Pottery Kiln and metalworking

I just signed my name to enough copper wire, from size 6 to 14, to wire an entire 25,000 sq ft machine shop filled with 50 amp CNC lathes, overhead lighting and 110vt outlets

Im glad..really really glad..its the customer paying for all of that...fuckmerunning copper is out of sight...

When the counter guy handed me the paperwork..I nearly had a stroke.

Gunner

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Reply to
Gunner
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look into open wire trays.. they cut the wire size for the same amps quite a bit. You use the free space current carrying capacity. With copper up that high the aluminum trays become cheap.

John

Reply to
john

Good idea, I will check into this further.

Mike

Reply to
KyMike

Red hot coils are easy to achieve, at least locally hot, with a gas torch, I wouldn't have thought the vendor intended you to work on live hot elements. It's also fairly easy to make your own elements from wire and the wire is not likely to be expensive in the quantity you require. A number of vendors may also sell you ready wound elements to your requirement, first place to check would be the original maker if still in business. Search for potters supplies or glass.

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would be one that comes to mind in the US for wound elements.

Reply to
David Billington

looks like we may bring back aluminium house wire yet. Gerry :-)} London, Canada

Reply to
Gerald Miller

Cable Tray makes building the shop a lot easier because you don't have to run and secure conduit everywhere, and it makes Moves and Changes vastly easier and quicker - but you really can't reduce the wire sizes too much before you get into trouble from voltage drop.

And with AL wire you have to go larger, and for long runs a lot larger to get the same ampacity and voltage drop targets. AL wire is still cheaper than CU for the same ampacity, but the potential connection troubles make it not worth the extra effort.

Stick with Copper for the branch circuits. If you want to use AL Wire, use it for the large feeder cables from the Main Panels to the remotely located sub-panels near the equipment (that will never move), and short runs of Copper BX in cable tray to the equipment.

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Reply to
Bruce L. Bergman

GACK!!!!!!!!!!!

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Reply to
Gunner

Is it kosher to leave the top cover off 4" gutter, or does it have to be closed back up when put in service? Ive got 180 feet of it hanging at the moment, waiting for the 800 amp service to go in.

Gunner

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Reply to
Gunner

Not an electrician, but I'd close it, especially in a machine shop. I guess most chips are caught by the enclosures plus coolant, but you wouldn't want even dust accumulating too much on electrical cables. Cable tray allows stuff to drop through that isn't laying directly on a cable.

Pete Keillor

Reply to
Pete Keillor

Its 12' off the floor.

Gunner

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Reply to
Gunner

cut your own out of a spool of nichrome wire. you can get this at mcmaster.

Reply to
charlie

OK, no chips. Dust will still collect over time, but depends on environment. I've used a lot of 6" duct with hinged lids and lay in flanges on research rigs because I can mount switchgear on it and subdivide it into signal and power with a trough divider. In larger pilot plants, we usually go with cable tray.

Pete

Reply to
Pete Keillor

Yes, and your point is...? ;-)

You know better than that... Get a machine going good and taking a big bite, crap can spray everywhere - 12 feet is well within range.

Gutter with insulated wire inside IMNSHO /should/ be closed when it's energized and in service. Can't quote any Code rules that it must be every moment, but it's just common sense.

But there's no reason you can't leave it open if you are actively working and have more work to do inside within the next day or two. With the caveat that I'd turn off all the breakers to the machines fed from that gutter when it's left open and unattended overnight...

Just in case something decides to "go seriously wrong" there is a body around to call the Fire Department and try to put it out.

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Reply to
Bruce L. Bergman

Would a heating element out of an electric broiler or oven work?

John

Reply to
john

I lucked out many years ago on a govt auction. I got 4 pallets of the

4" x 5 ft hinged lid square D cable trough for 200 bucks. I have been using it over the years and now have about a half pallet left. It makes it much easier to tie in machines.

John

Reply to
john

Mice will eat it before the dust does that much. It gets sanded off from time to time. :-)

Martin

Mart> >

Reply to
Martin H. Eastburn

yes. it's roughly the same metal, although a different gauge. the coils of a kiln, oven, and toaster, are nichrome, with different alloying depending upon the top temperature that the heater is expected to reach. a pottery kiln will usually top out somewhere between 2100F and 2350F, depending upon it's wall thickness and type of elements. running at it's higher range shortens the life of both the elements and bricks.

note that after it's first heated, elements can be fragile. don't try to move them around too much in the brick slots without heating them with a propane torch. if one breaks, you can replace it, or even overlap them and fasten the ends together with some sort of metal cable connector, but i don't recommend that. as they heat up, they move. the connector can erode a hole through the bricks as they're really soft.

regards, charlie

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Reply to
charlie

Actually I think you will find that the elements in a pottery kiln are FeCrAl material such as Kanthal A1and not NiChrome, IIRC NiChrome will do upto about 1000C and FeCrAl such as Kanthal A1 to about 1350C.

The elements in ovens are typically about 8mm diameter and have an outer metal sheath surrounding a mineral insulation which surrounds the heating element, so the element is isolated from the sheath. They are available in that style in various max temps so I don't know what an oven element would max out at but that style of element is readily available cheaply in straight annealed form for custom bending with a max limit of about 800C. I know someone who is at the moment using these to heat her annealing oven for blown glass pieces.

Reply to
David Billington

thanks for the info

Reply to
charlie

Tell me about it! Brother building a house. (Me helping with elec. work.) We needed more Romex - sticker shock.

Reply to
MadDogR75

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