Anyone have a standard for when they run different types of conduit in there factory

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derelectric

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Hello,
I'm in the process of setting a standard in our manufacturing plant on when to use different types of conduit. (Emt, Intermediate, Rigid, sealtite etc.) Have all differnt electrical skill levels in the plant. So I want to set a standard to keep everyone on the same page. I know we will follow the NEC. Anyone have a standard they use in their plant?

Thanks
Derelectric
 
The plant I often work at is all rigid except for concealed conduit in office spaces, lunch rooms and similar locations.
 
When I was in the plant we revised the conduit standards - down.

Rigid only when really necessary at floor level, IMC above whenever possible

IMC preferred in production areas in general

Aluminum where appropriate

EMT in offices, corridors, stud walls, etc.


The olde standard of RMC everywhere was overkill and very costly!

I also convinced them to stop showing conduit runs on power plans. Construction generally routed them different anyway!


RC
 
derelectric said:
What do you do about machines that move around? They want to use SJ cord as drop cords to a rec.
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Frequent moving or interchange is good reason to use flexible cord, usually is a good idea to install in a way that limits excessive length though. The type of flexible cord may be subject to further scrutinizing though. Plain SJ is not going to handle the kind of abuse that some other types may be able to take.

Expected physical abuse is something that needs consideration in your overall standard in question here. Even RMC/IMC don't do very well in areas where there is mobile heavy equipment in use, but will still last longer than most anything else, the key is installing them in areas not so likely to be disrupted, though some equipment operators manage to find anything you never imagined they could find with the heavy equipment. Then you have wash down areas or corrosive areas in some places where you will need either PVC, PVC coated rigid, or even stainless rigid or else the environment may compromise the raceway before physical abuse gets to it.
 
derelectric said:
What do you do about machines that move around? They want to use SJ cord as drop cords to a rec.
Click to expand...

One of the plants I work in has several smaller machines mostly 3 ph 30 amp max and 120v drops for convienience outlets.
The engineer designed a distribution set up with a unistrut trapeze and a 6x6 wireway.

We built a unistrut trapeze open end up,where the 2 long runners 60' long ran east and west. then put full 10' cross pieces every
5' running north and south to tie the east and west runners together. The 6x6 gutter ran east and west in the center of the trapeze fastened to the crosspieces with bolts and springnuts. The gutter was fed from a LV 120/208V and a HV 480v panel to get the circuits needed to the gutter for distribution. Wherever there was a machine drop, we would take a 6' piece of 3/4" emt with a short
90d bend on the end compression connector into the gutter and strut strapped to the long runner. On the end of the 90d bend
we installed a 4 square box with a blank cover and brought the cord out of the bottom of the 4 square then back to a kellem grip hanging from the long runner down to the machine or twistlock or whatever. What we did do instead of bringing the circuits directly to the 4 square boxes at the machine location was to chase nipple 4 square boxes face down up into the bottom of the gutter every 4'.
That way the circuits remained in those 4 square boxes with the lid labeled and the gutter was just used as a raceway so there werent an overload of splices in the gutter,, the junction was made in the 4 squares nippled into the bottom of the gutter and kept it very clean.

Otherwise Rigid anywhere outside, on the roof or in the classified areas, emt inside with compression fittings only, black for all 480v wiring, Red for all 120v wiring excluding neutrals and Blue for all 24v control wiring.
 
jap said:
One of the plants I work in has several smaller machines mostly 3 ph 30 amp max and 120v drops for convienience outlets.
The engineer designed a distribution set up with a unistrut trapeze and a 6x6 wireway.

We built a unistrut trapeze open end up,where the 2 long runners 60' long ran east and west. then put full 10' cross pieces every
5' running north and south to tie the east and west runners together. The 6x6 gutter ran east and west in the center of the trapeze fastened to the crosspieces with bolts and springnuts. The gutter was fed from a LV 120/208V and a HV 480v panel to get the circuits needed to the gutter for distribution. Wherever there was a machine drop, we would take a 6' piece of 3/4" emt with a short
90d bend on the end compression connector into the gutter and strut strapped to the long runner. On the end of the 90d bend
we installed a 4 square box with a blank cover and brought the cord out of the bottom of the 4 square then back to a kellem grip hanging from the long runner down to the machine or twistlock or whatever. What we did do instead of bringing the circuits directly to the 4 square boxes at the machine location was to chase nipple 4 square boxes face down up into the bottom of the gutter every 4'.
That way the circuits remained in those 4 square boxes with the lid labeled and the gutter was just used as a raceway so there werent an overload of splices in the gutter,, the junction was made in the 4 squares nippled into the bottom of the gutter and kept it very clean.

Otherwise Rigid anywhere outside, on the roof or in the classified areas, emt inside with compression fittings only, black for all 480v wiring, Red for all 120v wiring excluding neutrals and Blue for all 24v control wiring.
Click to expand...
If you are in a plant that does food processing or has other sanitary needs, you don't want all that equipment there to catch things. The less electrical and mechanical items there are exposed, the easier sanitation becomes. First it is that much more for production people to have to keep cleaned, and second whatever does accumulate there is subject to contaminating product should it fall for any reason while production is going on. My point - every industry has different challenges and there is no one solution fits all for this kind of topic.
 
kwired said:
If you are in a plant that does food processing or has other sanitary needs, you don't want all that equipment there to catch things. The less electrical and mechanical items there are exposed, the easier sanitation becomes. First it is that much more for production people to have to keep cleaned, and second whatever does accumulate there is subject to contaminating product should it fall for any reason while production is going on. My point - every industry has different challenges and there is no one solution fits all for this kind of topic.
Click to expand...

So why are your responding to my 2 cents worth instead of to the OP's?

I was just giving an example of a different type of installation methods which i thought was what he was curious about and that just happens to be a small example of the way it is in this particular facility.
 
If you want to hear about how it is in a food processing plant I can fill you in on that also, but i thought it'd be rather lengthy to cover the installations in every area I've ever worked in.
 
jap said:
So why are your responding to my 2 cents worth instead of to the OP's?

I was just giving an example of a different type of installation methods which i thought was what he was curious about and that just happens to be a small example of the way it is in this particular facility.
Click to expand...
OP probably read it as well:p
I wasn't necessarily responding specifically to you as much as I was responding to the content of the thread as it comes up.
 
Most of my contracting years were spent in industrial. Way too many variables to suggest without more detail. Likelihood of physical damage, environmental, etc. all play a role. "SJ" was seldom used as type "SO" held up far better.
What type of industry are you looking at ?
 
derelectric said:
What do you do about machines that move around? They want to use SJ cord as drop cords to a rec.
Click to expand...


We have cable drops for pump carts and some smaller moveable equipment. I don't know about SJ
cable. We use SO type cable, but in the past I have used buss drop cable, made for this application.
The main thing is proper strain relief for the cable.
 
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