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Thread: Power interruptions

  1. #1
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    Power interruptions

    Monday evening the power went off and on at least 8 times in 10 minutes as the breaker at the substation kept trying to reset. Unusual as they usually only try three times before shutting off the power. Anyway I was worrying about all of my electronics as I was watching the game on my new TV with the cable box attached and the surround system fired up. No problems what-so-ever. I guess my whole house panel surge protector and my premium power strips did their job. Had the panel protector in probably 12 years and both LED's still light up. I understand if you take a hard hit, they are designed to fail. So far, so good. It is an inexpensive (under $50) Intermatic I picked up at HD.

    At church, we needed $7000 in repairs to our elevator controls after a surge this summer and we lost a $5000 duplicatior last winter, so we are installing 3 phase surge protection for the elevator and premium strips for the office and other electronics.
    NOW you tell me...

  2. #2
    Power goes off like a third world country round here. And we had everything flashing last night. In our community it is usually drunks hitting poles. Our area is dry so they have to travel to other places to drink in a bar.

  3. #3
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    I have most of our sensitive electronics on small UPS systems which eliminate the bounce between when the provider power goes out and the generator cuts in. They only need to power things for a very short period of time, so "big and clunky" isn't required.
    --

    The most expensive tool is the one you buy "cheaply" and often...

  4. #4
    Here, power companies merged several years back. When we were CP&L (Progress) customers, you didn't need a generator, but now that Duke has our service, you had better have a generator, or not have any foods that are (were) frozen. Typical outages went from less than four hours to over 15 hours. I'm not talking about ice storms, or hurricanes either. Just plain SORRY customer no service.

  5. #5
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    One of the serious national infrastructure changes that has to be brought forward is eschewing arial transmission in favor of underground routing, particularly in areas prone to failure due to wind and weather damage. Expensive, yes. But considering the great cumulative cost of restoring power after natural disasters, not so much in the long run.
    --

    The most expensive tool is the one you buy "cheaply" and often...

  6. #6
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    Anybody else put in a whole house panel surge protector? Easy to do.
    NOW you tell me...

  7. #7
    Quote Originally Posted by Ole Anderson View Post
    I guess my whole house panel surge protector and my premium power strips did their job.
    First, power interruptions are completely different from surges. View some numbers. Protectors do nothing until 120 volts well exceeds a let-through voltage: 330 volts. Does power restoration cause high voltages? Of course not. Power restoration is trying to repower everything all at once. So voltage only slowly rises from 0 to 120. It never exceeds 330 volts.

    Surge protectors do nothing for blackouts and brownouts. Blackouts do not harm any properly designed hardware. Brownout are only potentially harmful to motorized appliances.

    Second, apparently the blackout was caused by a surge. Two completely different anomalies. No protector must fail on any surge. Sacrificial protectors is a fable routinely promoted to the most naive consumers. The naive are experts when using what creates classic junk science - observation. Effective protectors remains functional for decades even after multiple direct lightning strikes.

    View numbers for a premium plug-in protector. How many joules does it claim to absorb? Potentially destructive surges are how many joules? That expensive protector is little different from one selling in Walmart for $10. And it does not even claim to protect from a type of current typically called a surge.

    Worse, if used without a 'whole house' protector, it may even make surge damage easier. Fire is another problem (threat). In short, premium means obscene profit margins and near zero protection.

    Third, only undersized protectors fail catastrophically. A minimal 'whole house' protector is 50,000 amps (because lightning is typically 20,000 amps). Those indicator lights only report catastrophic failure; when a protector is grossly undersized for that venue. Apparently a 100,000 amp protector may be necessary.

    Four, verify your 'primary' protection layer. Each protection layer is only defined by its earth ground. Your 'whole house' protector is effective because it connects low impedance (ie less than 10 feet) to single point earth ground. That is a 'secondary' protection layer.

    Pictures (not text) about half way down in this citation demonstrate what to inspect in the 'primary' protection layer. View pictures after the expression "more safety hazards" at:
    http://www.fpl-fraud.com/

    Five, that elevator cannot be effectively protected by a protector on it. That three phase protector must do what your 'whole house' protector also does. It must be located to make a low impedance (ie less than 10 foot) connection to the building's single point earth ground. Every foot farther from earth ground only compromises protection. Increased separation between protector and elevator increases protection.

    Six, mythical is "sensitive electronics". An expression often found where people are educated by scams. Protection inside electronics is some of the most robust. For example, many UPS output 'dirtiest' power when in battery backup mode. This power is potentially harmful to motorized appliances and power strip protectors. Those are the 'sensitive appliances'. That same 'dirty' UPS power is ideal for electronics. Because electronics are routinely more robust.

    "Sensitive electronics" is promoted by methods that identify scams. For example, what number defines "sensitive". No numbers is the first indication of a scam. Always demand specification numbers.

    A minimal 'whole house' protector is 50,000 amps. That number defined protector life expectancy over many surges. A protector is only as effective as its earth ground. That means a low impedance connection and upgraded earthing electrodes. Those numbers define protection during each
    surge.
    Last edited by Wes Thom; 09-22-2017 at 12:24 PM.

  8. #8
    Quote Originally Posted by Jim Becker View Post
    One of the serious national infrastructure changes that has to be brought forward is eschewing arial transmission in favor of underground routing,
    BBC would often note this in reports on FL hurricane damage. Americans still put wires overhead.

    Underground wires mean failures only occur randomly and less often. Not all at once.

    However underground does nothing to protect from anomalies such as surges. Same surge protection for overhead wires must also be installed for underground service. That threat is remains same. Potentially destructive incoming current is same; must be earthed BEFORE entering a building.

  9. #9
    Quote Originally Posted by Jim Becker View Post
    ... underground routing, .... Expensive, yes. ...
    A bit like free health care - all we have to do is pay for it!

  10. #10
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    Wes, interesting site you referenced.

    So what's are your thoughts on whole panel protectors for a home?

    For the elevator, our electrician recommended a $500 commercial 3 phase Intermatic rated at 50,000 amps. I chatted with an Intermatic rep that recommended an $1100 modular surge protector rated at 80,000 amps. Our only three phase equipment is the elevator and it goes straight from an outside 200 amp disconnect 20 feet from the transformer to the mechanical room panel.
    Last edited by Ole Anderson; 09-22-2017 at 8:06 PM.

  11. #11
    Quote Originally Posted by Ole Anderson View Post
    So what's are your thoughts on whole panel protectors for a home?
    If not yet obvious, its all about the quality of and connection to earth ground. Too many concentrate on the magic box when that connection to and quality of earth ground is far more important.

    For example, if that hardwire to earth is inside metallic conduit, then protection is compromised. That and other described characteristics - especially impedance - determine protection during each surge.

  12. #12
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    Does your power company have a contract for supply? Our mob has a basic agreed delivery reliability contract. If they fail to supply, they have to pay me. If I lose my freezer contents through their failure to supply, they have to pay. If a surge burns out my wiring, they have to pay. It doesn't even have to go to court, it's just basic contract law. When I get my bill, I have to pay. That's my side of the agreement. And we have the cheapest power in Australia. Last month we were having regular surges at 4.10pm every day in our shop that was just enough to trip out all 24 cnc machining centres mid flight. After the third one we called Aurora, they came out and tested everything within 15 minutes and found a dodgy neutral on a pole down the road. Problem solved and the next bill will have a discount. Hitting them in the hip pocket does wonders for reliability. Cheers

  13. #13
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    No we don't. But if we insisted on it, the Public Service Commission would grant them a rate increase to cover their costs, plus a nominal profit on the cost. And you can bet it is covered in your electric rates too. Nothing is free.
    NOW you tell me...

  14. #14
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    You are right nothing is free. It's just that companies operating in essential services have our governments looking over their shoulders. All price rises have to be applied for and fully justified before being granted. It still comes back to the contract though. We sign up to buy and they agree to supply. Whichever party fails their contractual obligations gets their a....e kicked. Being one of the less wealthy members of society, I have felt the boot sinking in when I haven't paid on time... Cheers

  15. #15
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    Quote Originally Posted by Jim Becker View Post
    One of the serious national infrastructure changes that has to be brought forward is eschewing arial transmission in favor of underground routing, particularly in areas prone to failure due to wind and weather damage. Expensive, yes. But considering the great cumulative cost of restoring power after natural disasters, not so much in the long run.
    The local Rural Electric Cooperative where I grew up put all their single phase distribution lines underground 45 years ago. That was out on the prairie of Western Minnesota, where ice storms, blizzards and tornados all contributed a fair share to power distribution system disruption. They initially had issues with some cable that wasn't pocket gopher proof, although that was fixed pretty soon after they started burying and discovered the issue. Weather related disruptions to my folk's power have been minimal in the nearly 5 decades since.

    It is interesting though to see the crews attack a cable failure in January when the ground is frozen 4+ feet deep. Early on, their ability to precisely locate the problem wasn't perfect, and a lot of HARD digging could ensue. Nowadays, they can locate to within a couple of feet where the open or leak is, and they've got equipment to deal with the frozen soil.

    Meanwhile, where I live, everything is still above ground, and we (our electric company is a consumer owned cooperative) spend millions per year cutting trees in the hopes that a wind or ice storm won't take out the power. Trees grow like weeds here. It's a game you can't win. You need a special dispensation from the REC engineering staff even to bury the "last mile" of distribution that is on your own property. Too much line loss, he says, in buried 14.4KV coax.

    In Korea, they are switching to DC mid-voltage distribution lines, so they bury them without incurring excessive loss.

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