Utility Safety Q & A Articles

Q: Why do some experts say ground rods won’t work to trip a circuit?

A: The experts say this because they are right depending on the conditions, which we’ll soon discuss. But let’s start with a definition of the idea of “remote ground” as the point at which we connect a protective system to earth. The lower the resistance of that remote ground connection to earth, the more current flows and the faster a fault clears. So, what we should be doing as a rule is using the best available ground to remote earth. The problem is that we often overlook a key element in this debate, which is that the ground source is not what protects the worker. The ground path trips the circuit. Bonding the worker into the ground scheme – the path between the fault and ground – is what provides reliable protection for workers using personal protective grounds. For example, if you ground to a system neutral, you have connected to a very low-resistance path, but you also are connecting to a current-carrying conductor. If workers are not bonded into the ground scheme, they can be exposed to current from the neutral that can result in voltage rises across the ground scheme, especially if a fault current rises on the neutral from some remote event on the system. If you are on a delta primary system at a transformer bank, that neutral on the secondary side is derived from the ground rod at the foot of the pole. Nobody would take their truck ground up to the neutral bushing of a 300-kVA 277/480 bank, but that’s no different than connecting to the ground rod bonding that 480-VAC neutral to earth. That is why delta system workers use ground rods, and to good effect if the conditions are right.

Q: We don’t provide self-rescue equipment for lone workers, but we recently heard that OSHA is requiring self-rescue equipment as part of the General Duty Clause. Are you familiar with this?

A: This is a complex question, part of which might border on legal arguments. Incident Prevention relates legal opinions to our readers from case outcomes that we are familiar with, but in practice avoids rendering advice or opinions that may border on legal terms.

The rescue requirements in the OSHA rules do not address self-rescue. Many employers address self-rescue in part based on their interpretation of the training requirements found in OSHA 29 CFR 1910.269(a)(2)(i)(B) because of the language that states, “… including applicable emergency procedures (such as pole-top and manhole rescue), that are not specifically addressed by this section but that are related to his or her work and are necessary for his or her safety.” However, the OSHA rules regarding rescue are crew-based rescue requirements and similar to those found in most provincial Canadian health and safety standards. OSHA has several rules regarding lone workers, but those references lack any requirements for self-rescue. It certainly could be that such language would be hard to address considering the numerous instances and types of work in which workers are alone across all industries.

Q: We have a crew performing pole change-outs with the line energized. They are suspending phases with a link stick and digger derrick to provide more clearance between phases to install new poles and hardware. The question is, can the operator leave the controls with the phase lifted? We thought they could, but it seems there has been a change to OSHA 29 CFR 1926.1417(e).

A: The good news is that you cited the wrong rule. Pole change-outs fall under the 1910.269 operation and maintenance rules. You cited the rule for construction (OSHA 1926). The operation and maintenance rule – found at 1910.269(p)(1)(iv) – states the following: “The operator of an electric line truck may not leave his or her position at the controls while a load is suspended, unless the employer can demonstrate that no employee (including the operator) is endangered.”

Of course, it’s not as simple as that. The likely intent of both the operation and maintenance rule and the construction rule is to give an operator a break from the seat for inclement weather exposure or water or bathroom breaks. The issue with the construction rule is that the lift must meet “all of the following,” which are these requirements: no other duties for the operator, the operator stays next to the lift equipment, the equipment is stabilized and locked down, and barricades block the fall zone. Those requirements reflect the Cranes and Derricks in Construction standard (1926.1417(e)). The only requirement with the operation and maintenance rule is assuring no one is at risk.

Q: I read what was written about an air gap for worker protection in the June-July 2020 issue of Incident Prevention magazine, but one of our engineers who sits on a National Electrical Safety Code advisory committee brought something to my attention. NESC C2-2017 444.2 states,  “Air gaps created (e.g., cut or open jumpers) for de-energizing equipment or lines for the purpose of protecting employees shall be tagged and meet minimum clearances as specified in Table 444-1 or separated by a properly rated insulator.” What are your thoughts on this matter?

A: Thanks for your question. Our thought is that your colleague is right regarding the table and we missed it.

To remind iP’s readers, in the June-July 2020 Q&A, we addressed what constitutes an air gap and stated that some utilities build their gap rules around minimum approach distance. We pointed out that MAD is a combination of minimum air insulation distance (MAID) and unexpected movement, which is 24 inches for distribution. We gave the example of a dropout switch that has an 8- or 10-inch-plus gap being acceptable where the MAID in a 15-kV distribution exposure is fewer than 2 inches for phase to ground. We could have worded it better, so we hope we didn’t give anyone the idea that MAID is all that’s necessary. In any case, we don’t want anyone to be misled by what we publish. 

Q: Should we worry about beards in relation to arc flash? At our company, we think hair generally protects the body against extremes. Do you know of any evidence to the contrary?

A: Here is what we know: Human hair is protein fiber. It will burn when exposed to a flame but stop burning when the heat source is removed. Human hair does not melt; it becomes a fragile ash that turns to powder when crushed. This property is known as self-extinguishing. Hair is pretty much like cotton – it burns away. As such, it is not a hazard related to arc flash and actually provides some protection. OSHA does not address exposed hair any differently than the exposed body. It is up to the employer to decide if exposed hair increases employee risk as it pertains to arc flash hazards. If you were to analyze it from a practical perspective, you likely would agree with most of the safety experts we asked about it; they indicated that hair has a heat-insulating property and will not increase a burn hazard to the face provided workers abide by the appropriate arc flash standards of protection established by OSHA. However, there is an issue with some grooming products that may change the hair’s natural resistance to burning, which could be a problem for those lineworkers who use them.

Q: Recently we had an employee reference OSHA 29 CFR 1926.960(f) and 1910.269(l)(7), “Conductive articles.” The question is, can an employee work in an energized area while wearing jewelry, and earrings in particular? The rules discuss conductive articles such as watches, bands, rings and chains, but I do not see where it mentions earrings. 

A: When it comes to interpretation, it is good to confine a rule to the language used, but sometimes you also have to address the intent. The concern that drove the creation of this rule was whether jewelry, which is conductive, increases electrical contact risk. Those risks are twofold: (1) Does the jewelry make an electrical shock more likely, and (2) does the jewelry increase the damage or level of injury from an electrical contact? This rule does not fit well in the utility industry because its origin is the indoor electrical industry. Electricians rarely employ rubber gloves and were sticking their bare hands in energized panels in close quarters. Still, we can’t ignore the rule, but we can easily address it. As far as electric utilities are concerned, hands in close quarters to uncover bus or wire could cause a flash where jewelry goes to ground. You would get shocked anyway, but the jewelry could cause an arc flash, which increases injury levels with burned skin. That doesn’t really apply where we work unless your uncovered hands are in a meter can. The answer for either 1926 Subpart V or 1910.269 is in the wording of the rule, so look closely: “When an employee performs work within reaching distance of exposed energized parts of equipment, the employer shall ensure that the employee removes or renders nonconductive all exposed conductive articles, such as keychains or watch chains, rings, or wrist watches or bands, unless such articles do not increase the hazards associated with contact with the energized parts.”

Q: Where does OSHA’s switching and lockout/tagout policy draw the distinction between generating plants and the plants’ substations, particularly with metal-clad substations?

A: It depends more on the equipment used than a distinct line, and it has to do with OSHA’s intent, equipment design and practicality. Let’s look at this from the perspective of intent. OSHA intends that employers have an energy control plan that protects workers. LOTO was developed for that and has worked very well over the years. The data shows that LOTO has been directly responsible for a dramatic decline in severe and fatal incidents related to hazardous energy releases. The utility industry was ahead of OSHA with switching policies and procedures, and OSHA recognizes the effectiveness of that history.

Q: As a contractor doing transmission maintenance, we see many different constructions of statics at the tops of transmission poles and structures. They’re grounded, and we always thought they were safe to handle with leather gloves. Now we’re hearing that statics should be grounded temporarily for worker protection. What’s the explanation for that?

A: It’s called a “static,” but don’t forget that the voltage and current flowing on it is induction-coupled alternating current that will kill you. As an industry, there are a lot of utilities that have worked statics in leather gloves and have had no issues. There are others that had no issues for decades – right up until the day someone on their crew was injured by current on a static.

It’s not actually grounding that protects the worker; it’s bonding of the grounded static. Because of the hazard level associated with this discussion, we need to post a disclaimer here: Incident Prevention magazine publishes what it believes to be the best, most accurate advice available from industry experts, but the publication is not a training venue nor is it in the consulting business. It is the employer who is solely responsible for work methods employed in the field.

Q: Are utilities required to have a written fall protection program that follows a written hazard analysis?

A: It’s not a bad idea because the process assures a fairly complete assessment of fall risks that makes training and protection of workers more effective. We know the source of your confusion because it’s a question we get often, and we’ve looked into it. It takes some deciphering, but here is how the confusion starts. We often hear of power and telcom companies reading OSHA 29 CFR 1910 Subpart D, “Walking-Working Surfaces”; seeing 1910.28, “Duty to have fall protection and falling object protection”; and begin writing complex compliance programs following the Walking-Working Surfaces rule. There is nothing wrong with a robust hazard analysis program that drives training, but if you are doing it to comply with a standard, you may not need to. If you read closely, you will find an exception for both telcom (see 1910.28(a)(2)(vi)) and electric power transmission and distribution (see 1910.28(a)(2)(vii)). The T&D exception relies on compliance with 1910.269(g)(2)(i).

Q: What is considered a forklift? We use wheel loaders equipped with accessory forks on our rights-of-way to unload and move poles and pole sections. We were told by our client’s safety inspector that the loader operators have to be certified as forklift operators because the loaders are equipped with forks. We have always used loaders and loader operators and never had an issue. Where do I find the information to resolve this issue?

A: OSHA refers to forklifts as powered industrial trucks or PITs, while the industry commonly calls them forklifts. OSHA’s construction standard has a section on material-handling equipment. The very last rule is 1926.602(d), “Powered industrial truck operator training.” The rule consists of a single note that states, “The requirements applicable to construction work under this paragraph are identical to those set forth at §1910.178(l) of this chapter.”

I have had people tell me that this rule means that operators of construction equipment using forks, like a loader, are required to be licensed or certified as a PIT operator. That is not the case. The PIT standard that contains forklift operation and training rules is found in the general industry rules. The second sentence of paragraph 1910.178(a)(1) states the following: “This section does not apply to compressed air or nonflammable compressed gas-operated industrial trucks, nor to farm vehicles, nor to vehicles intended primarily for earth moving or over-the-road hauling.” Wheel loaders are designed to move earth. They are not PITs even if they are equipped with forks.

Q: We experienced an event that has caused some confusion among crew and supervisors about what we thought we knew about grounding. We were working midspan on a de-energized 345-kV circuit. We drove a ground rod, grounded our trucks to it and grounded the phases to it. Almost immediately, we smelled hot rubber, and then tires started to smoke. Can you help us understand why this happened?

A: That was likely much more serious than hot tires. For the benefit of readers, we spoke with you on the phone, got details and shared opinions. Here is what happened: Your crew was in a right-of-way with very high induction. The ground rod you drove was very high resistance. When you connected your trucks, essentially you made a radial connection from phase to truck through the ground rod connection. In doing so, you loaded very high induction current onto the truck, which passed into the earth across the tires and outriggers. Many utilities by procedure use ground rods at midspans, and often it goes without problems. This is why we stress learning the principles of current flow in grounded systems. If you can ground phases to the very low-resistance static, the induction load is handled without much risk to workers on the ground. If you do have to ground your truck, and there is high induction, a well-driven rod isolated from the phase grounds might be a good choice. If grounding to the same ground electrode as the phases can energize the truck, as happened in your case, dangerous gradients can occur around the truck, and touch potentials between earth and truck can be deadly.

Q: OSHA’s digger derrick exception – found at 29 CFR 1926.1400(c)(4) – includes digger derricks when they are used for augering holes for poles carrying electric or telecommunication lines, for placing and removing the poles, and for handling associated materials for installation on, or removal from, the poles, or when used for any other work subject to 1926 Subpart V. Substations are included in Subpart V, so why do some people say setting steel or regulators is not covered by the exception?

A: You might try to justify substations as being in Subpart V – except for what the substation rules cover in Subpart V. OSHA 1926.966, “Substations,” is not about construction of substations. It is about working in substations. The rule covers minimum approach distances, guarding of live parts, switching and electrical safety. Steel erection, just like concrete work, falls under horizontal standards. 

The logical thinking of very reasonable people regarding this issue often is challenged for sensibility, mostly because of their perspective. For instance, if I can hang a capacitor on a wood pole with a digger derrick, why can’t I hang a beam and capacitor in a substation with a digger derrick? It’s the same thing, it’s a capacitor. The right perspective is that all construction-related lifting of loads by cranes is regulated under 1926.1400, except lifting poles and pole-mounted equipment that are installed using a truck specifically designed for digging and setting poles. 

Q: We have crews working under a clearance on a de-energized circuit jointly controlled by two different utilities (employers). The concern is that the other employer’s personnel, wishing to bundle maintenance opportunities during the outage, are taking protective relays out of service on their end of the circuit. If a switch were inadvertently closed on their end, taking their relays out means no tripping protection since the other end of the circuit is open, too. Such an action could delay if not eliminate relay protection and raise current on the grounds protecting our workers. Is there an obligation between utilities to manage an outage under common rules?

A: There is an OSHA-based solution that comes in two parts. And even though your question is about grounding and tripping during inadvertent re-energizing, the solution to the issue actually lies ahead of grounding.

As you are aware, OSHA 29 CFR 1910.269(m) contains the rules for de-energizing lines and equipment for the protection of employees. That rule section is the pre-eminent means of ensuring no switch is ever closed without the permission of the employee in charge of the equipment or lines that have been de-energized and placed under their control. As you noted in your inquiry, we ground a circuit after the clearance process to ensure against any possibility of re-energizing. The grounding is based on an evaluation of relay trip settings to assure effective tripping to protect the crew under the clearance. Any change to the values or trip settings puts the crew at risk.

Q: With all the talk about grounding, cover-up, EPZ and minimum approach distances, we have been debating the best practice for setting steel poles in energized 138 kV. A big question is, what class gloves should ground personnel wear while handling the pole? How can Class 3 or 4 gloves protect against 138 kV?

A: The short answer is that a Class 4 glove won’t protect against 138 kV. However, if you do it right, there is a very good chance you won’t be exposed to 138 kV even if you do get the pole in the 138. Here is how and why. At transmission voltages, we rely on planning, equipment setup, and precise/predictable control of the equipment and airspace to prevent contacts. We then take additional equipotential bonding actions to protect against a worst-case scenario like loss of control and pole contact with a circuit.

Here are some recommendations for those additional actions. Grade the work area. Grading the area flat around the pole hole gives the crew space for equipotential mats or grids. In best-case planning, it is ideal to stand the pole up with little hands-on contact until you get to the grabbers. If you are using portable mats, the prime location is at the stand-up/grabber location. During handling, the crew members on the pole butt will be in an EPZ. The pole then gets swung to the hole without crew contact. At the hole, mats are used to line the hole for crew who will handle the pole setting. Many crews are now using cattle panels as grids to create equipotential mats in the pole-setting areas. The panels are available at feed stores, constructed of welded #4 steel wire and bonded to the ground rod to create a large walking area around the pole-handling area that will be at equal potential with the pole.

Q: We were recently sticking distribution for a small utility when the utilities inspector stopped us for not having safety latches on our hot hoist. We have now been told that OSHA requires safety latches, but we can’t find a rule for that in the OSHA 1910.269 standard. What are we missing?

A: This answer will surprise and confuse some safety folks, so we want to remind you that we are not necessarily advocating the information we provide – we are educating readers on the rules and best practices. In response to your question, you are not missing anything; there is no OSHA rule for our industry that requires safety latches on hooks. Latches make sense. With a latch, connections do not unexpectedly separate. However, hooks under strain do not unexpectedly separate either. Most hooks for hoists have a tab for installing a latch. Many come with latches, and many do not. In hot-sticking applications, it often is difficult to open a latch and remove a hook from a sling. OSHA does, however, have safety latch requirements for some vertical standards that have no effect on utilities.

Q: When does OSHA consider a pole hole an excavation requiring a barricade?

A: It depends on whether or how long the pole hole is open and/or unattended. The preamble has a discussion on pole holes in which OSHA, in a fit of practicality, agreed that if the hole is bored and the pole is set within a reasonable time – being tens of minutes – there is very little practical reason to install fall protection. However, if the hole is large enough that a worker could fall in even with the pole in place, then some measures should be taken. As a contractor, we would ensure spoils were stable and lay 6 to 8 feet of 12-inch scaffold board across the holes between pole and spoils to ensure stable footing and no void large enough that a person could fall through. The other issue is, a hole for what pole? Distribution is not an issue. Transmission starts to need activities for protection like the above. Some transmission holes are 50 inches for a pole that’s only 36 inches to allow for concrete ballast. Those are excavations. We know many contractors that have used half of a round hay-bale feeder from Tractor Supply Co. as a guardrail.

Q: I am brand new to the safety side of contracting and need guidance on finding information about heat stress. There are lots of guides on assessing heat illness as it occurs, but what about industry practices to prevent heat stress? What do successful heat-stress prevention plans look like?

A: We have three recommendations for you. First, some state plan safety and health agencies – such as California’s – have mandatory program requirements that include trigger temperatures. When a worksite reaches such a temperature, certain site practices for heat stress must be employed. Section III, Chapter 4 of the federal OSHA Technical Manual (see www.osha.gov/dts/osta/otm/otm_iii/otm_iii_4.html) also has detailed information about heat hazard assessments and programs.  

Second, call your local hospital or favorite occupational medicine specialist and review your heat-stress prevention plan with them. In the past, I have offered to pay a fee to have a doctor visit a safety meeting to talk about prevention, although doctors usually will come to speak for free.

Third, do just as you have done: Ask questions, and share information with individuals and companies that have good, effective programs.

Q: Whenever we see graphics for single-point grounding, it’s always a cluster, a connection to the neutral, a connection to a phase and a chain connecting to the other two phases. But when we check with other utilities or consultants, we see all kinds of arrangements, such as bracket grounds with a single point or two sets of single-point grounds bracketing the workspace. Where do we find the definitive arrangement, and why are there so many variations?

A: Under OSHA, the employer is solely responsible for determining how they will meet the requirements of 29 CFR 1910.269(n)(3), “Equipotential zone,” which requires that grounding of de-energized phases be installed in an arrangement that prevents employees from being exposed to differences in electrical potential. In addition to 1910.269(n)(3), there also is Appendix C to 1910.269, “Protection From Hazardous Differences in Electric Potential,” as well as IEEE 1048-2016, “IEEE Guide for Protective Grounding of Power Lines,” a consensus standard that may be considered the authoritative best practice. IEEE 1048 is filled with detailed electrical data – from modeling to application – to explain how to create equipotential protection and effective tripping of grounded circuits that may inadvertently be energized.

Q: Recently an event occurred during a trouble job that surprised us. We had an underbuild phase down that was broken midspan. Our crew was working from an insulated bucket, and we grounded both the feeder we were working on and the one above. While our crew was beginning to crimp the splice for the repair, an energized line a few spans away came in contact with the grounded phase our lineman was in contact with. The lineman was in an insulated bucket, but he still received a shock. He was not seriously injured. Can you help us understand this?

A: The explanation is simple. Grounded circuits will still have current flowing through them if they are energized. Where there are resistances in parallel paths with the grounded circuit, there will be a voltage drop and there will be current flow through the parallel path. The current level is limited by the resistance in the path. Insulated bucket trucks are not totally isolating. To confirm that, all you have to do is look at the electrical tests performed on insulating booms. The current flow on an insulating boom is limited to a value well below the current necessary to injure a worker. In your case, there was voltage drop in the gap between the grounded, energized phase and the insulating boom that was a path to ground. Your lineman bridged that gap when he was in contact with the phase while standing in the bucket. The voltage was high enough to penetrate his skin so that current could flow. He was protected from injury by the current-limiting function of the insulating boom. We know it takes about 50 milliamps of current through a worker to rise to the level of injury. Depending on the electrical integrity of the boom and the voltage involved, there were – and this is just a guess based on boom-test protocols – perhaps 50 microamps to 1 milliamp of current that could flow on the boom. That is well below the level of injury. Electrical integrity of the boom is paramount in protecting workers. That is why it is critical to wash and maintain the boom.

Editor’s Note: This installment of “Q&A” addresses some common questions Incident Prevention receives throughout the year. Most are misunderstandings of the wording or intent of OSHA standards. From time to time iP has addressed the following scenarios – or similar ones – because they never seem to go away. In the following answers, the research or interpretation methods employed have been summarized to help readers become more familiar with interpretation and construction of the standards.

Q: Does OSHA 29 CFR 1910.269(l)(12), “Opening and closing circuits under load,” prohibit the use of non-load-break dropout fused switches or lifting of hot-line clamps to break loads? The rule reads as follows: “(i) The employer shall ensure that devices used by employees to open circuits under load conditions are designed to interrupt the current involved. (ii) The employer shall ensure that devices used by employees to close circuits under load conditions are designed to safely carry the current involved.”

A: This rule often is mischaracterized as prohibiting opening or closing under load using a non-load-break switch or a bare hot-line clamp. The rule does prohibit opening or closing a switch or hot-line clamp (“device”) under load if the employee performing the task could be injured by the act. If the employee can safely perform the act, there is no violation. To explain, there are two keys to properly interpreting this rule. One is the location of the rule; it is found in 1910.269(l), “Working on or near exposed energized parts.” The purpose of the paragraph is protection of employees, as stated in the section following the title: “This paragraph applies to work on exposed live parts, or near enough to them to expose the employee to any hazard they present.”

When OSHA reviews potential violations of the standard, they typically consider three issues: if there was a rule in place, if the employer knew about the rule and if an employee was exposed to danger by violating the rule. OSHA also will review consensus standards and best practices, as well as unadopted consensus standards, which sometimes are used in de minimis conditions and General Duty Clause violations. We know this because when we read public notice citations, we find unadopted consensus standard language used in the notice of violation without reference to the unadopted standard.

Q: I understand OSHA has made a final announcement on minimum approach distances. Can you explain the latest information?

A: On December 22, 2016, OSHA issued a memorandum to regional administrators regarding the enforcement of minimum approach distance requirements in 29 CFR 1910.269 and 1926 Subpart V (see www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=INTERPRETATIONS&p_id=31079). The memorandum had an effective date of July 1, 2017. Readers will recall that concerns about the rising risks of transient over-voltages were the basis for the increased minimum approach distances published by OSHA in 2014. The bottom line is that OSHA has accepted an industry engineering analysis – an IEEE paper titled “Practical Approaches to Reducing Transient Overvoltages Factors for Live Work” that was delivered at IEEE’s 2016 ESMO conference – as a basis for the final guidance of the memorandum. The guidance for enforcement is simple, but it is divided for above and below 72 kV. Following are the choices spelled out in the memorandum.

New Transient Table
The IEEE paper established a new Table A with standard transient multipliers based on voltage. The employer may still calculate their own minimum approach distances utilizing an engineering analysis approved by the standard using transients published in the new Table A.