70E and the Limited Approach Boundary

[al]

I am having trouble with 110.8

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110.8 Says:
"(1) Energized Electrical Conductors and Circuit Parts
? Safe Work Condition. Energized electrical conductors
and circuit parts to which an employee might be exposed
shall be put into an electrically safe work condition before
an employee works within the Limited Approach Boundary
of those conductors or parts, unless work on energized
components can be justified according to 130.1."

If I read this correctly I could not do the following tasks without justification:
1. Change out an energized edison base light bulb.
2. For a control panel with 120VAC energized parts I could not change out a plug in relay within 3-1/2' of the energized parts or connect a laptop to a PLC
in that enclosure.
3. Change out flourescent bulbs that are energized.
4. If I plug in a regular NEMA 5-15 plug to a 120VAC receptacle there is about 1/2" of exposed energized conductor about 3/4" from my hand as I am plugging it in.

Is this a correct intrepretation?
Are the above items considered work?

 

[billsnuff]

Has an Arc Flash Study been done?

See Table 130.7(C)(9).

 

[pfalcon]

If I read this correctly I could not do the following tasks without justification:
1. Change out an energized edison base light bulb.

um, Why would you want to shorten the life of the bulb? Turn it off.

2. For a control panel with 120VAC energized parts I could not change out a plug in relay within 3-1/2' of the energized parts or connect a laptop to a PLC
in that enclosure.

You can with finger-safe components. Better, extend a port to the outside of the cabinet. We are now requiring "Daykin LFTB-07 Z1183" or "Daykin LFTP-05 Z1183" that have integral GFCI breakers on ports and lights.

3. Change out flourescent bulbs that are energized.

See 1.

4. If I plug in a regular NEMA 5-15 plug to a 120VAC receptacle there is about 1/2" of exposed energized conductor about 3/4" from my hand as I am plugging it in.

=)

 

[iwire]

um, Why would you want to shorten the life of the bulb? Turn it off.

Um, how would screwing an Edison base lamp in live shorten it's life anymore than flicking a switch?

 

[petersonra]

Um, how would screwing an Edison base lamp in live shorten it's life anymore than flicking a switch?

The light startles him when it comes on and he falls off the ladder?

 

[al]

Finger Safe??

Finger Safe??

pflacon,


You can with finger-safe components. Better, extend a port to the outside of the cabinet. We are now requiring "Daykin LFTB-07 Z1183" or "Daykin LFTP-05 Z1183" that have integral GFCI breakers on ports and lights.

How have you determined that finger safe are not considered live enegized parts?

 

[zog]

How have you determined that finger safe are not considered live enegized parts?

Look at the "Exposed" definition in the 70E..

 

[mivey]

Um, how would screwing an Edison base lamp in live shorten it's life anymore than flicking a switch?

The vibration might shorten the life. You probably would have to be a bit clumsy for normal bulbs, but some are persnickety.

 

[mivey]

3. Change out flourescent bulbs that are energized.

I would not recommend it.

Believe it or not, you can get shocked doing that. I have on a 4' 120 volt fixture. The arc went from the tube, through my finger, and to the can.

I have also been doing that on an 8' lamp and had 277 blow a hole in the ballast cover.

 

[pfalcon]

Um, how would screwing an Edison base lamp in live shorten it's life anymore than flicking a switch?

Frequently when they're being screwed in they flicker rapidly as it approaches full contact. The inrush damages the filament. Admitedly I don't know how many hours it shortens the life. And yes, every time you flick the switch on it shortens the life. Probably shortens it far less than my falling off the ladder does mine.

The light startles him when it comes on and he falls off the ladder?

That would be my life, not the bulb :O