August-September 2025 Q&A

Q: If a crew is setting a steel pole between energized phases (69 kV), would the 3.29-foot minimum approach distance found in OSHA Table 6 apply, or should we defer to the 15-foot clearance?

A: Setting poles is new construction that OSHA covers in 29 CFR 1926.960, Table V-5, “Alternative Minimum Approach Distances for Voltages of 72.5 kV and Less.”

There is cover rated up to 72 kV phase to phase, so for a 69-kV system, cover can be used. Without cover, an electrical crew can use the 3.29-foot MAD for phase to ground. If cover is not used and a conductive object could enter the electrical component air gap for both adjacent phases of the 69-kV system, the 3.94-foot phase-to-phase MAD would apply.

MAD applies when work is being done by a qualified electrical crew and an electrically trained, qualified operator. The standard clearance applies when the crew members and equipment operator aren’t qualified.

OSHA’s rule states that no employee shall approach closer than the MAD unless they are insulated by gloves or the energized part is insulated by cover. You can choose either option. In the example you provided, cover is preferred because of the issues with load control. Of course, another option is spreading phases to increase space. There is no cover rated for system voltages above 69 kV, so isolation for 115 kV and above is the method to use.

Q: We are a small utility with few resources seeking guidance about layering arc-resistant PPE garments to achieve greater protection. We have some exposures in pad-mounted switching calculated at Category 4, and we understand the following:

• Layering two garments does not result in a simple mathematical combination of their individual arc ratings.
• Only testing can truly determine the protection of two garments worn together.
• The gold standard is to match garment ratings with assessed hazards.

With that said, it seems logical that two AR garments worn together would yield higher-level protection. My question is, can we layer Category 3 sweatshirts and medium-weight jackets over Category 2 shirts for tasks with arc risks greater than the rating of the Category 3 garments? Because we’re ideally looking for price deals, we don’t restrict garment procurement to one manufacturer. That makes testing each layer combination impractical and far outside our budget. Do you have any thoughts or suggestions?

A: It might be justifiable and worthwhile to partner with just one garment vendor to meet your obligation to your employees. Combination testing is required to ensure worker protection levels. A manufacturer is unlikely to offer their lab results with a competitor’s product, and in your case, because you buy garments from various manufacturers, every purchase would be subject to a category value change. By opting to partner with a sole vendor, you gain access to information and support regarding layering designs and values.

As to your Category 4 URD exposures, the use of longer shotguns and sticks can move exposed workers farther from the source of an arc flash and may provide a way to keep exposures at Category 2. It’s the same with substations. Switching procedures can usually keep technicians far enough away that they rarely exceed Category 3, but we yield to your source calculations.

The bottom line is that you’re right. OSHA states that you cannot assume the combined arc thermal performance value, or ATPV, of layered materials because, as you said, they are not 1:1. If you’re layering garments made by more than one manufacturer to achieve a certain ATPV, OSHA’s expectation is that you tested the layers together using the industry-required standardized testing. On the other hand, if you’re layering garments from the same manufacturer, they have either already tested or will test the layers to identify the combined APTV.

Q1: Something came up during a grounding scenario that I’d never questioned before. Does OSHA require a visually verifiable air gap? Our answer to this was yes, absolutely, no question about it – it’s a widely agreed-upon best practice. But we have a utility customer who told us an open is verified by checking for the absence of voltage. Can you explain the correct approach?

Incident Prevention also received a second, related question from another reader.

Q2: We are working through the question of requiring a visual open on equipment owned by a big customer of ours. OSHA 1910.269(m), “Deenergizing lines and equipment for employee protection,” states that the employer must ensure disconnects, jumpers and other means are open. Having a visual open has always been the company procedure. In reading the regulation, however, I am struggling to understand what OSHA is saying. I think part of it is checking for lack of voltage, but the other part is having a visual on the contacts, whether that’s an open-air gap on a disconnect or one through a window on underground equipment. A camera that shows an internal target wouldn’t meet what I believe to be true. Can you help?

A: OSHA’s rules are open-ended, or what’s referred to as “performance based”; they state what must be accomplished. The employer decides how they will meet those expectations. A voltage check meets the requirement to ensure the facility is de-energized. The OSHA standard does not use the term “visual open” as a requirement. Whatever we decide to do, the procedure and solution employed to protect the worker must be defensible. We accomplish that by engaging in common industry practices.

In most cases, a visible open is only the beginning of protection for the worker. Ensuring that the open remains open and can’t inadvertently be closed is the second – and probably most important – part, especially where there are no “locks” that can be used to ensure an open switch stays open. Typically, the third part is having a written policy and/or training for those who rely on the open for their protection.

The OSHA rule calls out switches, disconnectors, jumpers and taps, and it requires the means to be inoperable. The standard doesn’t differentiate between untap and tape back or total removal. Jumper removal meets the obligation to be inoperable. The rule also requires tagging of the inoperable means, which must conclude with ensuring that no one with the capability could come by and replace a missing jumper. It’s the same with removing a barrel; you still tag for the highly unlikely but not impossible event that someone could come by with an extendo stick and a spare barrel.

The bottom line is that the open was created for worker protection and therefore must be tagged.

Most utilities frown on an open disconnect in an enclosure where the disconnect isn’t visible. For that reason, numerous manufacturers now offer view ports for visual observations of open contacts. A view port can be coupled with a locking or blocking mechanism, which is the second part (noted above) that ensures open contacts can’t be inadvertently closed.

Q: When and why did the industry begin using red for L1, white for L2 and blue for L3? Doesn’t the National Electrical Code standardize the colors on 240 volts (i.e., L1: black, L2: red and L3: blue) and 480 volts (L1: brown, L2: orange and L3: yellow)? Also, is there a different color code once you get above 480 volts?

A: Power-line installations are not subject to the National Electrical Code. We use the “X” and “H” 1/2/3 designations common to transformers, which are standardized in transformer consensus standards. In a single phase, X2 is a neutral bushing, but the conductor itself is usually bare past the bus jumper from the transformer. When we put notations in a customer’s meter, we typically use magic marker to label a 1/2/3 and rotational direction. We don’t color-code our line-side conductors; we use voltmeters.

The NEC does not designate phase colors, except the neutral being white or gray and ground wires being green or bare copper. The color conventions – red, black, orange, brown, and blue and yellow – are exactly that: conventions common to the electrical industry. So, what is required? If you put orange on one end of phase B, the other end of the same conductor must also be orange.

The purpose of using colors is to ensure workers can properly note phase rotation during the initial hookup. With single-phase, it doesn’t matter whether one is red or black or whether they’re the same at the other end. With three-phase, color was originally used to designate the high leg for open delta. Other colors have simply caught on, inspired by tape manufacturers and companies, like Brady, that make labels for wire.

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