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Thread: Understanding Arc Flash rating requirement

  1. #1
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    Marietta , GA, Cobb county
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    Understanding Arc Flash rating requirement

    Hello, my name is Mike and I am a Maintenance Tech. I AM NOT AN ELECTRICIAN.

    I work on large pumps and motors. They are 1200HP 4160v. We had all of our switch gear rated and labeled, but I would like some clarification.
    I have gotten conflicting info about our Arc Flash ratings.

    I am trying to find out what PPE is required to operate the disconnect for the attached rated equipment.

    Please let me know if more information is required.
    Thank you

  2. #2
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    Mar 2005
    Location
    Hampton, VA
    Posts
    337
    Quote Originally Posted by MikeChaco View Post
    Hello, my name is Mike and I am a Maintenance Tech. I AM NOT AN ELECTRICIAN.

    I work on large pumps and motors. They are 1200HP 4160v. We had all of our switch gear rated and labeled, but I would like some clarification.
    I have gotten conflicting info about our Arc Flash ratings.

    I am trying to find out what PPE is required to operate the disconnect for the attached rated equipment.

    Please let me know if more information is required.
    Thank you
    Based on your question, you first need to determine if you are even qualified to work on this equipment. The NEC and NFPA 70E, Standard for Electrical Safety in the Workplace define qualified person as follows:

    Qualified Person. One who has demonstrated skills and
    knowledge related to the construction and operation of
    electrical equipment and installations and has received
    safety training to identify and avoid the hazards involved.

    Additionally, NFPA 70E states that a qualified person should be trained as follows:

    (1) Qualified Person. A qualified person shall be trained
    and knowledgeable in the construction and operation of
    equipment or a specific work method and be trained to
    identify and avoid the electrical hazards that might be
    present with respect to that equipment or work method.

    (a) Such persons shall also be familiar with the proper
    use of the special precautionary techniques, applicable electrical
    policies and procedures, PPE, insulating and shielding
    materials, and insulated tools and test equipment. A
    person can be considered qualified with respect to certain
    equipment and methods but still be unqualified for others.
    (b) Such persons permitted to work within the limited
    approach boundary shall, at a minimum, be additionally
    trained in all of the following:
    (1) Skills and techniques necessary to distinguish exposed
    energized electrical conductors and circuit parts from
    other parts of electrical equipment
    (2) Skills and techniques necessary to determine the nominal
    voltage of exposed energized electrical conductors
    and circuit parts
    (3) Approach distances specified in Table 130.4(D)(a) and
    Table 130.4(D)(b) and the corresponding voltages to
    which the qualified person will be exposed
    (4) Decision-making process necessary to be able to do the
    following:
    a. Perform the job safety planning
    b. Identify electrical hazards
    c. Assess the associated risk
    d. Select the appropriate risk control methods from
    the hierarchy of controls identified in 110.1(G),
    including personal protective equipment

    The last one includes knowing how to determine the correct PPE. If you don't know how to assess the hazard and select the appropriate risk control methods, including selecting the correct PPE, or if you haven't had electrical safety training, I would say you are not qualified to do the work and need to get electrical safety training as a minimum.

  3. #3
    Join Date
    Dec 2011
    Location
    Ocala, Florida, USA
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    2,186
    Quote Originally Posted by jtinge View Post
    Based on your question, you first need to determine if you are even qualified to work on this equipment. The NEC and NFPA 70E, Standard for Electrical Safety in the Workplace define qualified person as follows:

    Qualified Person. One who has demonstrated skills and
    knowledge related to the construction and operation of
    electrical equipment and installations and has received
    safety training to identify and avoid the hazards involved.

    Additionally, NFPA 70E states that a qualified person should be trained as follows:

    (1) Qualified Person. A qualified person shall be trained
    and knowledgeable in the construction and operation of
    equipment or a specific work method and be trained to
    identify and avoid the electrical hazards that might be
    present with respect to that equipment or work method.

    (a) Such persons shall also be familiar with the proper
    use of the special precautionary techniques, applicable electrical
    policies and procedures, PPE, insulating and shielding
    materials, and insulated tools and test equipment. A
    person can be considered qualified with respect to certain
    equipment and methods but still be unqualified for others.
    (b) Such persons permitted to work within the limited
    approach boundary shall, at a minimum, be additionally
    trained in all of the following:
    (1) Skills and techniques necessary to distinguish exposed
    energized electrical conductors and circuit parts from
    other parts of electrical equipment
    (2) Skills and techniques necessary to determine the nominal
    voltage of exposed energized electrical conductors
    and circuit parts
    (3) Approach distances specified in Table 130.4(D)(a) and
    Table 130.4(D)(b) and the corresponding voltages to
    which the qualified person will be exposed
    (4) Decision-making process necessary to be able to do the
    following:
    a. Perform the job safety planning
    b. Identify electrical hazards
    c. Assess the associated risk
    d. Select the appropriate risk control methods from
    the hierarchy of controls identified in 110.1(G),
    including personal protective equipment

    The last one includes knowing how to determine the correct PPE. If you don't know how to assess the hazard and select the appropriate risk control methods, including selecting the correct PPE, or if you haven't had electrical safety training, I would say you are not qualified to do the work and need to get electrical safety training as a minimum.

    Does operating a safety switch require PPE? I don't think so. In fact, one of the reasons it is there is to shut down equipment with moving parts in case of emergency need.


    I know what I don't know, and I know where to go to find it!

  4. #4
    Join Date
    Feb 2003
    Location
    Massachusetts
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    60,020
    Quote Originally Posted by Strathead View Post
    Does operating a safety switch require PPE?
    I believe it can be required.

    I don't think so. In fact, one of the reasons it is there is to shut down equipment with moving parts in case of emergency need.
    I disagree with that. The NEC requires the switch for servicing the equipment not as an emergency switch. We can lock the service switch on with a pad lock if we choose.

  5. #5
    Join Date
    Mar 2005
    Location
    Hampton, VA
    Posts
    337
    Quote Originally Posted by Strathead View Post
    Does operating a safety switch require PPE? I don't think so. In fact, one of the reasons it is there is to shut down equipment with moving parts in case of emergency need.
    My point was that if you had to ask, you probably were not qualified. A qualified person would have the skills and knowledge and the safety training to assess the hazard or lack thereof and determine if PPE was needed.

  6. #6
    Join Date
    Apr 2016
    Location
    Raleigh, NC USA
    Posts
    345
    Quote Originally Posted by jtinge View Post
    Based on your question, you first need to determine if you are even qualified to work on this equipment. The NEC and NFPA 70E, Standard for Electrical Safety in the Workplace define qualified person as follows:

    Qualified Person. One who has demonstrated skills and
    knowledge related to the construction and operation of
    electrical equipment and installations and has received
    safety training to identify and avoid the hazards involved.

    Additionally, NFPA 70E states that a qualified person should be trained as follows:

    (1) Qualified Person. A qualified person shall be trained
    and knowledgeable in the construction and operation of
    equipment or a specific work method and be trained to
    identify and avoid the electrical hazards that might be
    present with respect to that equipment or work method.

    (a) Such persons shall also be familiar with the proper
    use of the special precautionary techniques, applicable electrical
    policies and procedures, PPE, insulating and shielding
    materials, and insulated tools and test equipment. A
    person can be considered qualified with respect to certain
    equipment and methods but still be unqualified for others.
    (b) Such persons permitted to work within the limited
    approach boundary shall, at a minimum, be additionally
    trained in all of the following:
    (1) Skills and techniques necessary to distinguish exposed
    energized electrical conductors and circuit parts from
    other parts of electrical equipment
    (2) Skills and techniques necessary to determine the nominal
    voltage of exposed energized electrical conductors
    and circuit parts
    (3) Approach distances specified in Table 130.4(D)(a) and
    Table 130.4(D)(b) and the corresponding voltages to
    which the qualified person will be exposed
    (4) Decision-making process necessary to be able to do the
    following:
    a. Perform the job safety planning
    b. Identify electrical hazards
    c. Assess the associated risk
    d. Select the appropriate risk control methods from
    the hierarchy of controls identified in 110.1(G),
    including personal protective equipment

    The last one includes knowing how to determine the correct PPE. If you don't know how to assess the hazard and select the appropriate risk control methods, including selecting the correct PPE, or if you haven't had electrical safety training, I would say you are not qualified to do the work and need to get electrical safety training as a minimum.

    I agree. In my experience it has always been the employer that qualified the person. In my case, checking the box on training, being assigned safety equipment and having electrical tasks in ones job description almost always made the individual qualified up to Haz Cat 2. There was never a demonstration of skills or a skills test.

    I was a "qualified person" long before I held an electrical credential.

    What version of the NEC 70E is your employer using? We still use the 2012 version which is tasked base. We adopted a blanket statement that no employee may perform a task that is higher than Cat 2. From table 130.7(c)(15)(a) NEC 70E 2012 Edition: Metal Clad Switch Gear 1kV-38kV Max 35 kA short circuit current available, .2 sec clearing time etc. etc. : circuit breaker operation with doors closed is a Cat 2.

    Where it specifically rates a 1200 hp pump, meduim voltage disconnect..... I do not know.

    It is my understanding that the 2015 Edition is not tasked based and is based solely on available energy/arc risk. So your facility will have to have an arc analysis done and all equipment labeled with PPE requirements.

  7. #7
    Join Date
    Apr 2016
    Location
    Raleigh, NC USA
    Posts
    345
    Quote Originally Posted by MikeChaco View Post
    Hello, my name is Mike and I am a Maintenance Tech. I AM NOT AN ELECTRICIAN.

    I work on large pumps and motors. They are 1200HP 4160v. We had all of our switch gear rated and labeled, but I would like some clarification.
    I have gotten conflicting info about our Arc Flash ratings.

    I am trying to find out what PPE is required to operate the disconnect for the attached rated equipment.

    Please let me know if more information is required.
    Thank you

    Another question is .......what are you doing once the disconnect is down?

    Are you adjusting the packing? OR........

    Are you unwiring the motor?

    If you are exposing yourself to possibly live electrical parts..........you must have the proper meters and gear.....especially with 4160v. Testing for voltage on 4160 in the NFPA 70E 2012 edition is a Cat 4 EVEN if the disconnect is down!

  8. #8
    Join Date
    Mar 2005
    Location
    Hampton, VA
    Posts
    337
    Quote Originally Posted by Saturn_Europa View Post
    It is my understanding that the 2015 Edition is not tasked based and is based solely on available energy/arc risk. So your facility will have to have an arc analysis done and all equipment labeled with PPE requirements.
    The 2015 Edition did not eliminate tasks, it eliminated Hazard Risk Categories (HRC) and split them into a task table to determine if PPE is required or not and a table that tells you what PPE to use based on an Arc Flash PPE category. If an incident energy (IE) assessment has been made and documented on an arc flash hazard label, select PPE based on the IE shown on the label.

  9. #9
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    Aug 2004
    Location
    Northern illinois
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    15,266
    Quote Originally Posted by jtinge View Post
    A qualified person would have the skills and knowledge and the safety training to assess the hazard or lack thereof and determine if PPE was needed.
    In general I agree with this assessment.
    Bob

  10. #10
    Join Date
    Apr 2016
    Location
    Raleigh, NC USA
    Posts
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    Quote Originally Posted by jtinge View Post
    The 2015 Edition did not eliminate tasks, it eliminated Hazard Risk Categories (HRC) and split them into a task table to determine if PPE is required or not and a table that tells you what PPE to use based on an Arc Flash PPE category. If an incident energy (IE) assessment has been made and documented on an arc flash hazard label, select PPE based on the IE shown on the label.

    Thank you for the clarification.

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