15KV insulated overhead cable - applying insulation sleeves from grounded platform

[paulengr]

I can not find anything that considers an insulated HV line when talking about approach boundaries.

Is it legal to install HV sleeves into energized 15KV lines from scaffolding with or without rated hot gloves?
I know for uninsulated a EWP would need to be used but does that apply to an insulated line?

Thanks.

It is not high voltage. That is above 40 kV. Only NEC and MSHA (coal) mess this up. Use the internationally accepted definitions (IEEE).

An EWP is not required because this is distribution equipment which follows NESC and OSHA 1910.269. An EWP is a 70E and OSHA Subchapter S concept. Incorrect regulation.

In MV there are bare, covered and shielded cables. Shielded systems work like a Faraday cage. There is nothing exposed. Even if you drove a spike through it (which is actually a procedure for some), the spike bridges the shield and conductor, grounding it and tripping the system. So your use case is very questionable. In mining they use several types of shielded portable cables which often have to be moved either by hand or with mechanized equipment while energized. With or without gloves. It’s not a big deal.

Terminations to bare connections (elbow connectors are safe while attached), bare, or covered cables are all treated as bare conductors. Available work methods are insulated tools, or insulated gloves. Bare hands live line is not very practical...it’s best used at 69 kV and above. And the comment about doing it from scaffold is wrong. You can use an insulated platform but not standard scaffold.

Based on the question though all are not qualified. Unlike Subchapter S, 1910.269 requires everyone involved to be qualified and that includes even tree trimmers for instance. So based on that alone you can’t do what you are attempting.

 

[petersonra]

years ago I was working on some switchgear for a 15 KV genset before the genset was installed. Inside the switchgear some big cables came in from the genset. They looked like giant SO cables to me, about an inch in diameter with a tough rubberish coating.

I noticed some scuff marks on one of the cables. there were several places where the outer insulation was damaged and I could see under the insulation there was some kind of metallic shield. I mentioned the damage to one of the electricians who installed it. he said he would repair it. I figured there was some kind of special repair kit for such things, but when I asked about it he said he was going to wrap the damage with ten turns of a certain 3M tape that was good for 2000 V so ten turns was more than enough for 15 KV. I was unconvinced at the time this was an appropriate repair but let it go assuming the electrician knew more about such things than I.

 

[Hv&Lv]

1910.333(b)(1) | Occupational Safety and Health Administration

www.osha.gov

Application is “exposed” parts.

1910.333(c)(3)(i)
"Unqualified persons."
1910.333(c)(3)(i)(A)
When an unqualified person is working in an elevated position near overhead lines, the location shall be such that the person and the longest conductive object he or she may contact cannot come closer to any unguarded, energized overhead line than the following distances:
1910.333(c)(3)(i)(A)(1)
For voltages to ground 50kV or below - 10 feet (305 cm);
1910.333(c)(3)(i)(A)(2)
For voltages to ground over 50kV - 10 feet (305 cm) plus 4 inches (10 cm) for every 10kV over 50kV.
1910.333(c)(3)(i)(B)
When an unqualified person is working on the ground in the vicinity of overhead lines, the person may not bring any conductive object closer to unguarded, energized overhead lines than the distances given in paragraph (c)(3)(i)(A) of this section.
1910.333(c)(3)(ii)
"Qualified persons." When a qualified person is working in the vicinity of overhead lines, whether in an elevated position or on the ground, the person may not approach or take any conductive object without an approved insulating handle closer to exposed energized parts than shown in Table S-5 unless:
1910.333(c)(3)(ii)(A)
The person is insulated from the energized part (gloves, with sleeves if necessary, rated for the voltage involved are considered to be insulation of the person from the energized part on which work is performed), or
1910.333(c)(3)(ii)(B)
The energized part is insulated both from all other conductive objects at a different potential and from the person, or
1910.333(c)(3)(ii)(C)
The person is insulated from all conductive objects at a potential different from that of the energized part.




This is what I was wanting you to see.

It says an unqualified person can’t get within the minimum distances unless it’s guarded or insulated from damage.

Are you qualified? If so you can guard it and protect it so others can get near it.
If your not qualified, as you aren’t apparently, then you can’t get near it.

 

[K7JLJ]

HV,
Yes, that is why we are putting the sleeves on for the unqualified workers to be to get within 1 ft of the wires.

What qualifications are needed to touch tree cable. A licensed electrician is qualified if he knows the risk involved and has “training” of such.

1910.399
Qualified person. One who has received training in and has demonstrated skills and knowledge in the construction and operation of electric equipment and installations and the hazards involved.

The issue is that I find nothing that says an “unexposed” potential is a risk or requires a qualified person to work on. As mentioned earlier, as "trailing cable" is often handled with bare hands in the mines. They do have a zero flux circuit and ground check though that opens the feeder.

How would it be any different putting a sleeve on an RMC run with 15KV running inside? There is no exposure when applying to an insulated wire either, right?

If there is no exposure it doesn't require an EWP, right?

ALSO: "If your not qualified, as you aren’t apparently, then you can’t get near it." Show me where I'm not qualified please?

 

[K7JLJ]

paulengr,

I came up in 1990 at Barrick Goldstrike handling trailing cable with bare hands, MSHA does mess things up (I knew someone would nail me on HV) and they are nowhere near OSHA. We did things for years that were dangerous as crap and MSHA never cared, company never cared... until our first death and when they defunded MSHA and they had to make their money off of fines.

I've been an Electrician for 30 years and never saw 70E arc flash gear used until my current job of the past 2.5 years.

"Safe" is a relative term. I'm not concerned about it being unsafe. I'm just looking for a code that says what is required.

 

[Hv&Lv]

ALSO: "If your not qualified, as you aren’t apparently, then you can’t get near it." Show me where I'm not qualified please?

“My point of the question is that some of our guys think it’s ok to do this bare handed from a grounded structure. They have no line work experience, I have a few years in a Mine (MSHA) but am no old salt at it.

Common sense says to keep 2 insulation levels between you and MV or HV though.”

“I'm not concerned about it being unsafe.”

I am still considered qualified in line work, and wouldn’t try something as careless as what your guys consider OK. Neither will a lawyer the first time something goes wrong..

just saying...

 

[K7JLJ]

yeah, I hear ya.

I turned them down the first time because to me "safe" is working from an EWP, but NEC does not require one from what I've found nor does it consider it unsafe and I can see them making refusal a "failure to perform your job" issue and sending someone home.

Should a death occur, OSHA might use NESC against them as "industry standard" but I highly doubt it since it does not apply to private owners.

The point of the question is not to get "ammo" to refuse the work, it's to find a standard that applies as a private owner to use gloves, ewp, etc. OR NOT so that a Reliable Method for the job can be made to provide a safe consistent method for all to follow.

 

[Hv&Lv]

yeah, I hear ya.

I turned them down the first time because to me "safe" is working from an EWP, but NEC does not require one from what I've found nor does it consider it unsafe and I can see them making refusal a "failure to perform your job" issue and sending someone home.

Should a death occur, OSHA might use NESC against them as "industry standard" but I highly doubt it since it does not apply to private owners.

The point of the question is not to get "ammo" to refuse the work, it's to find a standard that applies as a private owner to use gloves, ewp, etc. OR NOT so that a Reliable Method for the job can be made to provide a safe consistent method for all to follow.

The nec isn’t going to tell you how to do the job safely.
That’s OSHA and 70E

 

[K7JLJ]

The nec isn’t going to tell you how to do the job safely.
That’s OSHA and 70E

Seems they are not in this case either.

 

[paulengr]

Let’s break this down a little more simple. Why not just use yellow caution tape?

If riggers are working around steel cables, ropes, or other hanging lines they often flag it with strips of yellow caution tape. Similarly when a janitorial crew moos a floor they put up caution barricades or cones or signs. If they mop the floor in an electrical room they aren’t opening cabinets and they do the same thing. Although folks can be pretty bad and cranes can do serious damage experience has shown that once someone recognizes the hazard it is very easy to avoid.

Line hose is used in live work on bare or covered (not insulated) lines where line workers cannot de-energize other phases where they are working. It is there to avoid accidents brushing up against it. This is for energized work or de-energized work with energized lines present. I have never used it in a 1910.333 situation and I can’t see a need for it.

So what you are doing is using an energized work tool and methods on an insulated line instead of the right tool (caution tape) leading to confusion both on your part and others attempting to respond.

 

[K7JLJ]

well put, something that nobody picked up on is that the scaffolding that we are standing on was put up BEFORE the sleeves were added.

They put it up, we add sleeves, then take them off and they remove scaffolding!

Ya can’t make this stuff up!

If it’s insulated and has no approach boundary, yellow tape is perfect.

If it’s not and requires sleeves then there should be a method of applying them that constitutes a qualified method and it should be in a regulation somewhere.

So let’s break down the answers so far...

Insulated & shielded wire is considered “live” under NESC and is treated as such.

Under OSHA / NEC there is no addressing the situation of lines that are insulated or at least no one has quoted where it is.

The safe thing is to handle it it like it’s leaking and use PPE, Unless you come from the mines and are use to handling 7200vac trailing cable bare handed.

op

 

[K7JLJ]

I wanted to add, I appreciate all the input and will be using the NESC quote to make an argument for “best practice” and that allowing scaffolders to access the wire inside of 10ft (treating as energized and exposed) would be best, unless they can show some sorry of training (scaffolding crews) that considers them qualified to approach. If they can, then I suggest they put on the sleeves as they build up to the wires.

Thanks again folks.

 

[wbdvt]

I would refer you to OSHA 1910.269 which is the section for Electric Power Generation, Transmission and Distribution. There is a note in the beginning of this reg that states it is also applicable to installations in industrial facilities that are similar to utilities. This installation falls under this section.

So, you would have to meet all the requirements in this reg to work on or near that line. This includes the requirement for an arc flash assessment that was required by March 2015 as well as job briefing, work methods, etc.

You need to review, understand and comply with OSHA 1910.269 for any work on this line or other parts of your facility that falls under this reg.

 

[K7JLJ]

Thanks wbdvt,

More digging lead me to:

• 1910.332(b)(3)(ii)The skills and techniques necessary to determine the nominal voltage of exposed live parts, and
• 1910.332(b)(3)(iii)The clearance distances specified in 1910.333(c) and the corresponding voltages to which the qualified person will be exposed.
  • Note 2: Qualified persons whose work on energized equipment involves either direct contact or contact by means of tools or materials must also have the training needed to meet 1910.333(C)(2).
    • 1910.333(c)(2)(2))"Work on energized equipment." Only qualified persons may work on electric circuit parts or equipment that have not been deenergized under the procedures of paragraph (b) of this section. Such persons shall be capable of working safely on energized circuits and shall be familiar with the proper use of special precautionary techniques, personal protective equipment, insulating and shielding materials, and insulated tools.
    • 1910.333(c)(3)"Overhead lines." if work is to be performed near overhead lines, the lines shall be deenergized and grounded, or other protective measures shall be provided before work is started. If the lines are to be deenergized, arrangements shall be made with the person or organization that operates or controls the electric circuits involved to deenergize and ground them. If protective measures, such as guarding, isolating, or insulating, are provided, these precautions shall prevent employees from contacting such lines directly with any part of their body or indirectly through conductive materials, tools, or equipment.
    • Note: The work practices used by qualified persons installing insulating devices on overhead power transmission or distribution lines are covered by 1910.269 of this Part, not by 1910.332 through 1910.335 of this Part. Under paragraph (c)(2) of this section, unqualified persons are prohibited from performing this type of work.
  • 1910.269(a)(2)(ii)(C)(2)(ii)(C))The minimum approach distances specified in this section corresponding to the voltages to which the qualified employee will be exposed and the skills and techniques necessary to maintain those distances,
  • Table R-6—Alternative Minimum Approach Distances for Voltages of 72.5 kV and Less1
    • 5-15KV = 2.14ft
  • 1910.269(q)(3)(xiv)The employer shall ensure that employees maintain the minimum approach distances, established by the employer under paragraph (l)(3)(i) of this section, from all grounded objects and from lines and equipment at a potential different from that to which the live-line barehand equipment is bonded, unless insulating guards cover such grounded objects and other lines and equipment.
  • 1910.269(x))
    • Minimum approach distance. The closest distance an employee may approach an energized or a grounded object.

 

[jim dungar]

MV-105 is shielded, does that somehow make it “protected and not considered live” for working on?

Are these cables supported on insulators? If so, then someone thought they needed clearance.

A case can be made that these shielded conductors are not 'exposed energized parts' and do not require clearance because they are allowed to be in intimate contact with grounded surfaces such as enclosures and metallic raceway. However they are definitely still energized and therefore 'live'. I have seen several Electrical Safe Work Practices procedures which prohibit touching or moving energized conductors unless they are flexible and intended to be moved while energized, such as flexible cables.

 

[K7JLJ]

Then you would be making the argument that there is no potential and this no need for qualification of persons doing work.

Round and round it goes.

1910.333(C)(3) say overhead lines that are energized. Not exposed or uninsulated.

 

[jim dungar]

Most of NFPA 70E appears to be purposely vague.This is why NFPA 70E requires you to perform a risk assessment as well as a hazard assessment when deciding on how and if a task should be performed.

 

[wbdvt]

Since this is on 15kV class energized power cable, NFPA 70E, NEC, and OSHA 1910 Subpart S does not apply here. OSHA 1910.269 and NESC would be the applicable standards and regulations to be reviewed and followed. OSHA 1910.269(c) requires a job briefing be done and it lists specific subjects to be covered so this may be a little different than an EWP.

The NESC also states that unless an incident energy analysis has been done, then the arc rated clothing system needs to be a 4 cal, 8 cal or 12 cal system and that depends on fault current and clearing time. What cal system was used by the employees installing the rubber sleeves?

There seems to be a mixing of standards here but in this situation where there is a 15kV class insulated overhead line, it is clear the standards/regulations that apply are OSHA 1910.269 and the NESC and all work methods, job briefings, employee qualifications, etc. must follow these documents.

For everyone's safety, the proper standards and regulations need to be identified and followed. In the event of an incident, during an investigation that is what will be asked and if the proper standards were not being followed, that will be food for fodder for a lawyer.