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ekstra   ara
 Post subject: 120VAC Voltage Testing
PostPosted: Mon Jun 26, 2017 5:39 am 

Joined: Thu Jun 22, 2017 4:42 pm
Posts: 3
Looking for clarification on the required PPE and ARC Flash interpretation for voltage testing within a Control panel fed with a 120VAC single pole 20A circuit breaker. All terminals are finger safe. Table 130.7(C)(15)(A)(a) says "For ac systems: Work on energized electrical conductors
and circuit parts, including voltage testing" that Arc Flash PPE is required. Table 130.7(C)(15)(A)(b) defines the PPE required as Category 1. "Panelboards or other equipment rated 240 V and below 1 485 mm Parameters: Maximum of 25 kA short-circuit current available; maximum of 0.03 sec (2 cycles) fault clearing time; working distance 455 mm (18 in.)". This seems excessive. Interested to hear how others are doing this.


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 Post subject: Re: 120VAC Voltage Testing
PostPosted: Mon Jun 26, 2017 8:24 am 
Sparks Level

Joined: Fri Apr 15, 2011 7:43 am
Posts: 177
Location: Colorado
PPE required - yes. What PPE????? There is not even a "good" way to calculate single phase 120V!

That table only applies to those listed conditions. It is doubtful they all apply in every situation - therefore a study needs to be done but no study can be applied to 120V single phase. HMMMMM the conundrum!!!!!!

I think if you did a calculation you would find the AFB to be extremely small and the IE to be small also.

If your company is requiring PPE then they must provide it.

The risk assessment needs to look at more than arc flash!!!!


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 Post subject: Re: 120VAC Voltage Testing
PostPosted: Mon Jun 26, 2017 5:17 pm 

Joined: Mon Oct 10, 2016 12:38 pm
Posts: 15
Hi All

I agree with the comments made earlier. At 120VAC I would consider that electrical shock is the possible hazard in oppose to one receiving burns as a result of an arc flash. You have mentioned that the terminals are finger/ touch safe, or sometimes referred to IP 20, which in your case means allot with regards to any PPE. In addiiton to the other sections in 70E that you have referenced, I would consider reviewing article 130.4D on page 25 of 70E:

D) Restricted Approach Boundary. No qualified person
shall approach or take any conductive object closer to exposed
energized electrical conductors or circuit parts operating at
50 volts or more than the restricted approach boundary set
forth in Table 130.4(D)(a) and Table 130.4(D)(b), unless one
of the following conditions applies:
(1) The qualified person is insulated or guarded from the
energized electrical conductors or circuit parts operating
at 50 volts or more. Insulating gloves or insulating
gloves and sleeves are considered insulation only with
regard to the energized parts upon which work is being
performed. If there is a need for an uninsulated part of
the qualified person’s body to contact exposed energized
electrical conductors or circuit parts, a combination
of 130.4(D)(1), 130.4(D)(2), and 130.4(D)(3) shall
be used to protect the uninsulated body parts.
ARTICLE 130—WORK INVOLVING ELECTRICAL HAZARDS 130.4
2015
(2) The energized electrical conductors or circuit part operating
at 50 volts or more are insulated from the qualified
person and from any other conductive object at a
different potential.
(3) The qualified person is insulated from any other conductive
object.

I would say that you easily satisfy (2) above. This is not all, please refer to Table 130.4D(a) on page 26. For voltages 50-150 V "Avoid Contact". Which one could say avoid making contact with exposed energized conductors or circuit parts. However in Note d, found below This includes circuits where the exposure does not exceed 120V. So in other words yes 120V could be potentially lethal from a shock perspective. But from what you have described above you are dealing with equipment that is finger safe- no exposed parts- provided it is 100% finger or touch safe. My take is no PPE, not even rubber insulating gloves with leather protectors


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