PPE for terminating wires on energized Circuit Breaker

[iwire]

if the line terminals are not accessible, how is there any danger to the employee?

True, but the line terminals are almost always exposed when the load side terminals are.

 

[iwire]

You can not turn off a fused disconnect and check continuity of fuses or replace fuses either - the supply terminals are still live.

That falls under troubleshooting and can be done with PPE.

 

[hillbilly1]

Hillbilly

Can you point out the OSHA section that allows us to add a circuit to a panel with exposed live parts?

It is my understanding that live work is prohibited in most cases even with PPE.

I think it is mostly written for lawyers, easy to win a case if something out of the ordinary happens. Safety is just a byproduct and not the prime objective. They can come back with "You did it for more proffit, instead of protecting your employees. If it was enforced to the letter of the law, our economy would go down the tank in a hurry. There's responsible, then there's stupid.

 

[kwired]

That falls under troubleshooting and can be done with PPE.

So we are allowed to troubleshoot with use of PPE but to terminate load conductors with the line side energized is a not allowed even with use of PPE. I understand the intentions of these rules but they need some work.

 

[ron]

ABB and other beginning to bring over IEC designed panelboards are trying to advertise touchsafe panels allowing you to do more energized, but I am in agreement with Bob, that you are still exposed.

 

[iwire]

So we are allowed to troubleshoot with use of PPE but to terminate load conductors with the line side energized is a not allowed even with use of PPE.

That is my understanding unless shutting down creates more of a hazard.

Now many people are quick to evoke that but IMO you need to consider how you would justify that choice in court if something goes wrong.

I understand the intentions of these rules but they need some work.

IMO the work that needs to be done is to tighten the restrictions up. Like removing the part about 'illumination for an area'

There is no reason that workers should be put at risk just to save money.

 

[kwired]

That is my understanding unless shutting down creates more of a hazard.

Now many people are quick to evoke that but IMO you need to consider how you would justify that choice in court if something goes wrong.




IMO the work that needs to be done is to tighten the restrictions up. Like removing the part about 'illumination for an area'

There is no reason that workers should be put at risk just to save money.

I don't disagree about the safety aspect, anything energized poses risks that are not there when not energized, no matter if you are maintaining or installing. There are hazardous tasks in many jobs, there are ways of minimizing the hazards in most cases, they come with a cost, but so does not using safety standards and equipment. The only real winners when there is a problem is the attorneys.

Statistically I still have a better chance of being killed on the way to the job than I have while working in an panel where the only thing energized and exposed is the supply terminals.

I don't know where I am going with this - just venting I guess.

 

[petersonra]

I note that no one actually asnwered the question I asked.

The OSHA requirement is to not expose employees to live electrical parts. If one were to have a guard that prevented exposure to the line side terminals, how would there be any exposure? I am not arguing that in this particular case there is not exposure since it would appear there is, and thus anyone within the space would need appropriate PPE. I am not even going to argue that "finger safe" is adequate protection.

Just that If there was no exposure to live voltage, how would the OSHA clause even be triggered?

 

[kwired]

I note that no one actually asnwered the question I asked.

The OSHA requirement is to not expose employees to live electrical parts. If one were to have a guard that prevented exposure to the line side terminals, how would there be any exposure? I am not arguing that in this particular case there is not exposure since it would appear there is, and thus anyone within the space would need appropriate PPE. I am not even going to argue that "finger safe" is adequate protection.

Just that If there was no exposure to live voltage, how would the OSHA clause even be triggered?

I feel I touched on this back in post 16 with the covers required in Canadian code over the supply conductors entering a panelboard. The examples I have seen involved Square D circuit breaker panels, the Canada version is same panelboards sold in the US but have a metal cover over the entire area and including the line side lugs of the main breaker, this being an additional cover to the typical dead front cover that goes over the entire face of the cabinet. If you remove the main cover you are not exposed to any energized components as long as the main is open. "Finger safe" covers still allow access to energized parts with a probe or similar object.

 

[iwire]

I feel I touched on this back in post 16 with the covers required in Canadian code over the supply conductors entering a panelboard.

I thought so.


I also thought it was pretty obvious the OSHA rules only apply to exposed live parts.

 

[zog]

I have also wondered how long until our inspectors can no longer remove a panel cover to inspect if the panel is energized?

I understand that all employed persons are subject to these rules but the inspectors technically being State employees I am a little surprised that they still inspect things that are energized. Someday that will probably stop and will create hardships for everyone involved. Many projects are already in use before final inspection happens, scheduling shutdown for inspection will really be hard to adjust to dealing with, let alone the fact there is so much work still done that should have shutdowns just to perform the work. Many disable circuit they are working on, but there is still a lot of work still done everywhere in panels that are energized.

Have you read the 2012 70E? Inspections and electrical inspectors were specifically added to the text so yes your inspectors have to comply with the 70E requirements. Now, if you read the standard you will find that there is no need to schedule a shut down for a visual inspection, that is not "Energized work", your inspectors just have to wear the proper PPE to do so.

 

[zog]

I note that no one actually asnwered the question I asked.

The OSHA requirement is to not expose employees to live electrical parts. If one were to have a guard that prevented exposure to the line side terminals, how would there be any exposure? I am not arguing that in this particular case there is not exposure since it would appear there is, and thus anyone within the space would need appropriate PPE. I am not even going to argue that "finger safe" is adequate protection.

Just that If there was no exposure to live voltage, how would the OSHA clause even be triggered?

Finger safe, or gaurded is not the same as arc rated, this is clearly defined in the 70E definitions. While gaurding the line side removes the shock hazard it does little for the arc flash hazard so if the work on the de-energized part of the enclosure is withing the arc flash boundary of the energized line side PPE would still be required for arc flash protection.

 

[petersonra]

Finger safe, or gaurded is not the same as arc rated, this is clearly defined in the 70E definitions. While gaurding the line side removes the shock hazard it does little for the arc flash hazard so if the work on the de-energized part of the enclosure is withing the arc flash boundary of the energized line side PPE would still be required for arc flash protection.

so if someone walks in front of a closed cabinet that is HRC4 they have to have a space suit on?

 

[zog]

so if someone walks in front of a closed cabinet that is HRC4 they have to have a space suit on?

No, they are not interacting with the equipment. That would just be silly.

 

[petersonra]

No, they are not interacting with the equipment. That would just be silly.

Where does 70E say anything about arc flash being about interacting with the equipment. I seem to recall it says something about being exposed to live voltage.

If there is no live voltage, how is there any exposure to an arc flash?

 

[mayanees]

2102 70E

2102 70E

Interacting is included in the 2012 70E edition, 90.2 Scope:
This standard addresses electrical safety-related work practices for employee workplaces that are necessary for the practical safeguarding of employees relative to the hazards associated with electrical energy during activities such as the installation, inspection, operation, maintenance, and demolition of electric conductors, electric equipment, signaling and communications conductors and equipment, and raceways.
John M

 

[petersonra]

Interacting is included in the 2012 70E edition, 90.2 Scope:
This standard addresses electrical safety-related work practices for employee workplaces that are necessary for the practical safeguarding of employees relative to the hazards associated with electrical energy during activities such as the installation, inspection, operation, maintenance, and demolition of electric conductors, electric equipment, signaling and communications conductors and equipment, and raceways.
John M

The point I was trying to make was that the PPE requirements are triggered by specific situations. While I not gotten around to reading the 2012 NFPA70E yet, I don't recall that in the previous edition that merely interacting with equipment triggered PPE requirements. It seemed to me that exposure to live voltages over 50V did, along with some specific tasks.

 

[petersonra]

Have you read the 2012 70E? Inspections and electrical inspectors were specifically added to the text so yes your inspectors have to comply with the 70E requirements. Now, if you read the standard you will find that there is no need to schedule a shut down for a visual inspection, that is not "Energized work", your inspectors just have to wear the proper PPE to do so.

unless you use binoculars for the visual inspection.

 

[zog]

Where does 70E say anything about arc flash being about interacting with the equipment. I seem to recall it says something about being exposed to live voltage.

If there is no live voltage, how is there any exposure to an arc flash?

Since the 2009 version, see article 100 - Definitions.

Arc Flash Hazard. A dangerous condition associated with the possible release of energy caused by an electric arc.

Informational Note No. 1: An arc flash hazard may exist when energized electrical conductors or circuit parts are exposed or when they are within equipment in a guarded or enclosed condition, provided a person is interacting with the equipment in such a manner that could cause an electric arc.

 

[petersonra]

Since the 2009 version, see article 100 - Definitions.

Arc Flash Hazard. A dangerous condition associated with the possible release of energy caused by an electric arc.

Informational Note No. 1: An arc flash hazard may exist when energized electrical conductors or circuit parts are exposed or when they are within equipment in a guarded or enclosed condition, provided a person is interacting with the equipment in such a manner that could cause an electric arc.

again I ask the same question. how do you create an arc if there is no exposure to live parts?