Construction: How many 100' extension cords can be daisy chained together legaly?

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eric9822

eric9822

Senior Member
Location
Camarillo, CA
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Electrical and Instrumentation Tech
LarryFine said:
No, but plug-in testers do.
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Very true but unless something has changed an OSHA inspector can only use an external tester to prove that a GFCI is in use and not prove that a GFCI is not in use. If an external tester fails to trip a receptacle then the inspector is supposed to investigate further to determine if there is a GFCI upstream.
http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=INTERPRETATIONS&p_id=24545

wtucker said:
OSHA Construction Industry Standard, as requested:

1926.404(b)(1)(ii) ?All 120-volt, single-phase 15- and 20-ampere receptacle outlets on construction sites, which are not a part of the permanent wiring of the building or structure and which are in use by employees, shall have approved ground-fault circuit interrupters for personnel protection. Receptacles on a two-wire, single-phase portable or vehicle-mounted generator rated not more than 5kW, where the circuit conductors of the generator are insulated from the generator frame and all other grounded surfaces, need not be protected with ground-fault circuit interrupters.?

All receptacles need GFCI's, from the one the extension cord's plugged into on downstream. If that one doesn't have a GFCI, it's acceptable to put a portable one there--on the supply side of the cord. Best choice is a GFCI breaker on each branch circuit (the title of .404(b) is "branch circuits").

OSHA doesn't care how long the extension cord is, unless the cord's being used contrary to its UL listing. The problem's the gauge of the conductor. Overheating and voltage drop...
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Thank you, I am aware of that standard. I was asking tkb to reference the standard he keeps quoting that states GFCI's must be at the end of an extension cord vs. at the receptacle supplying the extension cord.
 
W

WorkSafe

Senior Member
Location
Moore, OK
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Electric-Light

Electric-Light

Senior Member
I believe its kosher to use a 3-prong GFCI receptacle on a building lacking ground as long as its marked
"GFCI Protected” and “No Equipment Ground". A GFCI will read a false negative on a functional GFCI in such setting.

plug-in GFCI tester is like the test button on a smoke detector. It creates leakage current to the ground by using equipment ground.
 
Electric-Light

Electric-Light

Senior Member
If you have a GFCI on the end, but fed from a non-GFCI source and the cord-to-cord connection gets wet in the bed of a pickup, someone can get shocked from the energized vehicle and GFCI on the end won't even sense it.

Connectors like this are water proof. They're often used in connecting sections of extension cables between generator trailer farm and spiderbox at state fairs, concerts, carnivals and such.

http://www.go2marine.com/product.do?no=70922F

Just because the cord is SJTOW doesn't mean the ends are designed to run through puddles and such usage, I believe is in contrary to listed use.
 
weressl

weressl

Esteemed Member
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Texas by the Gulf, geat crab, great shrimp
EDawes said:
A 46,000 sq foot building site has the steel skeleton up with the 2nd floor deck serving as a porous roof. They are using corded drills to screw pre formed panels for the walls. 6 to 8 drills are plugged in at one time. 4 duplex (GFCI) outlets are wired in a wall by the entrance. A 20 amp breaker is on the outlets. They are running a 50 ft cord with a spider box. They are running 5 100 ft cord in series to reach men on the far wall. The spider is also GFCIed. A proven gfci tester will not pop either GFCI in the cuircuit. All cords are 12 hard service. Aside from wiring the building is there a good solution to this long run? The GFCI TESTER still works on regular GFCI outlets but will not pop this one with 2 GFCIs in series?
Click to expand...

None.
 
eric9822

eric9822

Senior Member
Location
Camarillo, CA
Occupation
Electrical and Instrumentation Tech
E

EDawes

Member
GFCI on CORD END?

GFCI on CORD END?

OSHA failed to clarify to my satisfaction which end must have the GFCI.
One responder made the point that the cord as well as a tool could be the hazard therfore BOTH ends need protection.

NEC on no ground wire:

If no equipment grounding conductor exists in the outlet box for the receptacle, such as old 2-wire Type NM cable without an equipment grounding conductor, existing nongrounding-type receptacles can be replaced with [406.4(D)(2)]: Figure 406-04D2 01
? A GFCI-type receptacle marked ?No Equip?ment Ground?, or
? A grounding-type receptacle, if GFCI protected and marked ?GFCI Protected? and ?No Equipment Ground.?
Author?s Comment: GFCI protection functions properly on a 2-wire circuit without an equipment grounding conductor because the circuit equipment grounding conductor serves no role in the operation of the GFCI-protection device. Figure 406-04D2 02

OSHA General Industry on No Ground Wire:

A nongrounding-type receptacle may be replaced with a ground-fault circuit-interrupter-type of receptacle that is marked "No Equipment Ground;" an equipment grounding conductor may not be connected from the ground-fault circuit-interrupter-type receptacle to any outlet supplied from the ground-fault circuit-interrupter receptacle.

Standard: 29 CFR 1910.304(b)(2)(iv)(C)(2)

Thanks for the synergy of your combined knowledge and experience.

ed
 
kwired

kwired

Electron manager
Location
NE Nebraska
EDawes said:
OSHA failed to clarify to my satisfaction which end must have the GFCI.
One responder made the point that the cord as well as a tool could be the hazard therfore BOTH ends need protection.
Click to expand...

And if the protection is at the source end then BOTH ends are protected.
 
D

dg

Member
How many extension cords can be daisy chained together?

How many extension cords can be daisy chained together?

My guess is zero. I think the cord set was probably tested and UL-listed for use from a receptacle to a tool. Check the manufacturer's literature that comes with the cord.
 
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