NFPA 70E questions

[cornbread]

I had the follwoing questions asked reciently and I would like to solicite other opinions.

1. If I can plug in a drill with out wearing voltage gloves, why do I have to wear voltage rated gloves if I use a meter to measure the outlet?

My answer, I hope some what correct :the plug is specifically designed for the purpose, the meter while designed to read voltage is not specifically designed for use in a outlet.

2. If the insulation on wiring is sufficiet to protect me from a shock hazard...then why do I have to use voltage gloves if I use a insulated tools?

My answer, using any tool / meter that makes contact with a live part is the same as touching the live part and voltage rated gloves are the best "tested" protection against the shock hazard. How do you know your insulated tools are in proper working condition...do you test your tools on a regular basis...gloves should be tested at 6 months intervals and inspected prior to each use.

Again I hope my answers are not too far off base. As always your comments are greatly appreciated.

 

[chris kennedy]

zog,..zog...

Testing of energized electrical conductors and circuit parts is covered in T130.7(C)(9). Yes IMO you are correct.

Insertion of a cord body into a receptacle is not covered.

 

[zog]

I had the follwoing questions asked reciently and I would like to solicite other opinions.

1. If I can plug in a drill with out wearing voltage gloves, why do I have to wear voltage rated gloves if I use a meter to measure the outlet?

My answer, I hope some what correct :the plug is specifically designed for the purpose, the meter while designed to read voltage is not specifically designed for use in a outlet.

Who says you do? The RAB for 120V is "Avoid contact", IMO you can safely avoid contact putting probes into an outlet.

2. If the insulation on wiring is sufficiet to protect me from a shock hazard...then why do I have to use voltage gloves if I use a insulated tools?

My answer, using any tool / meter that makes contact with a live part is the same as touching the live part and voltage rated gloves are the best "tested" protection against the shock hazard. How do you know your insulated tools are in proper working condition...do you test your tools on a regular basis...gloves should be tested at 6 months intervals and inspected prior to each use.

You need to wear gloves if your hands cross the RAB or any un-insulated object you are holding crosses the RAB. Insulated tools have to be rated for the voltages you are working on and have a means of verifing the insulation condition, in most cases that mean 2 layers of insulation, different colors, if you can see the color underneath (Usually yellow) your tool should be replaced. Tape on a tool does not make it an "insulated tool".

 

[cornbread]

I could be wrong and I hope I am, but when i look at the definition of working on Energized electrcial circuits... NFPA70E Article 100.

Working on energized circuit: Coming in contact with energized..circuits parts with hands, feet or orther body parts, with tools, probes, or test equipment, regardless of the PPE....

If I consider voltage testing working on energized circuits...form table 130.7 (C)(9) I see a hazard/risk of 1 and rubber insulating gloves.

If this is incorrect please let me know.. we are trying to hash out what PPE we need for our 120vac circuits.

 

[billsnuff]

I agree with you cornbread......<240 volts, voltage testing Table 130.7(C)(9).

I guess there has not been an Arc Flash Study conducted????

If there has been a study done, what does the label say the HRC is ???

If there has been a study done and labels applied to equipment, ignore the table.

I have had the study conducted, a lot of my equipment is HRC 0, see 130.7(C)(10). Untreated natural fibre shirt (LS) and pants, leather gloves, safety glasses and hearing protection.

 

[cornbread]

No arc flash is study is needed in most of my 120Vac cases as the majority of the equipment is fed with a 30KVA transformer. My concern is only the shock hazard. Our electricians have no problems using the voltage gloves when working on energized circuits, I'm getting flack from our instrument, analyzer and controls groups.

 

[billsnuff]

Approach boundaries Table 130.2(C)

What kind of resistance, from those three groups, are you getting in particular?

What types of tasks are they to perform?

Will using Annes F page 76 and 77 be of any help ?

I believe that if you reduce routine tasks to writing for qualified personnel, conduct training for that task, then you can bypass the energized work permit for that task, but will need annual review. Someone please correct me if i am off base here.

 

[cornbread]

Resistance to using insulated gloves. A typical task, I-shop troubleshooting a 120v soleniod valve (using a meter to see if it is energized). Same type of task for the control and analyzer group, checking inputs / outputs on a PLC or DCS system. They have the misguided notion that 120vac is not dangerous. Being old school myself I use to perform the same duties with out any PPE. I personally don't see much of a problem issuing low voltage gloves and asking our guys to start using them. To hear them talk I just added 4 hrs of work per job. Its the old culture change.

On a side note we are in the process of writing procedures for routine task to help reduce the amount of paper work (hot work permits) to a minimum.

Another side note, we had our monthly safety meeting this week and the question came up on how many "energized work permits" and how difficult were they to obtain? 4 jobs had a hot work permit started and when we got down to getting management to sign off...well all 4 jobs were schedule so the power could be shut off. It's painfull at first but it seems to be getting better.

 

[billsnuff]

one of the biggest problems i have with 70E is keeping shock and arc flash hazards seperate. 130.2 (C) Table.

since i have had the study done i ignore table 1307(C)(9).

while you have a task that is HRC1, for me it is HRC0 and leather gloves are optional. AN Note 2 Table 130.7(C)(10).

Also, check 130.3(A)(1) last sentence, may be justification for the study.

As for people issues, it is treated as LOTO. Depending on the level of the hazard, the punishment fits the crime, up to and including discharge.

I treat my folks like adults. The expectations are clear, we develope plans together. We designed it, we own it, we have to live up to it, end of story. Safety has to be the first item in job performance.

My 54 chevy didn't have air bags or seat belts, but my 98 buick does. improvements in safety.

If I had someone who wouldn't keep himself safe, I have to deal with him, but if he endangers another, he'll be looking for work, and I'll sleep just fine.

You might try this book: http://www.amazon.com/Employees-Dont-Theyre-Supposed-About/dp/0071342559

 

[WDGILBERT]

Table 130.7(CV)(10) lists the minimum required PPE for arc flash protection. It does not cover exposure to live parts. This is covered in section 130.2(C). My interpretation of this is that if any part of your body or any uninsulated object in your hand is closer than the Restricted Approach Boundary to an exposed energized part, then you must wear the appropriate voltage rated gloves. It would appear from reading this that putting insulated voltage probes in a receptacle would not require gloves. Leather gloves are used to protect against arc flash and to protect the rubber voltage rated gloves, never to protect against exposure to voltage.

 

[cornbread]

I could be wrong and I hope I am, but when i look at the definition of working on Energized electrcial circuits... NFPA70E Article 100.

Working on energized circuit: Coming in contact with energized..circuits parts with hands, feet or orther body parts, with tools, probes, or test equipment, regardless of the PPE....

If I consider voltage testing working on energized circuits...form table 130.7 (C)(9) I see a hazard/risk of 1 and rubber insulating gloves.

 

[billsnuff]

I gave an example of a panel < 240 vac.

while you have a task that is HRC1, for me it is HRC0 and leather gloves are optional. AN Note 2 Table 130.7(C)(10).

Since I have had a study completed, the panel has a label for HRC 0, based on the study, therefore I ignore 130.7(C)(9). The shock hazards however, have not changed 130.2 (C). PPE required per col 3 distance.

non-melting or untreated natural fibre LS Shirt Long pants, safety glasses,
leather gloves (as needed), think Prohibited Approach, i.e. avoid contact.

if I have a meter (cat 3 or 4) with VR Probes and safety stops for the fingers,
i believe that i am good to go. minimum, perhaps, but ok. anyway thats how i read it.

 

[pfalcon]

Remember that 70E is written to fit all sizes. If you are probing something then presumably something is wrong/broken. When it goes catastrophic you don't have time to get the PPE you were supposed to be wearing. Catastrophic happens when you think a routine job is under control and predictable - and then it isn't.