Service Drop Cable

I meant, #2 X 3 conductors, 2 hots and 1 neutral. Plus the bare ground of course.

Reply to
Anthony Guzzi
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I meant triplex wire.

Sorry for the confusion.

Reply to
SQLit

Service drop is the utility overhead conductor. A service lateral would be the utility side of an underground service. They are also referred to service conductors. Service ENTRANCE conductors are the customerr side of the "service point" which is usually at the service head but it may be in the meter base with an underground service.

Reply to
gfretwell

So when an old timer comes in and says he wants "knot knot" (or however it is spelled), you know were to send him? :)

I am pretty sure on this side of the coast it is grey at HD. Might just be a sourcing thing, as they are heavy and they might have local sources for it.

I know what you mean. Some customers tie up the damn clerks for a 1/2 hour asking them to design the whole circuit for them. All the while I am sitting there waiting to get some wire off the rack. Another reason I do not bother there.

Reply to
Chris

pretty hard on the guy he has the right answers for the wrong reasons dont ya think better advice than alot in this newsgroup

Reply to
PCK

True, and no offense to the guy. Just a lot of bad experiences with HD and anything electrical.

I can at least give him an A for effort.

Reply to
Chris

Hei, kissi

For your infor, in my country there are very rare to hear that domestic loads may needs up to 200A unless for small scale industries. If you need to do so, you need to have main switch board which is rated

200A c/w all protected equipments include CT (currents transformer). Usually, incoming cable if underground 1x 4C - 35sqmm/pvc/swa/pvc Cu armour cable. If overhead by using ABC (ariel bundle cable)- 4x 1C-35sqmm AL may up to 33KV.

you can also calculate the cable saiz and voltage drop by taking some assumption factors or more fast referred to electrical standard book.

tks

magic

Reply to
magic

Thu, Sep 15, 2005, 4:38am (EDT-3) From: aladin snipped-for-privacy@yahoo.com (magic) Kissi Asiedu wrote: What size and type of cable would the electric company use as service drop for a house with a load of 200Amps. What book or web site is recommendable of this topic. I'll like to learn more about load calculations. Thanks

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Hei, kissi For your infor, in my country there are very rare to hear that domestic loads may needs up to 200A unless for small scale industries. Snip< tks magic

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Here in The US this is not a consideration for anyone but the Utility.

The Service Entrance Cables which is what He's asking about should be installed by a Licensed Electrician and and as described by Mr. Perry.

The Utiltiy Part will Not be Installed or connected until The Service Entrance Cabling and Electrical System (Meter Panel/Disconnect, etc.) is in place & Duely Inspected.

If this is a Trailer Park; I'd wire a distribution panel with # 6 or 8 back to the Meter Pan. and the service entrance cable from the Meter Pan to the Weather Head # 2 (I hate sheathed Cable for this & Prefer Proper Piping be employed) for the Service Drop, which will probably be air run of twisted 2/O from the Utility Pole. & I'd Make sure I'm getting a

200Amp MeterPanel for The Utilities Plug In, if that is what is required.

There are a Lot More considerations to this installation than should be explained here..... given the variety of circumstances of any particular installation & it's location.

Roy Q.T. Urban Technician [I don't make em, I just fix em]

Reply to
Roy Q.T.

Gad!

Why not? (I understand not selling, say, #6 and small Al wire. But why no the BIG stuff?

Reply to
John Gilmer

I don't really know the exact reasons. However I thought that Aluminum wire was not legal in the US.

It would be nice if we had the large ones in Al, those spools of copper #2 weigh like 500 pounds!

I suspect one other reason might be that it would be easy for the customers to become confused by the different types of wire, and choose the wrong one.

Reply to
Anthony Guzzi

The only aluminum wire that is not legal for branch circuits and feeders in the US is the old 1350 alloy. The new AA8000 alloys are perfectly legal, and safe although the bad reputation still exists.

Reply to
gfretwell

Hmm, didn't know that. Ok, so is this 1350 alloy just a different formulation of aluminum for the wire? The AA8000 being the newer formulation and the 1350 being the fomulation used in the 50s, 60s or

70s or whatever?

For this new stuff, the AA8000, would you use the same gauge as you would with copper in any situation? Or would you use one gauge thicker than you would with copper?

I know what a branch circuit is, but what is a feeder?

Reply to
Anthony Guzzi

You still have to follow the aluminum ampacity table, which is generally one size larger but once you get to 70a (4ga copper) the aluminum slips another size.

The old alloy was originally designed for overhead spans and breaks pretty easily if it is bent sharply. The newer alloy is designed to be harder to break from bending and the expansion characteristic is more in tune with the screws used in Cu/Al terminals. Used with CO/ALr devices it would probably be OK but nobody will actually try it. In larger sizes, using set screw terminals it has really never had problems. Since most lugs these days are an aluminum alloy it actually has a better expansion characteristic.

Old legends die hard tho.

Reply to
gfretwell

snipped-for-privacy@aol.com wrote: > The old alloy was originally designed for overhead spans and breaks

For 15 and 20A branch circuits, the current alloy aluminum expansion characteristics may have been substanitally fixed. But it has the same oxidization problem as the old aluminum wire. On small branch this would produce the same safety problems in wire nuts, if nowhere else.

Bud--

Reply to
Bud--

I suppose that is why they invented anyi-oxidants huh? Have you seen the Ideal 65 wirenut?

Reply to
gfretwell

A lot of information on aluminum wiring has been collected at

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also includes web links. Information below is derived from this site. The best of the links is
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is based on information derived from extensive tests at the Wright-Malta Corp.

IDEAL #65 TWISTER The Consumer Product Safety Commission (CPSC), reacting to fires caused by aluminum wiring connections, contracted with Wright-Malta Corp., an independent test laboratory, to do extensive testing. Some of this testing was done on the Ideal #65 Twister wire-nut. This wire nut appears to be a standard Ideal wire nut with antioxide paste inside. The testing found that the Ideal #65 was not better than other wire-nuts that were not listed for aluminum wire. (Information at

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"D"). In addition to failing, the Ideal plastic shell and included antioxide paste burned. (There is a multipage slide show of a presentation to the CPSC from the Wright-Malta lab at:
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includes pictures of the Ideal #65 burning.) As a result of the laboratory tests, the CPSC requested that UL change its test procedures to be more realistic. Ideal told the CPSC that "the Ideal #65 was not intended for use for [pigtailing retrofit], but only for such applications as connecting lighting fixtures and ceiling fans. Ideal committed to CPSC to change its advertising and instructional information accordingly, but did not follow through on that commitment."

WIRE-NUTS ON ALUMINUM WIRE The Wright-Malta Corp. tests found that because of surface oxide, there is poor initial wire-to-wire contact to aluminum wire(s). The steel spring in the wire-nut cuts through the oxide and makes contact, so initally about 60% of the current flows through the spring. Over time and use, the contact between the wires may be reduced, sometimes to zero. The contact from aluminum to spring may also be reduced so only a small part of the spring is carrying the current. However steel is not a good conductor. Tests found a 2 volt drop across the wire nut through the spring at 17 amps. This is only about 0.1 ohm resistance, but it is a 34 watt heater. At this current level the spring is red hot. In other tests, the spring is red hot at 12 amps. This destroys the insulation on the wires and the wire nut and can start a fire.

THE NEW ALUMINUM ALLOY WIRE HAS THE SAME OXIDE PROBLEM AS THE OLD WIRE.

The only fix recommended by the CPSC is the COPALUM compression sleeve that makes a cold weld to the wires.

Note that

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"C" and "A", gives a detailed procedure for using wire-nuts with aluminum wire. A critical part is applying antioxide paste to the stripped wire then abrading the wire to remove the oxide. Know anyone who does that, huh?

Bud--

Reply to
Bud--

I have seen (and purchased but not yet use) those "poke in" connectors. I don't even know if they are rated for Al. But you seem to be saying that the ONLY way to go for the "little stuff" is a hard crimp! Screws just aren't "gud enuf."

Should we start to worry about the "big stuff" used for electric stoves or from the meter to the service panel?

EMWTK

Reply to
John Gilmer

(I don't know what the "poke in conectors" are.)

The only method recommended by the Consumer Product Safety Commission is the COPALUM high pressure crimp system. The crimps replace all wire nuts and a copper wire is pigtailed out at devices. They specifically advise against using wire nuts. (But see paper below for a wire-nut use.)

Wire nuts, as well as connections to devices, have caused problems including fires. My understanding is the new alloy and CO/ALR devices solve the expansion problem but have the same oxide problems. Wire nuts with the new alloy should have the same oxide problem as before.

The best information I have seen is at

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is a paper based on information derived from extensive tests at the Wright-Malta Corp. for the CPSC. I covers a WIDE RANGE OF OPTIONS.

Anyone with an interest in aluminum wire 15 and 20 amp branch circuits you should look at the paper.

Paper highlights: - information on the options to reduce aluminum wiring risk - information on COPALUM crimp connections (mentioned above) - DETAILED PROCEDURE TO USE WIRE-NUTS WITH ALUMINUM WIRE to pigtail a copper wire or to replace existing wire-nuts, including brands to use - description of how wire-nuts fail; existing wire-nuts should be replaced - discussion of problems with Ideal #65 wire-nuts (the only UL listed wire-nut for aluminum) - how to install Ideal #65 wire-nuts, if necessary - detailed procedure to connect aluminum wire to (CO/ALR) switches and receptacles - procedure to connect aluminum wire to circuit breakers - if not making the changes above, what to do with existing system - wiring installed after about 1971 with the new wire is more reliable (if installed correctly) at device connections, but it has essentially the same oxide problems as the old wire; this is particularly a problem at wire-nuts; the information above is applicable to the new wire - also other very useful information.

I havn't heard of problems with service size and larger aluminum wire. The connection clamps have a large area and the procedures to use are well known to electricians.

Stove size stuff I havn't heard of problems. I would use Al listed split bolts over wire-nuts and devices must be listed for aluiminum - along with antioxide paste. The device connection clamps are a lot better than the binding screws used on switches and receptacles. Are circuit breakers listed for aluminum wire? Could split bolt a copper pigtail. And I would think strongly about applying paste and then abrading the wire as described in the paper.

Bud--

Reply to
Bud--

I don't know where you would even buy 12 or 10 ga aluminium. It is a moot point.

Reply to
gfretwell

Bear in mind this is a "home inspector" site It is not an opinion of any nationally recognized testing lab. Home inspectors live on FUD

Reply to
gfretwell

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