Large price jump 2" -> 2 1/2" PVC

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4/0-4/0-4/0-2/0 "Wakeforest" is common around here, but is primarily used as service conductor for three phase.

Cable marketed as Mobile home feeder cable likely is 4/0-4/0-2/0-4.
 
Little Bill said:
I've never seen a mobile home feeder cable with a 2/0 EGC.
For sure no box stores around here carry that. Why would you need that size? A #4 is all that is required for a 200A service/feeder.
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www.menards.com

4/0-4/0-4/0-2/0 Aluminum Mobile Home Feeder Cable (per Foot)

This 4/0-4/0-4/0-2/0 aluminum mobile home feeder cable is used to connect the meter base to the distribution panel. Used to connect the meter base to the distribution panel.
www.menards.com www.menards.com

www.homedepot.com

Southwire 500 ft. 4/0-4/0-4/0-2/0 Black Stranded AL MHF USE-2 Cable 28714401 - The Home Depot

Visit the Home Depot to buy Southwire 500 ft. Service Entry MHF Cable 28714401
www.homedepot.com

nassaunationalcable.com

4/0-4/0-4/0-2/0 Aluminum Mobile Home Feeder Cable

4/0-4/0-4/0-2/0 Aluminum Mobile Home Feeder Cable: 200 Amps, 600V, NEC-approved, UL-rated XLP insulation. Ideal for mobile homes. Order today!
nassaunationalcable.com nassaunationalcable.com

I too have wondered why such a large EGC is used, never really could come up with a good answer, but there it is.

Maybe someone with a good contact inside Southwire could get an answer that question?
 
Southwire's website says "Southwire® mobile home feeder consists of four quadruplexed type RHH or RHW-2 or USE-2 Alumaflex® Brand AA-8000 series aluminum alloy compacted conductors. The cable contains 2 triple-extruded phase conductors, a white striped neutral conductor and a green grounding conductor to eliminate the need for field marking per the National Electrical Code. The insulation is sunlight resistant."

They offer both 4/0-4/0-4/0-2/0 and 4/0-4/0-2/0-4 but don't suggest which is applicable when.


I'm not educated to know; out of my ex-electrical functions.
 
VirutalElectrician said:
Looking at parts for 2 1/2" PVC items, why is there such a large price jump from 2" to 2.5" fittings?
from 1/2 to 2, there's normal price increments, but 2 to 2 1/2 they are huge...

eg:
Sealing rings: 2" $2.00 2.5" $10.00
PVC LB: 2" $14.00 2.5" $44.00
PVC T" 2" $20.00 2.5" $84.00
PVC Sched40 conduit: 2" $26 2.5" $49

So to go from 2" to 2 1/2" there's a 2x to 5x price premium....Then to go 3" there's only a slight increment again from 2 1/2".
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Did a Google search and schedule 40 2 1/2" PVC has a wall thickness of 0.203" verses only 0.154" for wall thickness and 1.07 pounds per foot vs only 0.68 pounds for 2". So the 2 1/2" schedule 40 PVC contains 157% more then the 2" but does not explain why the 2 1/2" PVC cost 188% more then 2". Reminds me of the first time that I purchased a case of 2' & 4' fluorescent lamps that were identical in manufacturer & color temperature. The 2' lamps probably cost 40% more then the 4' lamps.
 
There is many options available for multiplexed conductor assemblies. What your local supplier may have ready access to can vary though. Often depends on what has been in demand.

The 4/0, 4/0, 4/0, 2/0 that is common around here is mostly used for three phase service conductor applications, a lot of it for long runs on farming applications. Most of it is also only straight URD rated and therefore not code compliant to use inside buildings.

About the only commonly stocked items that have multiple conductor ratings and can be used inside around here is triplexed assemblies and mostly in common sizes used for 60 to 200 amp supply like 4-4-4, 2-2-4, 1/0-1/0-2, 2/0-2/0-1, 4/0-4/0-2/0 and 250-250-3/0, the smaller conductor usually having white striping or even solid white. White is often more of a yellow, though I don't know why. The intent was it to be used for neutral. Some inspectors insist we identify it with white or gray marking some just let it go as is.
 
petersonra said:
I don't know if it's still true but we were told at one time not to use number three wire because number two was actually cheaper and number three was not stocked by our local distributors.

I suspect the ampacity of number 3 makes it such that it is an uncommon choice which may explain the pricing and availability issue.

I have no doubt that you can get number 3 if you really want it but if I recall correctly we had like a hundred foot spool of number 3 somebody bought and there is like 50 ft of it left and it took 5 years to use it up.
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Never had trouble getting #3, and it's a very very common size as it's good for 100A feeders.
 
electrofelon said:
Never had trouble getting #3, and it's a very very common size as it's good for 100A feeders.
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We don't have all that many 100 amp feeders inside of control panels. It just turns out that we use very little of it so the VP in charge of such things did not want it purchased just to have the excess sit around for many years before getting used up.

I am pretty sure there is some milspec Teflon insulated wire left over from projects I did twenty plus years ago. We use a fair amount of #18 because I just standardized on it for most of the uses we would need tef insulated wire for, but I bet there is some smaller sizes still laying around waiting to get used.
 
garbo said:
Did a Google search and schedule 40 2 1/2" PVC has a wall thickness of 0.203" verses only 0.154" for wall thickness and 1.07 pounds per foot vs only 0.68 pounds for 2". So the 2 1/2" schedule 40 PVC contains 157% more then the 2" but does not explain why the 2 1/2" PVC cost 188% more then 2". Reminds me of the first time that I purchased a case of 2' & 4' fluorescent lamps that were identical in manufacturer & color temperature. The 2' lamps probably cost 40% more then the 4' lamps.
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Interesting math. Thanks for that. In addition, when making similar products whether it be 1/2" vs 2 1/2" PVC or 2' or 4' lamps, there's a equivalent fixed cost to making that product, no matter what the size...ie, time on the machine to make it, box it, toss it in a truck, unload it, put it on the shelf, etc. Therefore you'd think the cost per unit would actually go down per size unit. Ie, 4' should be less than twice of a 2' lamp.
 
I was surprised this hasn't been addressed. It isn't just PVC. It is All conduit types. I suspect it carries across to plumbing as well. Our installation costs go up significantly at that break point as well. I am pretty sure the material cost is mostly due to the aforementioned mass production. It is very rare to see anything larger than 2" in residential. As others mentioned about avoiding, residential would most certainly avoid over 2" Always run parallel feeders over 200 amps, for example. So there is bound to be a much higher demand under 2". Add to that you need an entire new catalog of tools for products over 2" from threaders, to benders to hot boxes. Set up, transportation, maintenance costs, handling, training, difficulty of use and other factors all take a big step between 2" and 2 1/2".
 
Strathead said:
I was surprised this hasn't been addressed. It isn't just PVC. It is All conduit types. I suspect it carries across to plumbing as well. Our installation costs go up significantly at that break point as well. I am pretty sure the material cost is mostly due to the aforementioned mass production. It is very rare to see anything larger than 2" in residential. As others mentioned about avoiding, residential would most certainly avoid over 2" Always run parallel feeders over 200 amps, for example. So there is bound to be a much higher demand under 2". Add to that you need an entire new catalog of tools for products over 2" from threaders, to benders to hot boxes. Set up, transportation, maintenance costs, handling, training, difficulty of use and other factors all take a big step between 2" and 2 1/2".
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The practicality of working with it within a small space is limited also so it's understandable that it be a line in the sand just like 1 1/4 vs 1 1/2
 
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