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Thread: 5 homes burn after POCO connects power after hurricane

  1. #1
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    5 homes burn after POCO connects power after hurricane

    So here in Florida after the hurricane the neighborhood I'm working in. The POCO fired the tranny back up before the grounded conductor was connected or something along those lines( not sure what the whole story is). 5 homes caught on fire, one a complete loss. So I'm wondering how this can be prevented. I see it from time to time on a service call where the cable has carried the current and burnt cable jacks and such. I'm think a ground fault main would prevent this. Thoughts?

  2. #2
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    It could be the neutral was not connected before they energized the transformer, then again a loose or a disconnected neutral causing a whole house fire??? I don't know.

    Here the POCO usually will turn the main breaker OFF before connecting the over head service and will check for proper voltage before engaging the meter. And they will not turn the main breaker back ON.
    Edward
    The only thing I know, is the progressive discovery of my ignorance


  3. #3
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    Quote Originally Posted by electricblue View Post
    So here in Florida after the hurricane the neighborhood I'm working in. The POCO fired the tranny back up before the grounded conductor was connected..
    Primary distribution voltage may have blew up houses if a secondary transformer was shorted, or got crossed with grounded conductor?
    Roger Ramjet NoFixNoPay

  4. #4
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    Short circuits do not cause fires most of the time. Fuses and breakers blow when things get shorted. What starts fires in homes are loosened connections that do not get noticed, getting temps higher than normal which could ignite materials in the vicinity.

    My first job as a lineman involved clearing feeders after typhoons. The POCO which Im working with has a strict instruction never to go beyond the meters! That said, whatever happens after energization of the cleared feeders, we don't feel responsible,imo.

  5. #5
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    Quote Originally Posted by topgone View Post
    Short circuits do not cause fires most of the time. Fuses and breakers blow when things get shorted. What starts fires in homes are loosened connections that do not get noticed, getting temps higher than normal which could ignite materials in the vicinity.

    My first job as a lineman involved clearing feeders after typhoons. The POCO which Im working with has a strict instruction never to go beyond the meters! That said, whatever happens after energization of the cleared feeders, we don't feel responsible,imo.
    But a lost/unconnected neutral can send enough current through a powered on device to cause it to burn. For a small to medium load this would not even need to draw a maximum current from the branch circuit, let alone enough to blow a breaker.

    The only protection against that is to make sure the main is open at all connected buildings before energizing the service transformer.

    Sent from my XT1585 using Tapatalk

  6. #6
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    Were the 5 homes the ONLY ones on the xfmr?

    how would i flow with no neutral?
    I suppose you could get 240 across 120'devices
    Last edited by Ingenieur; 10-09-17 at 08:36 PM.



  7. #7
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    Quote Originally Posted by Ingenieur View Post
    Were the 5 homes the ONLY ones on the xfmr?

    how would i flow with no neutral?
    I suppose you could get 240 across 120'devices
    Exactly. If the loads on each leg are balanced, no problem. If not - BRBQ time.

  8. #8
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  9. #9
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    Quote Originally Posted by Ingenieur View Post
    Were the 5 homes the ONLY ones on the xfmr?

    how would i flow with no neutral?
    I suppose you could get 240 across 120'devices
    Most likely

  10. #10
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    Quote Originally Posted by GoldDigger View Post
    But a lost/unconnected neutral can send enough current through a powered on device to cause it to burn. For a small to medium load this would not even need to draw a maximum current from the branch circuit, let alone enough to blow a breaker.

    The only protection against that is to make sure the main is open at all connected buildings before energizing the service transformer.

    Sent from my XT1585 using Tapatalk
    Hence the reason our POCO (PG&E) will not turn ON the main breaker and will not even energize the meter if the reading are not correct at the meter jaw.
    Edward
    The only thing I know, is the progressive discovery of my ignorance


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