Lock out Tag out verification

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cornbread

Senior Member
Looking for some input on how others verify you have a proper lock out? NFPA 70E states verify the equipment can not be restarted by means of a push button, selector switch... other electrical means. That approached work many years ago when we had simple 3 wire controls. Today , at least where I work we have DCS stops, Load controls interlocks, thermal cut out, flow, pressure... you name it we have interlocks for it. If we do a lock out and push the start button on the motor does not start, could or could not be a good lock out, could be held from starting via a interlock.

We talked in house about using a push to test pilot light at the start/stop station as indication that power has been removed? Costly to do that, so looking for any suggestions of insight on how others verify a proper lock out. As always you help and comments are greatly appreciated.
 

don_resqcapt19

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Location
Illinois
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retired electrician
At a plant I often do work at, we added Hand-Off-Auto Switches at all of the motors for this purpose. The hand position bypasses all controls and interlocks with the exception of the starter overload relay. The hand position is spring return to off so you cannot leave the motor running with the controls and interlocks bypassed.

The procedure is for you to try to run the motor in hand, then go lock out the starter and return to the motor and try it in hand again.
Of course if you are going to work in the wiring itself, you still have to verify that it is de-energized by using a meter and the live-dead-live test procedure.
 

cornbread

Senior Member
We had the local remote switches also, but as our equipment and processes have evolved, we find ourselves interlocking the equipment more and more. Our safety guys will give us guidance that under these conditions the equipment can not run, so we typically have the DCS stop moved in front of the local remote switch. We also have equipment vendors that will tell us to never run the equipment if certain conditions exist, same thing where we have the controls stop ahead of the LR switch On our larger equipment we have sequenced controls that will start the oil pumps, manipulate valves and only when all these conditions are met do we start the equipment.
 

just the cowboy

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newburgh,ny
Do the best you can

Do the best you can

This has always been an issue, the how do you know you tested it part of lockout-tagout. When an operator had to clear a jam and they broke the plain of the machine reaching in they had to lockout the machine. They would pull the disconnect and press the start button the verify it would not start. But the argument was that it was in a jam condition and it could not start due to the jam switch, how do you verify it? For jam clearing they set a policy of maintenance to insure disconnects work, operator would listen for disconnect opening, and so on. For maintenance on the machine an electrician would have to verify that the blades opened, we replaced any of the sliding type with blade type disconnects. But good planning and procedures need to be done.
 

Strathead

Senior Member
Location
Ocala, Florida, USA
Occupation
Electrician/Estimator/Project Manager/Superintendent
Looking for some input on how others verify you have a proper lock out? NFPA 70E states verify the equipment can not be restarted by means of a push button, selector switch... other electrical means. That approached work many years ago when we had simple 3 wire controls. Today , at least where I work we have DCS stops, Load controls interlocks, thermal cut out, flow, pressure... you name it we have interlocks for it. If we do a lock out and push the start button on the motor does not start, could or could not be a good lock out, could be held from starting via a interlock.

We talked in house about using a push to test pilot light at the start/stop station as indication that power has been removed? Costly to do that, so looking for any suggestions of insight on how others verify a proper lock out. As always you help and comments are greatly appreciated.

When you are referring to motors, which it sounds like you are, and code requires every one to be provided with a disconnecting means, why would you just remove power and secure the disconnect?
 

don_resqcapt19

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Location
Illinois
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retired electrician
When you are referring to motors, which it sounds like you are, and code requires every one to be provided with a disconnecting means, why would you just remove power and secure the disconnect?
Because there is an exception for industrial locations that permits the disconnect to be remote from the motor. Anytime the disconnect is remote you are have to rely on the tagging and that can be an issue.

I think if I had a choice I would use Meltric connections on newly installed motors.
 

Strathead

Senior Member
Location
Ocala, Florida, USA
Occupation
Electrician/Estimator/Project Manager/Superintendent
Because there is an exception for industrial locations that permits the disconnect to be remote from the motor. Anytime the disconnect is remote you are have to rely on the tagging and that can be an issue.

I think if I had a choice I would use Meltric connections on newly installed motors.


But they have to be present and lockable.
 

don_resqcapt19

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retired electrician
But they have to be present and lockable.
The disconnects installed per the exception are not with in sight from the motor so there is no way to positively identify that you have turned the correct disconnect off. You have to assume that the marking on the remote disconnect is correct...something you really shouldn't do for a lock out.
 

kentirwin

Senior Member
Location
Norfolk, VA
Written Procedures

Written Procedures

OSHA 1910.147, the control of hazardous energy, dictates that for other than simple lockout an equipment specific written procedure must be developed and specifically trained on in order for anyone to be qualified to lock out that piece of equipment. And as with all things OSHA everything must be documented. Simple lockout is where there is only one form of hazardous energy to be isolated, eg. a single disconnect switch kills everything.
 

Strathead

Senior Member
Location
Ocala, Florida, USA
Occupation
Electrician/Estimator/Project Manager/Superintendent
The disconnects installed per the exception are not with in sight from the motor so there is no way to positively identify that you have turned the correct disconnect off. You have to assume that the marking on the remote disconnect is correct...something you really shouldn't do for a lock out.

Respectfully, if you want to get in to "what if's" that creates a whole new twist. In fact with the "what if" you can just as easily apply your argument to a marked disconnect right beside the piece of equipment, as in no guarantee that it is for that piece of equipment. If the disconnects are labeled, then for purposes of locking out and then testing the incoming power to the location, that is enough for me. You can trace conduit, etc. It never alleviates my guys from taking out their voltage tester, testing on a known live source and then testing the circuit. I encourage the use of a pen tester but again not a substitute for the voltmeter, just another layer. The whole reason (in my opinion) the code makes the exceptions for industrial situations is because they assume that a competent person will be in charge of the maintenance at a facility.
 
Looking for some input on how others verify you have a proper lock out? NFPA 70E states verify the equipment can not be restarted by means of a push button, selector switch... other electrical means. That approached work many years ago when we had simple 3 wire controls. Today , at least where I work we have DCS stops, Load controls interlocks, thermal cut out, flow, pressure... you name it we have interlocks for it. If we do a lock out and push the start button on the motor does not start, could or could not be a good lock out, could be held from starting via a interlock.

We talked in house about using a push to test pilot light at the start/stop station as indication that power has been removed? Costly to do that, so looking for any suggestions of insight on how others verify a proper lock out. As always you help and comments are greatly appreciated.

Many take the view for the above reasons that you really need to verify that the disconnect is off rather than rely on Try Start. That way you don't need to worry about control circuit elements or jammed machinery. If the reason for the lockout involves non electrical work then possible solutions for verification include visual breaks (plug/socket, visible blades), visual indication (load side pilot lights) and a voltage indicator LEDs with self test function.

Plug/Socket and visible blades while simple, have many practical and cost disadvantages. Load side pilot lights are cheap but they do not incorporate positive indication (ie illuminated when the power is off), introduce a weak point in the power system and self testing (test the tester) is not usually possible.
 

meternerd

Senior Member
Location
Athol, ID
Occupation
retired water & electric utility electrician, meter/relay tech
As a utility, we have LO/TO classes all the time. Technically called "Energy Source Control" classes. A written procedure has to be provided. That procedure has to be written by "qualified persons" and tested for effectiveness. From the smallest podunk POCO to the nuclear plants, the procedure is pretty much the same. Violating a LO/TO tag is a firable (is that a word?) offense. If anything bad happens, that's likely what OSHA will ask for first. We do not consider On/Off switches to be enough. Breakers off and tagged, valves shut and tagged, springs discharged...the list goes on.
 

GoldDigger

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Placerville, CA, USA
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The standard usage is "firing offense", but that does not have the same room for case by case judgement that " firable" would have if only it were a word. :)
 

rsmike

Member
We LOTO things using physical locks. We do NOT have a TO program. ( I suppose technically we have a LO program and not a LOTO program)... We have a documented program and training for everyone in the facility. Awareness training for those that are in the area. More advanced training for qualified people.

We also have complex LOTO procedures. Most all are documented on a per machine basis. I like to think we have things idiot resistant to keep people safe.

If you are needing to verify the power is off before opening the cabinet there is a product that Grace Engineering makes that provides visual as well as noncontact test points. This would help eliminate the need for a voltage test to verify power is off before opening a cabinet while wearing required PPE.

RSlater,
RSmike
 

don_resqcapt19

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Location
Illinois
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retired electrician
....

If you are needing to verify the power is off before opening the cabinet there is a product that Grace Engineering makes that provides visual as well as noncontact test points. This would help eliminate the need for a voltage test to verify power is off before opening a cabinet while wearing required PPE.

RSlater,
RSmike
While that sounds great, as far as I know OSHA does not accept that device to verify that the equipment has been de-energized.
 
If you are needing to verify the power is off before opening the cabinet there is a product that Grace Engineering makes that provides visual as well as noncontact test points. This would help eliminate the need for a voltage test to verify power is off before opening a cabinet while wearing required PPE.

Could these devices introduce a weak point in your power system? Best to check the over voltage category on them before installing.
 

cornbread

Senior Member
Appreciate the comments. I'm still concerned that the best practice of insuring a good lock out tag out is "great documentation". Most places I've worked. when we are asked to lock out P1-123 pump , we go to the MCC where P1-123 is fed from and lock it out, we do voltage checks at the bucket making sure we are good, but we rely on the MCC documentation and tagging to be up to date.

I'm toying with a pilot light solution at the motor start PB that would indicate the power to the correct motor was removed. May not be the best solution but I thinks its worth looking at.
 

don_resqcapt19

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Staff member
Location
Illinois
Occupation
retired electrician
Appreciate the comments. I'm still concerned that the best practice of insuring a good lock out tag out is "great documentation". Most places I've worked. when we are asked to lock out P1-123 pump , we go to the MCC where P1-123 is fed from and lock it out, we do voltage checks at the bucket making sure we are good, but we rely on the MCC documentation and tagging to be up to date. ...
The problem with that is I have seen a number of cases where the intent was to lock out P-1-123, but they actually locked out P1-125, and then worked on P1-123. Having a method of proving the correct equipment is locked out at the equipment it critical.
 
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