This article was posted 04/29/2010 and is most likely outdated.

Toronto Dogs - Stray Voltage Continues
 

 

Topic - Stray Voltage
Subject - Toronto Dogs - Stray Voltage Continues

April 29, 2010
This newsletter was sent to 19287 newsletter subscribers

Ask a Question |  Continuing EducationQuizzes |  Free Stuff Instructors Products | Seminars | SubscribeUnsubscribe
[ image1 Post Comments | View Comments | Notify Me When Comments Are Added ]  

Sorry, Toronto dogs: Stray voltage problems won't go away

Image1
Posted: January 07, 2010, 6:30 AM by Rob Roberts

This enormous five-year-old Chesapeake Bay Retriever named Schroeder (he weighs close to 50 kilograms) was being walked on a Toronto street when he stepped on a small asphalt patch on the sidewalk and was shocked. This lucky dog lived to tell the tale!

After two dogs died from stray voltage last winter, Toronto Hydro last February did a month-long blitz with all its employees, and discovered 1,600 instances of contact voltage which they repaired. Toronto Hydro says that, despite its efforts (it has spent $14.4-million tracking and fixing stray voltage) this problem will continue to plague the city -- and threaten the dogs.

The main culprit are small “handwell covers” that house the wiring of street lights, a network that Toronto Hydro in 2005 took over from the City of Toronto. Toronto Hydro uses fibreglass for its new covers. Going forward, Hydro has contracted Power Survey Co., of New Jersey, which has three trucks permanently sweeping Toronto, searching for stray voltage.

Read the complete story.

 

 

Click here to post a comment

[ Post Your Comments | View Comments | Notify Me When Comments Are Added ]
[ View More Newsletters ]

Bookmark and Share


Copyright © Mike Holt Enterprises, Inc. All rights reserved.
This article is protected by United States copyright and other intellectual property laws and may not be
displayed or published on the internet without the prior written permission of Mike Holt Enterprises, Inc.

http://www.MikeHolt.com     1-888-NEC-CODE (1-888-632-2633)

 

 
Comments
  • To all theoretical and practical electrical engineers,

    What I sent to Mike Holt’s Forum is a very important question that needs to be answered immediately. Anyone who touches the metal street light pole or traffic pole with stray voltage will get an electric shock. This problem needs to be solved. Remember, all people in the United States including electrical engineers are waiting for an answer.

    Existing lamppost has no grounding rod, but has four anchor rods encased in cement. Adding a grounding rod is not possible in New York City because of all the underground infrastructure. If it was possible though, doesn’t this just add a second potential?

    Would isolation transformer help if neutral was not connected to pole in any way? 88% of the stray voltage poles are from failed and unbalanced neutrals. If not how is this application different from the use in hospital or staging application of isolation transformers?

    You haven’t given an answer to my question. Your answer is not clear and to the point.

    My Question Your Answer My Comments A. Stray voltage What do you mean stray voltage? Stray voltage on metal street light pole or traffic pole 1. Grounding and bonding Follow the Code Not a practical answer 2. Isolation transformer, it doesn’t help, why? Isolation transformer won’t solve an energized pole hazard You didn’t provide the answer “why” (see attached drawing) 3. Bracket with luminaire on wood pole should be grounded You didn’t answer See attached drawing B. Size of fuse for street light luminaire(s) Fuse are optional (recommended) Not a practical answer C. Size of wire for street light luminaire(s)

    100-watt luminaire, 150-watt luminaire, 250-watt luminaire (120-volt); Not a practical answer

    What I need is a concrete answer! Please don’t inform me to search the rest of the Internet for answer.

    Yakov Shmayevich

    Yakov Shmayevich
    Reply to this comment

  • To all theoretical and practical electrical engineers,

    What I sent to Mike Holt’s Forum is a very important question that needs to be answered immediately. Anyone who touches the metal street light pole or traffic pole with stray voltage will get an electric shock. This problem needs to be solved. Remember, all people in the United States including electrical engineers are waiting for an answer.

    Existing lamppost has no grounding rod, but has four anchor rods encased in cement. Adding a grounding rod is not possible in New York City because of all the underground infrastructure. If it was possible though, doesn’t this just add a second potential?

    Would isolation transformer help if neutral was not connected to pole in any way? 88% of the stray voltage poles are from failed and unbalanced neutrals. If not how is this application different from the use in hospital or staging application of isolation transformers?

    You haven’t given an answer to my question. Your answer is not clear and to the point.

    My Question Your Answer My Comments A. Stray voltage What do you mean stray voltage? Stray voltage on metal street light pole or traffic pole 1. Grounding and bonding Follow the Code Not a practical answer 2. Isolation transformer, it doesn’t help, why? Isolation transformer won’t solve an energized pole hazard You didn’t provide the answer “why” (see attached drawing) 3. Bracket with luminaire on wood pole should be grounded You didn’t answer See attached drawing B. Size of fuse for street light luminaire(s) Fuse are optional (recommended) Not a practical answer C. Size of wire for street light luminaire(s)

    100-watt luminaire, 150-watt luminaire, 250-watt luminaire (120-volt); Not a practical answer

    What I need is a concrete answer! Please don’t inform me to search the rest of the Internet for answer.

    Yakov Shmayevich

    Yakov Shmayevich
    Reply to this comment

  • Too bad about the dog that received a shock. Too bad also that people mistakenly lablel an energized piece of equipment as "stray voltage". For example, if a manhole becomes energized with 120 volts this is not stray voltage. It is "a manhole energized with 120 volts" which is a contact voltage. On the other hand, stray voltage is the natural voltage that occurs between grounded objects because of voltage drop between them. In some cases this "stray voltage" can reach levels which is objectional. They voltages are typically under ten volts.

    Dave K
    Reply to this comment

  • Stray voltage is generally regarded as being below 10 volts as correctly stated by Dave K.

    Voltages above 10 volts are generally considered to be fault currents (volts x amps = current) or leakage currents both which should be corrected immediately to prevent death or injury.

    The term used in the above answer by Dave K is somewhat misleading in that stray voltage is not the "natural voltage"; it is "manmade voltage" and not natural.

    DC voltage may be manmade or naturally occurring.

    In a multi-grounded wye distribution, earth is used as a conductor in parallel with the primary neutral.

    The intentional grounding of the primary neutral to earth, creates "earth currents", nature did not create them. Man created this condition.

    The multi-grounded wye distribution system is the only commonly used distribution system that creates "stray voltage" by design. This is clearly stated in CRN 2002 and NEETRAC 2008.

    Chuck Untiedt
    Reply to this comment

  • Stray Voltage and the Toronto Dogs... sounds like a good name for a band!

    Kevin Mathews
    Reply to this comment


Get notified when new comments are posted here
* Your Email:
 
        
 
Add Your Comments to this Newsletter
* Your Name:
   Your name will appear under your comments.

* Your Email:
   Your email address is not displayed.
* Comments:

Email Notification Options:
Notify me when a reply is posted to this comment
Notify me whenever a comment is posted to this newsletter