Danger: High Voltage

Applying caution to electrical inspection:

I could not do my job as an inspector if I couldn’t open doors and covers of energized equipment; when I came aboard, they gave me a screwdriver and a flashlight and turned me loose. Of course, we were all electricians then.” So said a veteran electrical inspector at a recent International Association of Electrical Inspectors (IAEI) meeting.

I spoke to a number of electrical inspectors on this subject. Others said that they have combination inspectors under their supervision; they are instructed not to open anything electrical, but the electrical specialists can and do open equipment whether energized or not.

It was obvious from the conversation that all of the electrical inspectors regularly opened doors and covers of energized equipment. In no case was it reported that their employer (city, county, etc.) provided them with any personal protective equipment (PPE).

“My first day as an inspector, they gave me a hard hat and a pair of safety glasses,” said James W. Carpenter, CEO of the IAEI. “But today, IAEI teaches in all of our safety seminars that inspectors must follow the OSHA and NFPA 70E rules and use personal protective equipment whenever opening a cover of energized equipment where there is the possibility of arc flash or arc blast.” He said that he knew of no case of an electrical inspector being injured by arc flash or arc blast.

These days, however, it is becoming more common for electricians to be provided with PPE where the possibility of arc flash exists, but it appears that the same rules have not been universally applied for electrical inspectors.

Years ago, as the veteran electrician said, most inspectors were electricians, but now it is quite possible for a person with no electrical construction experience to pass a civil service test and be hired as an electrical inspector.

It is more likely that the ex-electrician/inspector will feel comfortable opening the cover of energized equipment because he has done it many times before with no harmful outcome. However, it only takes one incident to plant the seed of doubt, and in such a case, experience makes no difference.

Considering both points in uncertainty, we’re seeing a trend of a growing number of timid inspectors. If you open an energized box 1,000 times without incident, the possibility of an arc flash or blast leading to injury still exists. With such high stakes, it’s not surprising the inexperienced and the previously injured are reluctant to open energized equipment.

Furthermore, when 110.16 takes effect, the cost of electrical inspection is going to rise. It takes time for the inspector to observe the notice of arc flash hazard and then return to his vehicle to obtain and don the required personal protective equipment, if any has been provided. The clearly visible warning required by 110.16 is a field marking for non-dwelling occupancies. This is meant to be one- and two-family dwellings, for multi-family dwellings can have large services and large available fault current. The warning must be field-applied, for the manufacturer of the equipment cannot know the circumstances at the point of connection. Most importantly, the fault current available from the serving utility is the first consideration.

The utility in my area of northern California has a policy of serving one- or two-family dwellings with not more than 10,000 amperes of available fault current. However, it is possible for a dwelling to be located adjacent to a shopping center or other commercial occupancy and be fed from the same transformer, in which case the 10,000 amperes available cannot be ensured.

Due to the 110.16 warning that appears on energized equipment and the combined inexperience or, in some cases, experience with previous incidents, it is likely that requests for an electrician to be on the job to open enclosures for the inspector will increase, but that will not change the necessity for the inspector to use protective gear. Individuals standing behind the electrician doing the work have been injured, depending on how close they were to the arc flash, and the same could happen to an inspector who might get a little too curious.

Assistance in determining the severity of potential exposure and in selecting personal protection equipment is found in NFPA 70E-2004 “Standard for Electrical Safety in the Workplace.”

The basic rule is to work only on deenergized equipment. The disconnect should be opened, locked out and tagged and the absence of voltage verified by test. Remember, you shouldn’t think just because no one has been hurt before you can get careless.                EC

SCHWAN is an electrical Code consultant in Hayward, Calif. He can be reached at creighton.s@sbcglobal.net.


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