# Pre Fab Ideas



## 5volts (Jan 11, 2008)

plug and play?


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## 3rdgeneration (Jan 12, 2009)

Huh?


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## 5volts (Jan 11, 2008)

ok............


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## Megawatts (Jan 12, 2009)

*Pre-Fab*

I wouldn't. I run the conduit, place 1900 boxes, and run mc from theirto the devices. Whats he have plane for the equipment? Bologna Cable or conduit?


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## 3rdgeneration (Jan 12, 2009)

Megawatts said:


> I wouldn't. I run the conduit, place 1900 boxes, and run mc from theirto the devices. Whats he have plane for the equipment? Bologna Cable or conduit?


Conduit for equipment.


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## 5volts (Jan 11, 2008)

http://images.google.com/imgres?imgurl=http://www.finelite.com/uploads/pics/TCC_PlugAndPlay2sm_fix.jpg&imgrefurl=http://www.finelite.com/products/icls-installing&usg=__8Ov5H1Z3H9c-FqgTYfqdJ35FSyg=&h=298&w=358&sz=21&hl=en&start=34&um=1&tbnid=Qyyhy0bd9cVQ_M:&tbnh=101&tbnw=121&prev=/images%3Fq%3Dplug%2Band%2Bplay%26start%3D20%26ndsp%3D20%26um%3D1%26hl%3Den%26safe%3Doff%26rlz%3D1T4SUNA_enUS237US237%26sa%3DN............


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## Megawatts (Jan 12, 2009)

*Pre-Fabs*



3rdgeneration said:


> Conduit for equipment.


If it was me. I do it all in conduit then use the mc to feed the devices. Greenfield for equiment or seal tight. Depending on the app.

Your going to have a lot $$$ in mc. 
The lighting I like the quick connects also.


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## 3rdgeneration (Jan 12, 2009)

Megawatts said:


> If it was me. I do it all in conduit then use the mc to feed the devices. Greenfield for equiment or seal tight. Depending on the app.
> 
> Your going to have a lot $$$ in mc.
> The lighting I like the quick connects also.


We are wanting to prefab as much of the job as possible because the project is prevailing wage and we will save quite a bit by doing it in the shop where the prevailing wage rules will not apply. Unless someone tells me different I cannot see how it would be cheaper to use EMT on the site as opposed to M/C cable being prefabbed in the shop.

The quick connects are a good idea, unfortunately the specs don't allow it.


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## Kletis (Jan 18, 2008)

One thing that I would say is remember that if you pre-fab everything, they may change their framing a little bit from room to room based on the whole structure. Make sure that you won't need 4' longer whips in a few rooms due to a beam you have to go around or something like that. 

Your idea could work very well, but if it does not work right it will just be a huge waste of time. Make sure that you look at the whole scope before pre-fabbing them all.

Take it for what its worth.....


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## John Valdes (May 17, 2007)

I like your idea. When I was doing commercial high rise buildings we prefabbed in the shop.
We were using EMT though. All slab stubs, goosenecks, taped boxes with connectors installed ect....
Not real sure how to go about it with MC, but I'm sure you guys can figure it out.
We relied on prefabbing when every space was identicle.


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## Bkessler (Feb 14, 2007)

After wiring a couple, you can have all the mc pre whipped with connectors, and numbered with duct tape, all the boxes with the ground screw and pigtail and mudring installed, the k.o's k.o'd. You can have all fixtures pre assembled and delivered. 
I would number each box whether it is a switchbox or a plug and have the ends of each MC cable that go into that box with the same number, Any swithchlegs can be labeled with box number plus an additional mark to indicate swithching. So each unit would have a rough package with all the numbered boxes , and runs of mc lableled wih connectors and a number on each end.


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## spoon (Dec 9, 2008)

Ain't the price of MC down now-a-days? Talk with the supply house and see if they can cut you a deal if you buy 20,000ft. (or whatever you need). They'd probably work something out with you. I say on the first day or two of the job, set separate two-man teams in a dorm room. Give 'em each a 1000ft. spool of MC, a set of plans, and tell them to get crackin. At the same time, have a couple guys run through and box the whole place. After the first day or two, assuming all rooms are identical, you're teams will not even need plans and they'll just be on autopilot.


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## 3rdgeneration (Jan 12, 2009)

spoon said:


> Ain't the price of MC down now-a-days? Talk with the supply house and see if they can cut you a deal if you buy 20,000ft. (or whatever you need). They'd probably work something out with you. I say on the first day or two of the job, set separate two-man teams in a dorm room. Give 'em each a 1000ft. spool of MC, a set of plans, and tell them to get crackin. At the same time, have a couple guys run through and box the whole place. After the first day or two, assuming all rooms are identical, you're teams will not even need plans and they'll just be on autopilot.


 
Buying wire at a set cost is our plan. We do that all the time because with wire prices fluctuating like it does we prefer to buy ahead of time and get locked in.

The whole goal of prefabbing is not having to pay the prevailing wage scale. I would rather have the workers in our warehouse putting the junction boxes with devices on the M/C cable as opposed to doing it in the field where it will cost me easily twice as much in labor. The guys in the field can still do the autopilot scanario but they would do so with the vast majority of the leg work done in the warehouse at a much cheaper rate.


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## Trimix-leccy (Dec 4, 2007)

UK here!
Having done similar a few times it makes life much easier if as well as numbering with duct tape you also use different colours of tape. eg say you have numbers 1 to 100. 1-10 = red 11-20 = orange etc etc etc. It is a lot easier to spot the colour and then narrow it down to the number than have to go through all 100+ cables...been there, done that:thumbsup:


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## spoon (Dec 9, 2008)

3rdgeneration said:


> The whole goal of prefabbing is not having to pay the prevailing wage scale. I would rather have the workers in our warehouse putting the junction boxes with devices on the M/C cable as opposed to doing it in the field where it will cost me easily twice as much in labor. The guys in the field can still do the autopilot scanario but they would do so with the vast majority of the leg work done in the warehouse at a much cheaper rate.


You crafty fellow, you. Are the ceilings hard-lid? If not, have the device boxes prefabbed with MC whips (various lengths). The 'auto pilot' crew can install a couple junction boxes in the ceiling, and just run the device whips up to the J-boxes. Is that what you were thinking of doing, in your first post?


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## 3rdgeneration (Jan 12, 2009)

spoon said:


> Is that what you were thinking of doing, in your first post?


It is a drywall ceiling so for lighting we planned on just cutting a M/C feed long enough with a Junction box attached to it down to the light switch. The light switch will already be installed in the shop.


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## Megawatts (Jan 12, 2009)

3rdgeneration said:


> It is a drywall ceiling so for lighting we planned on just cutting a M/C feed long enough with a Junction box attached to it down to the light switch. The light switch will already be installed in the shop.


Are you a union shop?


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## BDB (Jul 9, 2008)

3rdgeneration said:


> The whole goal of prefabbing is not having to pay the prevailing wage scale. I would rather have the workers in our warehouse putting the junction boxes with devices on the M/C cable as opposed to doing it in the field where it will cost me easily twice as much in labor.


You better check on how the prevailing wage thing works. On all the PWS jobs I have done ( and we have done a ton) it does not matter where you prefab anything it is still for a PWS job, therefore PWS is in effect.


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## nickthegr81 (Feb 17, 2009)

my company is trying this same thing for the same reason, to save money on the PW. we are new to the pre fab life. we are doing the exact same scenario with the mc cable. a studbox with device installed on one end and stripped wires on the other. the lengths of mc are supposed to be a little long and all we will do is roll up and strap extra in the wall. devices are also coved with some metal cover that fits on the mudring device holes so they wont get painted over, however i dont know if the rockers are going to like it too much as it will be harder for them but...whatever. we are also using the quick snap in type connectors for the mc which is not something we ever do. also using wagos instead of wirenuts. the job is not done yet so i really dont have an opinion on whether it is faster or not but ,like engineers always think, it works good on paper. i dont like the fact that i feel like my company (who says they only take PW jobs for the employee to make a little extra) is screwing us out of the extra money.


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## gilbequick (Oct 6, 2007)

It may seem like they're screwing you out of money, but they did get the job therefore you got the work. Either way, you're making at least your normal rate and then some more sometimes.


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## Jeff000 (Jun 18, 2008)

Steel stud building? 
I can tell you one thing if its steel stud, MC only pulls through the stud one way, and its been my experiance that its 10x easier to pull off a real compared to pulling a coil of wire. 
Where I work they tried prefabbing, raced two identical suits, one had everything prefabbed, the other had nothing prefabbed. Both suits were marked out already. 
The prefab suit took ~10% longer and had huge amounts of waste wire. 
Wire might be getting cheap, but over 400 units having 10% more waste wire from prefab you're talking enough wasted wire to do 40 more suits. 
We have a stick marked with the hieghts of all devices, and just send one guy o the floor above to mark out the whole floor, really doesn't take long at all. And just set up with a wire rack and get er done.


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## hayan453 (Jan 22, 2009)

MC can be pulled through metal studs easier with a plastic bushing.. saves alot of time :thumbsup: On the high rises i've been on we ran PVC in the slab first, stub ups for the home runs, taped boxes in the walls for recepticles, and ceiling for lights and smokes.. ENT the home runs from the stub ups to the panel etc.. and MC the rest.. There is always something that changes.. so i wouldn't KO the boxes to pre fab, just install the ground tails.. we always have different crews doing different things... one crew to layout and screw boxes and another to pipe, run MC, pull wire, and splice..


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## calimurray (Apr 29, 2007)

when I was in California everything was mc they even ran 3/4" flex on racks for home runs.

we usually ran a bunch of 3/4" emt h.r.s to j boxes and then ran mc to all devices. I tell ya one thing you can rough out a big project pretty damn fast with mc and only have to pull your circuits to splice boxes later. we were installing 7000 ft of mc a day between two guys, and the caddy straps we used were so quick and easy. also we used Arlington snap in mc connectors which were a breeze.Thats roughed , spliced, strapped, grounded and rung.

they have 12-4 conductors in all 3 phase colors.


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## hayan453 (Jan 22, 2009)

yeah calimurray thats pretty much how we do it here.. and the 12/4 is great for travelers and a single ckt.. who needs pipe :thumbsup:


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## william1978 (Sep 21, 2008)

hayan453 said:


> who needs pipe :thumbsup:


 You must be new school because I hardly ever hear this.:no:


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## hayan453 (Jan 22, 2009)

Haha william1978 no i just do alot of commercial high rises... we use pipe in the slab but we rough in using alot of MC and smurf..


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