NEC 70E Question

[Steve Merrick]

Our Safety Department has shutdown routine troubleshooting activities at our facility such as voltage testing in 120V control panels, unless full Cat 2 PPE is used along with V-rated gloves and tools.

Here are a few questions I need help with:
Since IEC IP20 compliance is intended to prevent inadvertent contact with exposed conductors, and since everything inside the panels is IP20 finger-safe compliant, are there any "exposed" live parts in the panel for 70E purposes? Can we just look inside a control panel from closer than 4 feet but not touch without putting on a flash-hood, etc.?

NEC 70E Table 130.7(C)(9)(a) applies a Hazard Category 1 for voltage testing in a panel 240V or less, and requires use of V-rated gloves and tools. We are using UL listed voltmeter probes to contact recessed finger-safe terminal screws. Why would that activity require a flash hazard analysis, hot work permit, rubber gloves, safety glasses, etc.? We first test the voltmeter by inserting the probes into a live 120V receptacle in accordance with the manufacturer's instructions, and we don't require a hot work permit for that. How are these two activities different? By the same logic, simply plugging an appliance into a receptacle could be considered "live" work. Receptacle contacts are just as inaccessible as IP20 rated terminals and we don't require a permit and PPE to plug in an extension cord... What are we missing?

I would really appreciate any help you can give me on this subject. It has turned into a huge issue at our facility - all troubleshooting work is now stopped - and it illustrates the wide variety of interpretations of NEC 70E requirements.

Thanks!
Steve

 

[tom baker]

Re: NEC 70E Question

The amount of safety gear is driven by the fault current. Have you checked the available fault current?

 

[Steve Merrick]

Re: NEC 70E Question

Yes, it has about 7200A short circuit current available. This allows Note 3 on Table 130.7(C)(9)(a) to kick in to allow us to reduce the hazard category to zero. I pointed that out to the Safety guy who replied, "That's fine, but the table still says that to work on any energized part 'including voltage testing,' you still need to use V-rated gloves and tools."

I don't agree. I still maintain that touching a UL listed volt probe to a recessed, finger-safe terminal is no more hazardous than plugging an appliance into a receptacle. After all, a receptacle qualifies as an "energized part." Where am I off base?

Thanks!

Incidently, I'm the head of our electrical safety committee and the AHJ for the facility, and I want to make sure that my ruling on this is well founded. All of the Journeymen electricians on the committee agree with my position, but the Safety organization has stop-work authority and I don't want to overrule them unless I'm sure my position is correct.

Thanks again,
Steve

[ August 22, 2005, 03:38 PM: Message edited by: Steve Merrick ]

 

[don_resqcapt19]

Re: NEC 70E Question

Steve,
Voltage rated gloves and tools are required any time you use a tool of any type to touch an energized part.
Don

 

[jim dungar]

Re: NEC 70E Question

NFPA70E
130.1(A)(3) says "live work" permits are not required for tasks such as testing for voltage.

110.9(B)(4) addresses plug and receptacle connections. While it says gloves are not always required, I see no exception for arc flash protection.

Finger safe is not the same as enclosed construction. IMO as long as an uninsulated voltage probe contacts an energized screw the protection provided by finger safe construction is breached.

 

[Steve Merrick]

Re: NEC 70E Question

Thanks for all of your responses. You've been very helpful.

As I've considered this, I wonder if the definition of "Exposed (as applied to live parts)," under Article 100 takes care of this dilemma. It states that a part is exposed if it is "capable of being inadvertently touched... by a person. It is applied to a part that is not suitably guarded, isolated, or insulated."

Clearly the terminals on a receptacle are "guarded" and "isolated," and thus not "exposed;" therefore Article 130, Working On or Near Live Parts does not apply when plugging in your computer. If this is a correct interpretation, the same logic should apply if all energized parts in a panel are IP20 compliant finger-safe devices. The terminal screws on an IP20 device are guarded and isolated, thus not exposed.

Thoughts?