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Thread: Working on PV systems over 600VDC

  1. #1
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    Working on PV systems over 600VDC

    I work for a Solar O&M company and my company is requiring all work done on equipment over 600V to have two people per OSHA. I am the only one in my state and this isn't feasible. What I would like to know if there are any exceptions to the rule?

    Thanks,
    Aaron

  2. #2
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    Quote Originally Posted by AaronWood2008 View Post
    I work for a Solar O&M company and my company is requiring all work done on equipment over 600V to have two people per OSHA. I am the only one in my state and this isn't feasible. What I would like to know if there are any exceptions to the rule?

    Thanks,
    Aaron
    You are the only what in your state?

  3. #3
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    I presume he means he's the only employee of his company in his state.

    Aaron, read this:
    https://www.osha.gov/laws-regs/stand...s/2001-08-27-1

    To my reading there's a lot of O&M work you could do by yourself, especially if you can denergize what you're working on. Repairing damaged string wiring could be an issue.

  4. #4
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    Seems like you can do all the O&M work that does not involve exposure to energized 600V+ circuits. That would seem to cover a lot but possibly not all O&M work you would have to do. You really do want two people there for some jobs.

  5. #5
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    For some jobs you may need to consider a part timer or a temp worker. In either case they would need to be "qualified" in the OSHA sense, even if you have to train them yourself.

  6. #6
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    Quote Originally Posted by GoldDigger View Post
    For some jobs you may need to consider a part timer or a temp worker. In either case they would need to be "qualified" in the OSHA sense, even if you have to train them yourself.
    I think they might need to be cpr trained as well.
    Bob

  7. #7
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    Isolate and Ground

    Seems the answer is two fold:
    (1) deenergize all AC circuits in the vicinity of the equipment you are working on.
    (2) Ground & short all AC and DC circuits to eliminate all voltage. (Just like good practice on medium-voltage systems.)

    Obviously, you cannot stop PV modules from generating current but they can be shorted to reduce the voltage to near zero. PV DC wiring is required by NEC to be sized to operate safely under a short circuit. Unless the module manufacturer prohibits shorting the DC circuit, this seems a viable way to achieve voltages below 600V.

    Once LOTO and short/ground is completed using appropriate tools, there are no voltages over 600V present.
    e^(i pi) = -1

  8. #8
    Join Date
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    Quote Originally Posted by beanland View Post
    Seems the answer is two fold:
    (1) deenergize all AC circuits in the vicinity of the equipment you are working on.
    (2) Ground & short all AC and DC circuits to eliminate all voltage. (Just like good practice on medium-voltage systems.)

    Obviously, you cannot stop PV modules from generating current but they can be shorted to reduce the voltage to near zero. PV DC wiring is required by NEC to be sized to operate safely under a short circuit. Unless the module manufacturer prohibits shorting the DC circuit, this seems a viable way to achieve voltages below 600V.

    Once LOTO and short/ground is completed using appropriate tools, there are no voltages over 600V present.
    Um, do you have any experience with PV source and output circuits? If not I suggest you stick to your expertise. Shorting PV circuits will produce arc flash if the sun is shining and I'm sure that's not how OSHA would like things to be done.

    Also if the work is troubleshooting, say, groundfault issues with PV source circuits, then shorting the circuit interferes with the work.

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