70E Hazard locations

[Rich Elec.]

I checked 70E Table 130.7 (C)(9) for this question, I didn't see the application, so I would like a second opinion to make sure that I am right.

Fused disconnects and MCC buckets in the off position, so line side is still live, plastic barriers are in place.
Is connecting wire to the load side a hazard category location?
I am thinking that it is not.

Thanks,
Rich

 

[jim dungar]

Is connecting wire to the load side a hazard category location?

Yes its a hazard category location.


Your voltage PPE requirement may be 0V. You may be, and probably are, within the arc flash approach zone for the busing in the MCC vertical section.

There are many cases of tools, screws, and other things rolling between a bucket and the one below it and causing a fault.

 

[Rich Elec.]

Do I understand you correctly, if the PPE requirement is 0 volts, but it is a Hazard category location then no specific PPE would be required?
Do you have a Section number that I could look up?

 

[jim dungar]

Do I understand you correctly, if the PPE requirement is 0 volts, but it is a Hazard category location then no specific PPE would be required?

No, I meant you should be wearing some amount of PPE
There are two major types of PPE: Voltage and Arc Flash.
While the voltage hazard may be 0V, it is probable that you are still within the arc flash approach boundary for the MCC bussing in that vertical section. What is the incident energy at your MCC bussing?

 

[Rich Elec.]

I understand what you mean, voltage PPE and arc flash PPE, and that there is not a voltage hazard but an arc flash hazard.
This gives me a place to start. I will look some more through 70E.
I am interested in what level of arc flash PPE would be required.

Your question is, what is the incident energy at the MCC busing.
Is the answer the AIC rating?

 

[zog]

The incident energy the the heat a person would be exposed to in an arc flash event, measured in calaories per square cm, that is what determines the arc flash PPE you need to wear.

The real question here is why don't you just kill all power in the MCC?

 

[jim dungar]

Your question is, what is the incident energy at the MCC busing.
Is the answer the AIC rating?

No it is not.
Have you had any 70E training?

 

[Rich Elec.]

I have not had any formal 70E training.
It is a step that I will take.
I think that you have given me enough of an answer to my question in the original post. I should be wearing arc rated PPE to connect a load side wire when the line side is live. Can you give me a reference that I can look over, and to present to our safety rep.

Thanks for the help.
Rich

 

[jim dungar]

NFPA70E 130.3(B) says when working within the arc flash protection boundary, as determined in 130.3(A), PPE is required.

 

[zog]

I have not had any formal 70E training.
It is a step that I will take.
I think that you have given me enough of an answer to my question in the original post. I should be wearing arc rated PPE to connect a load side wire when the line side is live. Can you give me a reference that I can look over, and to present to our safety rep.

Thanks for the help.
Rich

I think you are missing the point, the NFPA 70E is not a guide to working on energized equipment, in fact one of the very first statements in the standard requires nealy all work to be done in an electrically safe working condition.

NFPA 70E Article 130.1 Justification for work. Live parts to which an employee might be exposed shall be put into an electrically safe work condition before an employee works on or near them, unless the employer can demonstrate that deenergizing introduces additional or increased hazards or is infeasible due to equipment design or operational limitations.

Energized parts that operate at less than 50 volts to ground are not required to be deenergized if there will be no increased exposure to electrical burns or to explosion due to electric arcs.

NOTE 1: Examples of increased or additional hazards include, but are not limited to, interruption of life support equipment, deactivation of emergency alarm systems, shutdown of hazardous location ventilation equipment

NOTE 2: Examples of work that may be performed on or near exposed energized electrical conductors or circuit parts because of infeasibility due to equipment design or operational limitations include performing diagnostics and testing (e.g., start-up or troubleshooting) of electric circuits that can only be performed with the circuit energized and work on circuits that form an integral part of a continuous process that would otherwise need to be completely shut down in order to permit work on one circuit or piece of equipment.

(Zog's note: If you dont know what "Infeasible" means, look it up; it means "incapable of being done". Dont confuse feasible with convenient.)

70E training is not optional, it is required, that is what you need to be telling your safety rep.

 

[Rich Elec.]

First off let me thank the both of you for your responses.
Zog, I have been reading your "Safety FAQ" portion of the page.

Zog, I see your point, I said that I need to be wearing arc flash ppe when connecting the load side wires. You are pointing out my acceptance for working on live equipment.

I will look into 70E training.
Rich

 

[zog]

Right, hard to justify working live in a MCC. The 70E would require an Enwrgized Electrical Work Permit, I doubt your safety dept would sign off on that. Unless this is some safety related system that cannot be shut down.

 

[sparky=t]

Right, hard to justify working live in a MCC. The 70E would require an Enwrgized Electrical Work Permit, I doubt your safety dept would sign off on that. Unless this is some safety related system that cannot be shut down.

if he had a saftey department he would be trained!?