Is there a simple way to know what type of wire to use (stranded v. solid) and what gauge? Previously, I just matched what was already in place, but now we are in a 1932 house and standards have probably changed.
Janet
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I always use what I can find surplus or at the best price.
It is kinda difficult though to pull 10 AWG solid around 5 90 deg bends in conduit <G>
Gauge depends on if you need to conform to code or not or where it is used. Just speced some 20 AWG runs in an airplane for 15A.
Have even buried old extension cords to power sheds.........
However, the NEC experts will be along shortly.....<G>
>>>Is there a simple way to know what type of wire to use (stranded v. solid) and what gauge?
There are rules, both in the NEC and in books that simplify and explain the NEC.
The factors are basically the amount of current (this determines the size) and the application of the wire (branch circuits using non-metallic sheathing, stranded wire in conduit, armored cable like TECK, well pump wire, etc.)
The rules aren't complex, but I don't know if you'd call them "simple" as you say. It boils down to whether you want to do it "right" or if you want to be "resourceful" (I use the term somewhat loosely) like junkhound. ;)
Scott.
Roughly, for solid NM-B in a house, based on the circuit breaker or fuse protecting the circuit, what gets put in is -
15 amps 14 gauge
20 amps 12 gauge
30 amps 10 gauge
40 amps 8 gauge
But there's a hell of a lot of qualifications and rules
Forrest - not an electrician; will get flamed for this
Generally, stranded wire is used either in conduit of some form, or perhaps inside of fixtures. Solid is generally employed as romex or some derivation thereof, although I will bet there is a lot of BX in your house (spiral steel jacket over 2 or more solid conductors).
There are lots of rules, many here will be happy to advise with some specifics in a question.
For example, say you need #14 wire in a cable configuration of 2 conductors plus a ground wire.
NM-B (Romex) is available in solid wire in this configuration.
SJOW is also available in stranded wire in this configuration.
What's the difference? They both have the needed size of conductor; both have the needed number of conductors; both have an outer jacket.
Are they legally interchangable? NO.
Jim
"NM-B (Romex) is available in solid wire in this configuration.SJOW is also available in stranded wire in this configuration.What's the difference? They both have the needed size of conductor; both have the needed number of conductors; both have an outer jacket."But they have completely different types of insulation on the wire and the jacket.People don't realize that the insulation determines the max allow wire temperature thus the current ratings.And the sheathing also is rated for the type of application. Perminately installed, flexible, sunlight resistance, oil resistant, etc.And I believe that the larger size NM is available stranded. I know that SE cable is usually stranded..
William the Geezer, the sequel to Billy the Kid - Shoe
That was exactly the point of my #14 awg cable example to Janet - seemingly "the same wire" but they are not legally interchangable for many applications.
>>...larger size NM is available stranded.<<
In my locale, copper NM commonly is made up with solid wire up to #10; #8 and larger is stranded. The strands are not very fine, but they are strands. Not very flexible either, more flex than solid......
Have also used some pretty flexible, sheathed, stranded, two conductor, cable specifically used on boats - don't even know whether it was rated for 120v as it was not an issue -- we used it for 12, 24 and 32v DC systems.
Jim
Never underestimate the value of a sharp pencil or good light.
Edited 11/5/2009 11:37 am ET by JTC1
Wire types can be as simple as you want them to be.
The easy part is wire size; copper is copper, and it matters not (from a current carrrying aspect) whether it's a single fat wire or a twist of many finer strands.
The insulation is what makes the difference. Apart from keeping the electricity in the wire, the insulation has to stand up to the expected uses.
The easiest way is to use a wire 'named' for its' use. For example, use pump cable for submersible pumps, lamp cord for lamps, etc.
When you use a listed wire for its' intended use, you can be sure that the wire has been tested under realistic situations, and you can expect it to perform well.
A classic example of this is what happens when someone buries 'premium' extension cord material. Unlike the superficially similar 'underground' cable, the extension cord will quickly degrade in most soils. I've pulled up cords that were under just an inch or so of dirt and plant debris, and all that remained was the copper; any surviving insulation was brittle, cracked, and crumbling.
Alas, these are differences often glossed over by the help at the box stores; these folks have no idea what the wire designations mean. Ask for a sixe of 'extension cord' that they don't carry, they're likely to try to sell you Romex or service-entrance wire instead.
copper is copper
99.9% Cu yes, more impurities no.
For a history on how 'we' found that out, google the first transatlantic cable - which used copper twice the resistance of the electrolytic copper we use for conductors today.
"and it matters not (from a current carrrying aspect) whether it's a single fat wire or a twist of many finer strands."Not so true for things other than 60HzJust say'in.....
OK, you caught me ..... but let's not muddy the waters here. If the guy doesn't know the difference between SO and THHN, I certainly hope he's not working some place that has 4106 v at 400 hz!
twisted wire does NOT help impedance if it is uninsulated, you are thinking litz wire, where every strand is insulated (aka magnet wire strands)
Somewhere in the addled recesses of my cortex I seem to recall something about all the current (field...heck, whatever that 'lectricity stuff is) running on the surface of the wire.....but I 'member lots of things that ain't so......
Somewhere in the addled recesses of my cortex I seem to recall something about all the current (field...heck, whatever that 'lectricity stuff is) running on the surface of the wire.....
Yes, called the "skin effect" - but it's primarily a factor at higher frequencies.
http://en.wikipedia.org/wiki/Skin_effect
>>>in the addled recesses of my cortex I seem to recall something about all the current (field...heck, whatever that 'lectricity stuff is) running on the surface of the wireWhooooeee... Somehow I think this thread has headed in the exact opposite direction that the OP was wanting. IIRC she was asking for "simple".Let's start a different thread for fluxes, fields, matrices, etc...Scott.
when someone buries 'premium' extension cord material
I saw that <G>
FWIW, I have NEVER buried anything 'premium', the only cord I bury is old stiff cracked PVC cord (usually free at garage sales or on the curb Monday AM with the garbage) -- with roofing tar over the cracks <G>
Would not want the OP to think anyone at BT would be dumb enough to bury 'premium' extention cords <GGG>
Seriously, I agree with you on the implication that someone who asks the original question needs a lot of reading to even understand the answers, even if not 'tongue in cheek'
My apologies to OP, but since your profile says 'old bat', you could fly down to the local library and read some of the basic self-help wiring books to get started. Taunton sells some books that some folk here shill for occasionally - see Mods, even left an opening for 'Rex fans'
I will be assembling a ceramic infrared heater, using high-temperature electrical wire inside the housing. But what size wire should I use?--it comes in gauges 4 through 22.
The infrared emitter is 1000 watt, 120 volt, and each lead wire is 14 strands of 29-gage wire.
I need less than two feet of wire, so cost is not an issue. Is there any reason I shouldn't buy the heaviest gauge?
Janet
inside the unit only or up to the unit and or up to the unit and then on into the unit...
HYPO105C internally..
12GA to the unit... more info to determine just what type of feeder to the unit..
is this unit freestanding, surface mounted or built in???
does the unit have a built in J box or line tap???
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WOW!!! What a Ride!
Forget the primal scream, just ROAR!!!
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[blank look] Uh... I don't know how to answer your question.
Let me describe the project. It's a hand-held infrared paint remover, using a ceramic emitter instead of quartz tubes. It looks like this Full Trough Emitter
(except it will say "120V FTE 1000W").
It goes into aluminum housing with insulation between the reflector and housing. This same space is where I connect electrical wire to the leads of the emitter.
I don't know what gauge of high-temperature electrical wire is the absolute best choice, and if high-temp connectors are required. I hope not, as the terminal connectors and ceramic wire nuts are sold in bulk, while I only need 2!
Janet
IMERC,
What is HYPO105C? Didn't get any hits on Google.Is a "feeder" a bridge between the power cord and the leads of the emitter?Janet
He is talking about a wire with insulation rated 105c. If you read most wire THHN-THWN spools you will see they are also MTW rated at 105c for wiring appliances.
http://gfretwell.com/electrical/Wire%20spool%20label.jpg
Thanks, I didn't know that. I think I will repost this under a new subject. The wire question is the only thing stopping me from placing the order.Janet
You cant go wrong with #12, I'd use solid.
Dam_inspector,Thank you, I will use 12-gauge. They don't offer solid, but renosteinke said that stranded doesn't make a different in most cases. Are high-temperature connectors necessary?Janet
Edited 11/22/2009 1:45 pm by jyang949
I would try to use them, but what kind of a connection is it? Wire nut? spade terminal? screw?Appliance parts stores will sell individual high temperature connectors, they are used in ranges and ovens etc.I'll ask my dad if he has any, looks like you need the small #7 ones. He used to work on appliances.
Edited 11/22/2009 2:19 pm ET by Dam_inspector
I guess the connection will be anything I decide it to be. The housing provides a screw for grounding, but nothing else for attaching wires. Appliance parts stores--that's a good idea. Thanks!Janet
I found #7 ceramic wire nuts at Sears! That was after they told me they didn't carry them. :)Janet
Everybody knows the "premium" ones are to be left out to be stolen, cut in two or more pieces by accident, or have someone remove the ground pin.
Bob