember the voltage, but from reading the discussion my guess is 120 kV. They may have used pressurized nitrogen to reduce the insulation problem at high voltage underground.

    .

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