Temp light

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mstrlucky74

Senior Member
Location
NJ
Anyone have a rule of thumb they use for figuring out how many 50 or 100' light stringer they use for a space....sq ft etc. ? Thanks
 

mgookin

Senior Member
Location
Fort Myers, FL
Anyone have a rule of thumb they use for figuring out how many 50 or 100' light stringer they use for a space....sq ft etc. ? Thanks

You can best estimate that by looking at your floor plan. Every room needs 1 light minimum if you don't want to work in the dark, and two would be nice so you don't have the dark shadow.
 

cadpoint

Senior Member
Location
Durham, NC
Have not done much renovation work. If you have a commercial space about 25k sq ft and it will be a complete gut(demo). What do you usually use for temp light? Light stringers and stands? Thx

Anyone have a rule of thumb they use for figuring out how many 50 or 100' light stringer they use for a space....sq ft etc. ? Thanks

State the X and Y of building. Tell us what you decide in respects as to wattage of the lamps your going to use. I'd go with Infinity's suggestion Of MH in large to remain open area's.

Looking on the net it says that max. 150W lamps for bird cage lamps. MH is more bang for the bucks, but is a different summary equation.

I'd consider four or five strings of twist cork screws at maximum wattage you can find and maybe intermixed with two or three MH.

Two maybe three strings for power poles.

You buildings square footage is not much bigger than my last job, but mine was a two story, but the building had enough windows that there weren't dark spots so it didn't didn't matter.
there was on four non windowed rooms.

W= A x V... (continious - loading)

So your up to a 100 Pole service and sized to maybe eight breakers.
 

iwire

Moderator
Staff member
Location
Massachusetts
Stringers are made up of 12/3 NM cable with one lighting and one power circuit. Here's some regional lingo, the lamp is installed in a left handed socket and the power is from a laundry drop.

In my opinion that is still an NEC violation.

You have lights and receptacles on the same MWBC.
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
In my opinion that is still an NEC violation.

You have lights and receptacles on the same MWBC.

In this case you would have two branch circuits so no violation. :)

590.4(D) Receptacles.
(1) All Receptacles. All receptacles shall be of the ground-
ing type. Unless installed in a continuous metal raceway
that qualifies as an equipment grounding conductor in ac-
cordance with 250.118 or a continuous metal-covered cable
that qualifies as an equipment grounding conductor in ac-
cordance with 250.118, all branch circuits shall include a
separate equipment grounding conductor, and all recep-
tacles shall be electrically connected to the equipment
grounding conductor(s). Receptacles on construction sites
shall not be installed on any branch circuit that supplies
temporary lighting
.

Also much of 590.4 is written to allow this type of temp lighting. Sections (B) and (C) mention NM cable and section (G) permits splices without the need for boxes.
 

iwire

Moderator
Staff member
Location
Massachusetts
What would be the reasoning for not allowing such an installation ?

The outlets being overloaded causing the lights to go out.

A two pole GFCI supplying the MWBC causing the lights to go out.

Servicing the receptacle circuit will put the lights out, remember handle tie required for MWBC.
 
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kwired

Electron manager
Location
NE Nebraska
Are those incandescent bulbs exempt from the ban?
I would imagine that left handed LEDs and CFLs may not be available.

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My guess would be they are not included in the ban, it is reasonably specific on what lamp types are included, and is generally standard edison base lamps or other specific types, this would be a specialty base IMO and would need that specific base included in the wording before it is covered by what is banned, and it is not really a ban as much as a requirement to make the mentioned units meet a certain performance level, there are some lamps out there that were redesigned and do meet the new performance levels. But they also usually are expensive enough that consideration of CFL or LED technology is well worth looking into. I wanted some replacements for 75PAR30 lamps, they have some that are rated like 53 watts or so that are supposed to be pretty close in performance to the old 75 watt, but they wanted about $12 per lamp:eek:. We ended up finding some traditional 75 watt lamps online for that time around, but I think that LED's and CFL's will start to take over if you need to pay $12 a lamp and lamp life is not really changed much.
 

kwired

Electron manager
Location
NE Nebraska
osha standard 1926.56 (a) deals with construction lighting , 5 foot_candles at any given spot

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Next comes where and when does it apply?

Who provides light for the guys installing the temporary lighting?:)

They need safety also.
 

iwire

Moderator
Staff member
Location
Massachusetts
Kitchen counter requires two branch circuits, run one 12-3. Equals two branch circuits. Temp light/power same thing. :)

Not the same thing. SABC can share a circuit or not. Temp power cannot be part of a branch circuit with temp lights. I understand you have done this a long time but IMO using Charlies Rule it is in fact an NEC violation. :)




Per the Article 100 definition of MWBC it is a 'a circuit' not 'circuits' Maybe the supplying the SABC is also a violation as written. :p
 

GoldDigger

Moderator
Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
It may well be a violation as written. But the reason for two SABC circuits is capacity while the temp wiring issue involves independence.

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kwired

Electron manager
Location
NE Nebraska
Kitchen counter requires two branch circuits, run one 12-3. Equals two branch circuits. Temp light/power same thing. :)
Something to back your statement up:
210.4(A)

(A) General. Branch circuits recognized by this article shall be permitted as multiwire circuits. A multiwire circuit shall be permitted to be considered as multiple circuits. All conductors of a multiwire branch circuit shall originate from the same panelboard or similar distribution equipment.

However 590.4(D)(1) does say "Receptacles on construction sites shall not be installed on any branch circuit that supplies temporary lighting." but does not clarify if that means a multiwire branch circuit is included in that intention. I kind of get the feeling the intent is that a tripped breaker because of too many power tools running at once, or something similar doesn't leave people in the dark, but it really does not clarify that intention if that is why we have that rule. There is nothing there that specifically overrides what is mentioned in 210.4(A).
 
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