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Thread: LOTO molded case breaker

  1. #11
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    Some kind of shaft lock instead of an electrical disconnect might be acceptable locking means for mechanical lockout on a motor driven machine.

    Might be poor design from the motor's perspective, but still protects the employee accessing the moving parts from accidental startup.

  2. #12
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    One thing worth adding here is that for us in the electrical trades, LO/TO is almost always just electrical. NFPA 70E is about electrical hazards. But LO/TO is an OSHA requirement and they refer to all forms of energy being removed. So if you have air, water, hydraulics or even flywheel energy, LO/TO of those sources is still required. The point being that what you asked, regarding needing LO/TO even if not doing electrical work, is exactly what LO/TO is all about, not just electrical. So the answer is yes, you need to do it.
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  3. #13
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    Quote Originally Posted by Jraef View Post
    One thing worth adding here is that for us in the electrical trades, LO/TO is almost always just electrical.
    Perhaps that's how many think of it. Please don't think I'm contradicting you. It is a risk if you are working on the electrical aparatus.

    My background as you probably know, is mainly industrial. I suppose the paper industry is as good an example as any. A paper (making) machine* has many moving parts which need regular maintenance. This requires the maintenance crew to get into the guts if the machinery to remove and replace parts.

    There is no way this would be allowed to happen without LOTO and a written permit to work. The risk is not electrical - it is physical. And that's what the OP seems to be looking at.

    *Big beast.
    Si hoc legere scis nimium eruditionis habes.

  4. #14
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    That was actually my point, it's NOT just an electrical issue, it's a general safety requirement when working on machinery.
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  5. #15
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    Quote Originally Posted by Jraef View Post
    That was actually my point, it's NOT just an electrical issue, it's a general safety requirement when working on machinery.
    Then I misunderstood your comment:

    LO/TO is almost always just electrical. NFPA 70E is about electrical hazards.
    For that, I apologise.
    Si hoc legere scis nimium eruditionis habes.

  6. #16
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    ...for us in the electrical trades, LO/TO is almost always just electrical.
    Context...
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  7. #17
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    No argument .. a LOTO is needed, my question goes back on how to implement them. Our current standard states we put the machine in an electrically safe condition... going back to NFPA70E we will verify that by using a meter (electrician). This has worked for us for the past 40 years, but we are a continuous process so we typically don't deal with daily jams. We are now starting to install packaging equipment and this is where the questions are being asked, how to properly lock out the machine to allow operations to set up / service and repair the machine (with out calling an electrician). The debate is .. does our standard need to be revised to have two type of lock outs... electrical and operational? If we do an operational lock out ... what constitutes a verification the hazard has been removed? ... testing the start button? My reservation with that is the numerous interlocks that could be keeping a machine from starting that has nothing to do with a proper lockout.

    Our safety dept. will be doing a risk assessment and I hope to use some of the information from this thread in that discussion.

    Appreciate everyone replies.

  8. #18
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    Quote Originally Posted by cornbread View Post
    No argument .. a LOTO is needed, my question goes back on how to implement them. Our current standard states we put the machine in an electrically safe condition... going back to NFPA70E we will verify that by using a meter (electrician). This has worked for us for the past 40 years, but we are a continuous process so we typically don't deal with daily jams. We are now starting to install packaging equipment and this is where the questions are being asked, how to properly lock out the machine to allow operations to set up / service and repair the machine (with out calling an electrician). The debate is .. does our standard need to be revised to have two type of lock outs... electrical and operational? If we do an operational lock out ... what constitutes a verification the hazard has been removed? ... testing the start button? My reservation with that is the numerous interlocks that could be keeping a machine from starting that has nothing to do with a proper lockout.

    Our safety dept. will be doing a risk assessment and I hope to use some of the information from this thread in that discussion.

    Appreciate everyone replies.
    Some machines pressing start button and nothing happens is enough, others that may be interlocked with other things or even have self contained limits that lock things out may need additional evaluation on how to determine when it is in a safe condition, this means exact procedure can vary some from one machine to another.

  9. #19
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    Two verification procedures for the same equipment is quite common. One procedure for electrical work and one procedure for mechanical work. There is less confusion when you can use the one procedure for mechanical verification across all machines. The problem is with Try Start, as has already been indicated, it is often not conclusive and therefore not possible to use on all machines or in all circumstances. That is why some sites have reverted to voltage tests on the load side of disconnects, even for mechanical verification, as it works in most cases however it is time consuming and expensive. I suspect that is why there is confusion in industry that voltage tests are a requirement for all verification when I don't think that the evidence is there.

    This gives rise to the question - How can any worker perform a voltage test on the load side of a disconnect quickly, accurately and safely? This question has motivated many to develop LED voltage indicators. They are inherently quick and safe to use but unless recognized safety methods are employed, accuracy may be compromised. Safety methods require more than just dual LED indications or a reliance on the operator to initiate the voltage indication or claiming a SIL level. But that is another story altogether!

  10. #20
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    One personal experience at a pumping station. I was there doing unrelated wiring. The water techs are allowed to de-energize pumps by locking off the molded case breaker and tagging it. A lock isn't required if they are within sight of the breaker. But...an accident happened (injury was minor, thank God). The operator manually opened a solenoid operated hydraulic discharge valve, which allowed water to backflow from the tank uphill and cause the pump to rotate backwards at a pretty fast clip. The tech had gloves on and was undoing coupling bolts and got his hand jammed in the housing. So...the mechanical energy may still be there even when pushing a start control verifies no power. It's all about training.

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