Machine Lockout Tagout

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youngdoug

New member
I work at an commercial plant and the machine operators (unqualified) are allowed to go into electrical cabinets to reset overloads and change out fuses. My question is, can unqualified machine operators go into the machine electrical panels if they are locked out? Any clarification would be appreciated.
 

zog

Senior Member
Location
Charlotte, NC
I work at an commercial plant and the machine operators (unqualified) are allowed to go into electrical cabinets to reset overloads and change out fuses. My question is, can unqualified machine operators go into the machine electrical panels if they are locked out? Any clarification would be appreciated.

"Qualified" is something only the employer can determine in this example. Nothing says you need to be an electrician. An operator or an electrican need to have the same training for that specific peice of equipment (Hazards, operation of equipment, PPE requirements, etc) to be considered "qualified". Your employer can train that operator on that specific equipment and task and deem tham "Qualified".

Look at the OSHA and/or NFPA 70E definition of a qualified person as it applies to LOTO.

Changin fuses requires some knowledge of faults and how to determine if the equipment is safe to re-energize IAW OSHA 1910.334, just replacing fuses without checking anything is an OSHA violation no matter who does it.

As far as working on LOTO equipment, once it has been properly placed in an "Electrically safe working condition" anyone can work on it.
 

pfalcon

Senior Member
Location
Indiana
Zog addressed what it takes to be qualified.

Your management should be aware that they will be held accountable for injuries if they do not adequately screen for qualification. Further they will disqualify themselves for numerous exceptions industry receives by restricting access to a trained and qualified staff.

An example is the use of a disconnecting means located at lighting under 410.130 (G). This is targeted at retail stores and small shops that may not maintain an onsite electrician. Exception No. 4 saves a bunch of money on lighting with a qualification program.
 

Don S.

Member
Who preformed the LOTO (lock out / tag out) and verified that the power was really off? It is supposed to be a LOTO qualified Electrician, and if so why doesn?t he reset or re-fuse while he is right there? If this reset / re-fuse activity is routine, something is wrong with the machine or the operator.
 

TxEngr

Senior Member
Location
North Florida
Since the lockout verification can be a bump test of the equipment, it is not necessary to open the door to the equipment. Similarly, the overload reset is on the front of the door. And like Zog said, a Qualified person is someone who has been trained on the equipment, the hazards, and the means to eliminate the hazards - it doesn't have to be an electrician. So the LOTO can be performed by the operations personnel and is frequently done in smaller plants who may only have one multicraft mechanic per shift. The key is the training of the people and documentating that training.
 

Don S.

Member
Youngdoug stated that the machine operators were permitted to go into the cabinets. A bump test does not confirm that all 3 phases have been disconnected. It is not a reliable method to verify something is electrically safe.
 

sii

Senior Member
Location
Nebraska
I have spent the last year trying to make my employer understand this topic. It is very similar to beating your head against a brick wall. They just don't get it.
 

TxEngr

Senior Member
Location
North Florida
I agree that a bump test does not test for presence of voltage but it is allowed by the code (both OSHA and NFPA70E) as a verification test for removal of energy. It may not be reliable in many peoples opinion - but it is allowed.

As to the going into cabinets to change out fuses, that's another matter and requires both tranining, knowledge, and PPE to perform properly. I can only assume they are using their shift maintenance to do the absence of power test in that case unless they can show that the operators have had the training and tools necessary to perform this work.
 
I have spent the last year trying to make my employer understand this topic. It is very similar to beating your head against a brick wall. They just don't get it.


I wonder whose head is harder, your boss, or you for banging it against the brick wall for a year? ;):D


There are so many documented cases of an employer who does not care...it will take an incident that brings OSHA to the plant to get changes made.
Hint, Hint!!!
 

jim dungar

Moderator
Staff member
Location
Wisconsin
Occupation
Retired Electrical Engineer - Power Systems
I agree that a bump test does not test for presence of voltage but it is allowed by the code (both OSHA and NFPA70E) as a verification test for removal of energy. It may not be reliable in many peoples opinion - but it is allowed.
A bump test meets the OSHA requirements for LOTO when 'mechanically' servicing the equipment. A bump test is not a sufficient LOTO test for an NFPA 70E 'electrical' de-energization of the equipment.

Two different procedures and end results, even though they share a common name - LOTO.
 

zog

Senior Member
Location
Charlotte, NC
I agree that a bump test does not test for presence of voltage but it is allowed by the code (both OSHA and NFPA70E) as a verification test for removal of energy. It may not be reliable in many peoples opinion - but it is allowed.

The "bump" test is allowed as verification (120.2(e)) but the LOTO process is not complete, the next required step in both 70E and OSHA is testing, your LOTO is not complete until you test for absence of voltage(120.2(f)), and in some cases, grounding (120.2(g))
 

Don S.

Member
TxEngr,

Just because something is permitted by OSHA or the NEC does not insure the practice will not kill you. Too many people think following rules and regulations is an adequate substitute for thoroughly understanding what you are working with and what you are doing. I personally have seen both a 5KV and a 15KV switch fail to open one of their phases. The transformers they were feeding stopped humming indicating the power to be off?? If a qualified Electrician had not been acting prudently, visually checking the switch blades before even thinking of testing for voltage, death could have been the result.
 

TxEngr

Senior Member
Location
North Florida
Jim nailed it when he stated that there is a difference in a lockout for mechanical service and one for electrical service. The testing step (120.2(F)(2)(f) spcifically states requires a "test before touching every exposed conductor or circuit part..." . If an operator is not "touching" an exposed conductor, then is the test required? But when changing a fuse, unless he is using the proper tool, he is likely to touch the conductor so the testing would be required.

Don - I too have seen the fingers of a switch weld in giving the illusion of de-energized. That's why my requirement is for a visual verification or electrical testing. Be it a 480V disconnect switch or a 4160V starter, visual verification of the fingers releasing from the stabs is requirement for me.

I don't want people to think I work in an unsafe manner. In the plant where I work, we often have more stringent requirements than the code. I agree with much of the opinion cited about safe actions. My concern here is that opinion is sometimes cited as the rule. I agree we want to be the safest we can. But if we start saying things like you must wear PPE for any switching operation on any interaction, then that rule would include switching a 120V light switch and that's just silly. Establish what the base rules are and then cite opinion about what is safest.
 

Don S.

Member
TxEngr, I agree, there is a potential problem of perfectly sensible rules for a specific application being misunderstood, by well meaning, but electrically ignorant people. I deal with that routinely. I also agree that a bump test is probably ok to verify that mechanical action has been secured, example for changing a belt. I didn?t know I could be so agreeable. By the way I?m in South FL.

The human brain is the most effective, yet most under-used safety device.
 

Don S.

Member
TxEngr, I agree, there is a potential problem of perfectly sensible rules for a specific application being misunderstood, by well meaning, but electrically ignorant people. I deal with that routinely. I also agree that a bump test is probably ok to verify that mechanical action has been secured, example for changing a belt. I didn?t know I could be so agreeable. By the way I?m in South FL.

The human brain is the most effective, yet most under-used safety device.
 
TxEngr, I agree, there is a potential problem of perfectly sensible rules for a specific application being misunderstood, by well meaning, but electrically ignorant people. I deal with that routinely. I also agree that a bump test is probably ok to verify that mechanical action has been secured, example for changing a belt. I didn’t know I could be so agreeable. By the way I’m in South FL.

The human brain is the most effective, yet most under-used safety device.

So how one would know that the bump-test - I prefer to call it bum-test - produced a negative result because an interlock was preventing the start?
 
29CFR1910.147(d)(6) Verification of Isolation.

It reads:

Verification of isolation. Prior to starting work on machines or equipment that have been locked out or tagged out, the authorized employee shall verify that isolation and deenergization of the machine or equipment have been accomplished.

The point was that the poster of the original maintained that a bump-test is an acceptable form of verification an identified as such in the cited Standards. As one can see above the cited paragraph does not state that.
 

jim dungar

Moderator
Staff member
Location
Wisconsin
Occupation
Retired Electrical Engineer - Power Systems
It reads:

Verification of isolation. Prior to starting work on machines or equipment that have been locked out or tagged out, the authorized employee shall verify that isolation and deenergization of the machine or equipment have been accomplished.

The point was that the poster of the original maintained that a bump-test is an acceptable form of verification an identified as such in the cited Standards. As one can see above the cited paragraph does not state that.

The general OSHA standards do not explicitly state exact steps that must be followed in a LOTO program as it is up to each employer to develop their own policies. However, 1910.147 APP A does list an example of procedures that are acceptable to OSHA and may be included in a LOTO program.
(7) Ensure that the equipment is disconnected from the energy source(s) by first checking that no personnel are exposed, then verify the isolation of the equipment by operating the push button or other normal operating control(s) or by testing to make certain the equipment will not operate.

Caution: Return operating control(s) to neutral or "off" position after verifying the isolation of the equipment.
 
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