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October-November 2021 Q&A

Q: We are contractors with a truck grounding question for work inside substations. Working within a proper clearance, the generation and transmission cooperative (G&T) that owns the transmission circuit coming into the substation believes 4/0 equipment grounding is needed, while the consumer utilities operating the substation say 1/0 or 2/0 is required. We sometimes are required by the G&T to use double 4/0 to meet the required available fault current. Can you explain the disparity in requirements? Also, do we meet the OSHA requirements if we use the 1/0 or the 2/0 for equipment grounding on manlifts when working within the minimum approach distance in a de-energized area that is locked out and tagged out?

A: This must be a multifaceted answer, and perhaps explaining why there are so many opinions will be more valuable than how to make a grounding decision on your own. There are various opinions, such as you describe, because there are many ways to look at both the OSHA rules and what engineering is assuming the exposure to be as well as what they are trying to accomplish.

The G&T is familiar with the maximum available fault current associated with their lines entering the substation up to the first circuit switch. The substation operator is familiar with the maximum available fault current beyond the impedance of the power transformer and the bus systems that they design and protect. The values are different between the two systems. In addition, there are different ways of calculating fault, especially if the calculation adds in buffers or safety factors that affect the outcome. We often find that engineers are uncomfortable with anything less than overbuild when they know they are calculating against the lives of workers in the substation.

It seems logical that the ground cable used on a manlift should be the same as the grounds calculated to ground the bus, but that is not necessarily the guidance that comes from OSHA. The preeminent rule for grounding mobile equipment is 29 CFR 1910.269(p)(4)(iii)(C) for general industry or 1926.959(d)(3)(iii) for construction. We are paraphrasing here due to space limitations, but both rules require that if the employer cannot ensure employees are protected from accidental energizing of the equipment by the methods in use, then the equipment must be grounded to the best available ground, bonded together, equipotential matted and barricaded. The OSHA standard does not describe in any reference how the grounds should be sized, only that the grounds minimize the time the lines or electric equipment remains energized. To minimize the time the lines remain energized means that the grounded lift must be able to trip the circuit protective device of the lines in contact with the lift. That seems to indicate that appropriately sized grounds are called for. When OSHA calls out ground sizes, they usually refer us to 1926.962(d)(1)(ii) (protective grounding equipment shall have an ampacity greater than or equal to that of No. 2 AWG copper) and 1926.962(d)(2) (protective grounds shall have an impedance low enough so that they do not delay the operation of protective devices in case of accidental energizing of the lines or equipment). There again is language that suggests sizing an equipment ground according to fault current. But that isn’t the only solution. If we look closely at the rule for grounding, 1910.269(p)(4)(iii)(C), a portion of it reads “methods in use.” If the methods used ensure the worker cannot be electrocuted by contact with the lift, then the size of the ground or even whether you ground at all is inconsequential. If the work hazard assessment determines that the lift is isolated, the bus is de-energized and grounded, there is no possible contact with the energized bus or equipment, and work rules prohibit workers on the ground from approaching the lift, then the employer can ensure the worker is protected by the methods in use. If that’s the case, 1910.269(p)(4)(iii)(C) is satisfied with no grounds or with small grounds if no one is comfortable with not grounding simply out of habit in the substation.

Incident Prevention does not intend to be critical of the engineers who decide your work policy as it is their responsibility to make these determinations and we cannot judge their intent or methodology in this forum. What we do is help to clarify the standards as we understand them. It is the employer’s responsibility to decide how safe work is to be done, and workers must follow the employer’s rules. If we can help the parties understand the rules or see them in a different light, it sometimes makes the work easier on everyone while maintaining worker safety at the highest level.

Q: Thank you for offering this platform where we can get answers from a utility safety perspective. We recently had an incident with a minor injury on a distribution construction site, where a helper was struck by a Cat 962 wheel loader equipped with forks. The injury required an overnight hospitalization and State Plan OSHA did an inspection. OSHA returned a citation for failure to train under the powered industrial truck (PIT) standard. They said in the informal conference that we were using the loader as a PIT, so the citation is appropriate. Are they correct?

A: First, as a reminder, Incident Prevention is not offering legal advice here. What we do in this column is offer opinions from highly experienced industry professionals regarding rules and standards related to the utility industry.

As to your question, we reviewed your state’s occupational safety standards, and in our opinion, the answer is no – OSHA’s reasoning and citation are incorrect. On a wheel loader, even if it is equipped with forks, citing operator training under the PIT standard is incorrect.

Your state plan adopted the federal OSHA standards in their entirety without changes. This is the third such citation we are aware of in the past few years where both State Plan and Federal OSHA have incorrectly cited an employer in loader-related incidents. One citation was given to an investor-owned utility and two others were given to contractors. OSHA is run by humans and humans make mistakes, but we hope this is not a trend with OSHA. We also hope that you will contest the citation. Your operator may have erred, and you may be responsible, but you may be responsible under the appropriate standard – not the PIT standard. OSHA has a lot of power and when they go off the rails, industry needs to correct them. We wouldn’t want an incorrect OSHA citation to set a precedent that alters 30 years of exceptions for loaders.

The 900 series wheel loaders are popular and have been used on construction sites to move dirt and handle poles under the PIT exception for decades. The exception is justified because loaders have center frame articulated steering with completely different mechanical and stability characteristics than forklifts. The loader cannot meet the PIT standards in operation or training. The current requirement is for an employer to ensure an operator is qualified, and that qualification – earned through training or experience – has proven to be more than sufficient.

Loader incidents are not an issue in our industry. You can find the exceptions defined by OSHA in 1910.178(a)(1) and in the preamble to the final rule regarding the powered industrial truck standard, dated December 1, 1998. You can also find the exception in the OSHA-recognized ANSI B56.6, “Safety Standard for Rough Terrain Forklift Trucks.”

Q: What is the first thing you would do to reduce incidents and improve safety at a power-line contractor?

A: Train your supervision. In fact, in this issue, Jim Vaughn’s “Train the Trainer 101” addresses this same topic in broader terms of cultural change. Your supervisors are your frontline, hour-by-hour bridge between the employer’s programs and the crew’s execution of those programs. Supervisors can play a key role in building safety culture when they understand that role and have the requisite knowledge about and buy-in of the role. Too many employers fail to train supervisors, relying on their experience as craft professionals to fill that gap. But without in-depth safety training, supervisors will never know how important they are to the safety culture success that protects employees, and the employer loses the safety resource that comes from a well-trained supervisor.

Q: What is an employer’s affirmative defense relative to an OSHA charge, and how does it work?

A: For the second time this issue, we must preface this discussion with a disclaimer. Incident Prevention is not offering legal advice. We do have opinions based on our experience with OSHA cases, in which affirmative defenses – usually employee misconduct – have been used to contest a citation right up to the courtroom.

In simplified terms, an affirmative defense is when an accused party puts forth alternative claims or facts to challenge the claim against them, even if the facts of the claim are true. Here’s an example of a common scenario in which an affirmative defense is claimed by an employer. OSHA investigates an incident that resulted in an injury to an employee and finds the employer responsible. The agency issues a citation for violation of a certain rule. The employer responds to OSHA’s complaint, showing that they did everything they were supposed to do and that the employee violated the rules they were trained to follow outside the control of the employer. Most successful affirmative defenses have demonstrated that the employer’s safety manual rules and training, if followed, would have protected the employee from injury. The phrase “employee misconduct” does not necessarily mean the employee was willful or egregious in their actions. People make mistakes even if they are well-trained and known to be conscientious. The employer would have to show that the rule was communicated to the workforce by training; that supervisors and other employees were trained to comply with the rule; that supervisors enforced the rule; and that a disciplinary program effectively remediated employee noncompliance with safety rules. If the employer successfully puts forth that defense, and they can demonstrate the employee violated the rule outside of the control of the employer, then the employer showed due diligence and cannot be held responsible for a condition over which they had no control, such as employee misconduct.

It is our understanding that in Canada, affirmative defenses can be successfully argued in many jurisdictions. The terminology and process may change, but the premise remains the same. A defense can be established if the employer has developed appropriate safety systems, workers and supervisors have been trained, and employee noncompliance with a safety system has been documented. The provincial occupational health and safety acts use language such as “reasonably practical,” thereby creating a system of strict liability and providing an opportunity for a due diligence defense. An employer can argue that an employee has “removed himself or herself from the course of employment” if they have intentionally deviated from the known expectations and conditions of employment.

In both the U.S. and Canada, there are attorneys who know the rules of defense in occupational safety citations and can give legal advice to assist employers in dealing with and defending themselves against claims. What we do as safety professionals is ensure the employer has a defensible safety manual, training and supervision, as well as a functional discipline program for noncompliant employees.

Do you have a question regarding best practices, work procedures or other utility safety-related topics? If so, please send your inquiries directly to Questions submitted are reviewed and answered by the iP editorial advisory board and other subject matter experts.

Q & A

Jim Vaughn, CUSP

After 25 years as a transmission-distribution lineman and foreman, Jim Vaughn, CUSP, has devoted the last 24 years to safety and training. A noted author, trainer and lecturer, he is a senior consultant for the Institute for Safety in Powerline Construction. He can be reached at