Home feeder

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Little Bill said:
1' of USE-2 cable (4 conductors) = 2.65
2' of THWN ({2} 1' conductors) = 2.88
then add on to that the cost of neutral and EGC would make it at least $4 per ft for (4) individual THWN conductors.
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Are you comparing aluminum to aluminum?

If so it looks to me like you are getting bent over on the THWN.
 
iwire said:
Are you comparing aluminum to aluminum?

If so it looks to me like you are getting bent over on the THWN.
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Not saying you can't get THWN in aluminum elsewhere - but is not stocked in supply houses around here. All they have for aluminum in single conductor or URD (or whatever you want to call the multiplex conductor assemblies) is USE, RHW, combination rating of USE/RHW, or XHHW. All the THHN/THWN conductors are all copper, but you will not find copper conductors in USE, RHW, or XHHW. I think it is just a supply/demand thing, if people started to ask enough for something not currently available it would get ordered and become stocked item.
 
From one of my suppliers online pricing site I can get 2-2-2-4 URD aluminum (most likely USE rated only and not for interior use) for $1.35 foot, #2 XHHW aluminum for $0.3733 foot (times four gets us a little higher then the quad but the quad did have one 4AWG instead of all #2, plus it can be run indoors. Common sizes they have in stock that are dual rated and can be indoors is usually 2/0 and 4/0 triplex and possibly a 1/0 or a 250 size most likely in triplex. Most other URD cables stocked are USE only and I'd say the bulk of them sold are for irrigation or other farm loads that either never end up inside or never end up inspected (or both).

#2 copper THHN/TWHN was $1.18 foot for a single conductor, the aluminum was about 31% of that - of course it is not same ampacity so more info needs factored into cost difference between copper and aluminum for a particular install.
 
Bob I think the reason it is cheaper as a cable is the same as why a 3' fluorescent tube cost more than a 4' tube. Supply demand and storing , shipping and handling must keep the cost down when compared to 4 reels
 
I would bet if you tried to get a cable like that for something other than 4/0 alum and #2 alum you would pay more than the individual conductors. These cables where for trailers at 100 or 200 amps
 
Esthy said:
Whoa, this is a cheap price for the 100. I will need 25' to supply the Mobile Home I was talking about in another post. Apparently this is new in the market. Will AHJ approved this in WA?[/QUOTE

If you are working in WA, then you need a copy of the electrical laws and rules, RCW-WAC
Download here:
http://www.lni.wa.gov/TradesLicensing/Electrical/LawRulePol/LawsRules/default.asp

If you don't subscribe to the electrical currents then at that LNI website find the page and subscribe. Watch out for the burial depth of the GEC - its not a WAC rule but is in the Electrical Currents.

Better yet take one of my RCW-WAC update classes :)
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My experience in central NY and Seattle area:

1. URD/MHF/etc are cheaper than single conductors XHHW. The difference between "4 wire URD" and "MHF" is a different combination of neutral and ground sizes.
2. THWN AL is rare, I have seen it only a few times except in large AL MC cable where it seems 50/50 between XHHW and THWN. This drives me crazy though as I use a ton of aluminum and THWN would be easier to pull.
3. I have never seen URD/USE that is not also RHH-2
 
iwire said:
Are you comparing aluminum to aluminum?

If so it looks to me like you are getting bent over on the THWN.
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No, only thing we can get (locally) in Al direct bury, is the USE-2. All the THWN is copper. That's why I said it was cheaper. I wasn't trying to mislead by comparing copper to Al, it's just what we have to choose from. Only Al we can get is the USE-2 (MH feeder) and SEU/SER cable.
 
Tom Baker, does your clases qualify for the continue education? Are you close to Seattle? I retired from another state and after 4 years inactive and getting in my wife nerves I opened the licenses here in WA but been inactive, old and cranky I need more education, specially that I am doing now Mobile Homes that I never did. Few years ago, publicly, I apolagized to you in this forum for some coment I did. Thanks to all the mentors here that keep many of us going.

BTW, just another MH, that we just took for maintenance, went on fire, some maintenance handyman tail the aluminum wires to copper in the wrong way and the fire started in a metal box that the aluminum ground was attached by a clip to the box and it arced.
 
My market is electrical continuing education and trainee basic classroom - been at it 19 years. I was the first chief moderator at this site.
All my classes are approved for electricians and trainees. We had the first two trainee classes approved in Washington in 2007.
We are in Bremerton. My next RCW/WAC is in Satop, at the old WHOOPs reactor site, May 30th, west of Olympia.
Tom
Master Electrician
 
Esthy said:
Sorry to ask, but where is Satop? I don't find it.
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Near Elma, west of Olympia. In the 1980s Elma had the largest high school in the state due to work on the Whoops reactors 3 and 5.
you can just see the tops of the cooling towers from the highway...

I'll have a class in Bremeton this fall.
 
kwired said:
I bet there is/has been a lot of local talk about that name:cool:
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It was the Washington Pubic Power Supply System. Set out to build 5 nuke plants. went belly up in about 85. largest public bond default in history,
http://www.satsop.com/aerial-of-satsop-sites.html
One of plants was 75% done and ready for fuel. Its a fascinating place, everything on this huge industrial scale. Its used quite a bit for security training in the tunnels and buildings...
 
I am more confused than a Chameleon in a bag of Skittles (I learned this today) 2-2-2-4 is for 90 amps, so, it is not good for the 100. Please, what is the appropriated and least expensive wiring for a mobile home underground in conduit (50') for 100 amps? Someone is donating $100.00 Home Depot card. Hope they have the one needed. Those MH are driving me nut.
 
Esthy said:
I am more confused than a Chameleon in a bag of Skittles (I learned this today) 2-2-2-4 is for 90 amps, so, it is not good for the 100. Please, what is the appropriated and least expensive wiring for a mobile home underground in conduit (50') for 100 amps? Someone is donating $100.00 Home Depot card. Hope they have the one needed. Those MH are driving me nut.
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Who is telling you not to use it at 100A? Your inspector?

The old TABLE 310.15(B) (7) says #2 is good for 100A for service conductors. 2014 code makes you do some math instead of using the table but the end result is usually the same.
 
2-2-2-4 Aluminum Quad Dyke Wire. This is the one that I was checking at Home Depot for $1.47 per foot, to use as a Service, 40' from the meter/disconnect to the Mobile Home inside panel in conduit (the inspector allowed to bypass a pedestal and going directly ...) but the "electrician" at HD stated that it if for 90 amps.

I am embarrassed to recognize that my mind at 72 is going downhill and I become more easily confuse. My apologies for this.
 
Esthy said:
2-2-2-4 Aluminum Quad Dyke Wire. This is the one that I was checking at Home Depot for $1.47 per foot, to use as a Service, 40' from the meter/disconnect to the Mobile Home inside panel in conduit (the inspector allowed to bypass a pedestal and going directly ...) but the "electrician" at HD stated that it if for 90 amps.

I am embarrassed to recognize that my mind at 72 is going downhill and I become more easily confuse. My apologies for this.
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Form the 2008 NEC
Table 310.16 75 Deg. C. shows an ampacity 0f 90 amps # 2 AWG Aluminum

This may very well be what the employee at HD was referring to.


Table 310.15(B)(6) Conductor Types and Sizes for 120/240-Volt, 3-Wire, Single-Phase Dwelling
Services and Feeders. Conductor Types RHH, RHW, RHW-2, THHN, THHW, THW, THW-2,
THWN, THWN-2, XHHW, XHHW-2, SE, USE, USE-2

For service or feeder rating has an allowance of 100 amps for 2AWG Aluminum
 
Esthy said:
2-2-2-4 Aluminum Quad Dyke Wire. This is the one that I was checking at Home Depot for $1.47 per foot, to use as a Service, 40' from the meter/disconnect to the Mobile Home inside panel in conduit (the inspector allowed to bypass a pedestal and going directly ...) but the "electrician" at HD stated that it if for 90 amps.

I am embarrassed to recognize that my mind at 72 is going downhill and I become more easily confuse. My apologies for this.
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Don't be embarrassed, you don't have to be 72 to get confused!:D

The wire you show is fine for the service of 100A.
First, not all employees at the box stores (Home Depot, Lowes, etc) who claim to be "electricians" are. Or they may be in a sense but not certainly qualified enough to be giving advise on all electrical requirements. Second, you need to look things up to verify and not take what they say as factual.

But as David pointed out, the guy at HD was right in that the #2 al wire is only rated at 90A from the ampacity table. But using the table for dwelling units there is an allowance for using a smaller wire provided the wire (service or feeder) carries the entire load of the dwelling. That wire you show is what I was talking about in another post. It is what we call 100A mobile home wire and is fine for what you are doing.
 
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