Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Electrical

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Search this Thread Display Modes
Old 07-28-2008, 11:14 AM   #1
walt1122
 
Join Date: Aug 2007
Posts: 201
Share |
Default

Aluminum wire size/ guage / amps?


Hi all two questions. Have a roll of aluminum wire but can't read the size. I'm getting about .240 inch per leg. Having trouble finding a chart that tells me size in aluminum, copper yes, aluminum no. Know where I can find one or got any idea what size this might be? Also there are some abrasions on the outer skin and a couple breaks/tears to. Nothing into the sheathing of the wire but is this a problem, can it be fixed so the I can use it and not have a problem with inspectors. About 150 feet of wire and I need some of it for my HVAC ( new construction) for the heating element. Probably needs to handle 5k or might use 8k if it turns out to big big enough to carry enough amps.

thanks for any help or suggestions

Walt

walt1122 is offline   Reply With Quote
Old 07-28-2008, 11:21 AM   #2
Res Ipsa Loquitur
 
Join Date: Dec 2007
Location: Southeastern PA
Posts: 363
Default

Aluminum wire size/ guage / amps?


Gauge would be the same for both copper and aluminum- the difference is the amount of amperage it can carry. For service entrance conductors aluminum is usually 2 gauges larger than the same in copper.

__________________
Did you ever stop to think, then forget to start again?
handyman78 is offline   Reply With Quote
Old 07-28-2008, 11:54 AM   #3
walt1122
 
Join Date: Aug 2007
Posts: 201
Default

Aluminum wire size/ guage / amps?


Hi handyman78, thanks but I think I'm looking for something a little more definitive. I understand that the guage would be the same but it is what the carrying capacity of the aluminum wire would be based on the size of the wire AND if there is an issue with the tears in the exterior grey plastic sheathing even though there aren't any breaks in the individual wire coatings. I'm trying to do alot of this work myself prep the HVAC and electric service for the contractor so I can maybe keep the prices down. If I can supply the wire that should be a savings. I have had this wire around for years but I would like to use it instead of scrapping. But only if it doesn't cause issues with the inspector.

thanks again

Walt
walt1122 is offline   Reply With Quote
Old 07-28-2008, 01:02 PM   #4
Member
 
Join Date: Jul 2008
Location: NW of D.C.
Posts: 5,990
Default

Aluminum wire size/ guage / amps?


Quote:
Originally Posted by walt1122 View Post
I'm getting about .240 inch per leg.
Also there are some abrasions on the outer skin and a couple breaks/tears
Probably needs to handle 5k
240 mils = 240^2 = ~57,600 Circular Mils.
My wire table shows 52,620 CM for #3 and 66,360 CM for #3.
Another wire table for [probably] solid wire shows 66370.0 CM for #2.

Isn't the cable marked? If a manu part number is on the cable, Googling it might come up with the specs on this cable.

By the way, #2 is twice the CM of #5 is twice the CM of #8, and so on.

Moisture is the enemy of cables once it's inside. Openings will allow water to wick in [by Capillary Action], even against gravity, and eventually destroy the cable.

5k watts? At 240v?

Last edited by Yoyizit; 07-28-2008 at 01:22 PM.
Yoyizit is offline   Reply With Quote
Old 07-28-2008, 01:29 PM   #5
walt1122
 
Join Date: Aug 2007
Posts: 201
Default

Aluminum wire size/ guage / amps?


Hi Yoyizit, please clarify
"My wire table shows 52,620 CM for #3 and 66,360 CM for #3."??
Which number is wrong! and can you tell me how many amps can each of these wires carry?

Yes, haven't done the complete calculations yet but I'm thinking I need at least 5k watts at 240V and might need as much as 8k @ 240V. to give me the BTUs/H I will need. Just trying to find a use for the wire. I have some kind of mold/dirt along the entire length of the wire. I have tried everything to clean it and the only way is to scrub it with 3M scotch pads and I'm either removing the AWG wire size info or it has come off on its own. If it is the right size it will be used indoors.

thanks

Walt
walt1122 is offline   Reply With Quote
Old 07-28-2008, 02:01 PM   #6
Member
 
Join Date: Jul 2008
Location: NW of D.C.
Posts: 5,990
Default

Aluminum wire size/ guage / amps?


Quote:
Originally Posted by walt1122 View Post
Hi Yoyizit, please clarify
"My wire table shows 52,620 CM for #3 and 66,360 CM for #3."??
Which number is wrong! and can you tell me how many amps can each of these wires carry?

Yes, haven't done the complete calculations yet but I'm thinking I need at least 5k watts at 240V and might need as much as 8k @ 240V. to give me the BTUs/H I will need. Just trying to find a use for the wire. I have some kind of mold/dirt along the entire length of the wire. I have tried everything to clean it and the only way is to scrub it with 3M scotch pads and I'm either removing the AWG wire size info or it has come off on its own. If it is the right size it will be used indoors.

thanks

Walt
That's the problem; I don't know which number is wrong/right, and they can't both be right if they are one whole gauge number off.

The amps a wire carries depends on ambient temp and what insulation it uses. Power lines across the country get up to 100C.

Yeah, use the wire inside.

Electricians do this calc every day of their lives; I hope one of them answers.

I can probably step through this procedure using my 1999 NEC interpretative book by Mr. Mullin. Otherwise the volts, amps, wire temp and voltage drop all chase each other around forever. And, it's not just Ohm's law; you need to follow safety rules.

But, if you come up with the length of wire that you're using, the wire insulation type, the current draw (max and steady state) of the load I can tell you how it will perform, based on Ohm's law and accounting for conductor temp.

Don't put any more labor into this cable.
You can also use it for jumper cables, but you need those humongous alligator clips.
Yoyizit is offline   Reply With Quote
Old 07-28-2008, 02:07 PM   #7
UAW SKILLED TRADES
 
Stubbie's Avatar
 
Join Date: Jan 2007
Location: Kansas
Posts: 4,978
Default

Aluminum wire size/ guage / amps?


My advice for what it's worth. I would never use 'used' (obviously questionable) wire INSIDE my home or for new construction.

You are prone to many errors trying to figure out what wire you have without identification on the outer sheath. You could have wire/cable not approved to enter inside a building.

You also don't mention what you are measuring just the bare wire or bare wire and insulation or what?

Don't use it and you can sleep at night.....
Stubbie is online now   Reply With Quote
Old 07-28-2008, 02:28 PM   #8
electrical contractor
 
Join Date: Feb 2008
Location: Georgia USA
Posts: 181
Default

Aluminum wire size/ guage / amps?


I agree 100% with Stubbie, it would be hard for me to sleep in a house with wiring I was not sure about. Sell it for scrap and get a piece of copper wire for your heat/ac. Post back with the amperage requirements of both air handler and compressor and we can tell you what size wire you need.
__________________
Jimmy

Life is tough, Life is tougher when you are stupid.
wire_twister is offline   Reply With Quote
Old 07-28-2008, 02:39 PM   #9
walt1122
 
Join Date: Aug 2007
Posts: 201
Default

Aluminum wire size/ guage / amps?


thanks guys, bare wire only no insulation. Just looks bad have XHHW #6 just like it I took down ar the same time when we shut down facility and moved business South. Just can't remember what piece of equipment it powered. The #6 is maybe 50% smaller. Just trying to make use of the wires the larger is dirty and having trouble cleaning. I just thought I could find an easy way to determine if it is viable before I waste too much time cleaning it if the cuts will be a problem with the inspection and or if it isn't large enough to carry the amps I need.

Walt
walt1122 is offline   Reply With Quote
Old 07-28-2008, 03:03 PM   #10
UAW SKILLED TRADES
 
Stubbie's Avatar
 
Join Date: Jan 2007
Location: Kansas
Posts: 4,978
Default

Aluminum wire size/ guage / amps?


My guess is your inspector might turn it down.... and will turn it down if he looks past the terminations for the insulation identification due to its appearance.

Take it to recycle and spend the money on new wire.

If your hell bent on using this stuff here is a size chart my guess is #2 or #3 al. #2 al is 75 amps and #3 al is 65 amps. These are the ampacities for insulated wires with 60C insulation.

http://www.litz-wire.com/wirediminsions.html

But inspectors don't catch everything so I'd be real freakin sure what you have there or you may be sleeping under the stars.

stubbie
Stubbie is online now   Reply With Quote
Old 07-28-2008, 03:41 PM   #11
walt1122
 
Join Date: Aug 2007
Posts: 201
Default

Aluminum wire size/ guage / amps?


thanks Stubbie for the chart and thanks to everyone for their input. Based on the issues I probably will have to forget this and just rethink the whole thing. Wire_twister I'm still trying to get a reliable heat load calculation so I can figure out what size system I need. The contractor I had said I needed a high end 2 stage 2 ton heat pump but when I asked him for his Manual J calculations he said he didn't need to do them cause he KNOWS what I need. Well I had him do the calculations and the system is way, way to big for the 3 car garage w/apartment above we are building. Plus he put in a crappy duct system so I fired him. Soon as I know what size system I really need I will come back and ask you all to help size the wire and breakers.

When I did this house I had to put in two disconnects at the airhandler. Think they were a 60A? and a 90A for a 6 ton geothermal heat pump with 15k? electric backup. Is this the normal way to handle? Ran copper wire through conduit so I might do the same thing in Tenessee cause they already put up the sheetrock in the garage before I had a opportunity to get down there from our home in New Jersey. Probably easier that breaking through walls. what would you guys suggest??

thanks

Walt
walt1122 is offline   Reply With Quote
Old 07-28-2008, 04:21 PM   #12
UAW SKILLED TRADES
 
Stubbie's Avatar
 
Join Date: Jan 2007
Location: Kansas
Posts: 4,978
Default

Aluminum wire size/ guage / amps?


Wise decision making Walt. It is normal to have disconnects at airhandlers and heat pumps. Often times backup heat if electric has supplemental overcurrrent protection (breakers) on the equipment. Then you have an ocpd's in the main panel or sub-panel. So it is hard to advise without knowing what the equipment is, we can give wire sizes and ampacities given the nameplate information but it is really adviseable to have the manufacturers instructions in your hand so you can view the wiring schematic and design.
Stubbie is online now   Reply With Quote
Old 07-28-2008, 07:52 PM   #13
Member
 
Join Date: Jul 2008
Location: NW of D.C.
Posts: 5,990
Default

Aluminum wire size/ guage / amps?


Quote:
Originally Posted by walt1122 View Post
The contractor I had said I needed a high end 2 stage 2 ton heat pump but when I asked him for his Manual J calculations he said he didn't need to do them cause he KNOWS what I need. Well I had him do the calculations and the system is way, way to big for the 3 car garage w/apartment above we are building. Plus he put in a crappy duct system so I fired him.
If you're going to spend kilobucks I'd get at least 3 estimates.
Yoyizit is offline   Reply With Quote
Old 07-28-2008, 10:10 PM   #14
walt1122
 
Join Date: Aug 2007
Posts: 201
Default

Aluminum wire size/ guage / amps?


that's exactly what I told my builder as he gave the work to his buddy. I said get me some more quotes cause his price sounds high. And i was right. He wanted over 8 grand for this system. Couple of 14 inch round main ducts down the length of my garage ceiling dropping what was a nice 10 foot ceiling down to 8 feet when they get boxed in. Pissed me off cause he wasn't even supposed to be doing the work. But because my builder gave him the go ahead I felt responsible and paid him for what he did. Cost me 2,500 bucks for something I can't wait to tear down and replace with some rectangular 8 x 24 or so that he should have put up in the first place. At least I didn't get caught for the other 5,500 for the heat pump Can't wait to get rid of this builder been nothing but bad since I hired him. Got great recommendations but I don't know how!

take care

Walt
walt1122 is offline   Reply With Quote
Old 07-28-2008, 11:15 PM   #15
Member
 
Join Date: May 2008
Location: Apple Valley, MN, USA
Posts: 999
Send a message via AIM to theatretch85
Default

Aluminum wire size/ guage / amps?


I understand you probably won't use this wire anyway, but .240 inch sounds like #6 wire, and in aluminum it would only be good for about 40 amps. I have a bundle of #6 4 conductor aluminum here, probably pretty close to the same stuff you have (it has a gray outer sheath).

theatretch85 is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Generator as sole power source NGuy Electrical 29 12-20-2008 12:29 AM
14 guage for 20 amps bdog1234 Electrical 6 02-24-2008 01:34 PM
Wire size and Breaker size for remodel ?? Skydmark1 Electrical 12 12-15-2007 05:00 PM
Aluminum wire? Which outlet to use? papashaq Electrical 6 08-27-2007 05:36 PM
wire size wire to 10kw furnace? lochcarron Electrical 1 04-10-2005 07:43 PM




Top of Page | View New Posts

Copyright © 2003-2014 Escalate Media. All Rights Reserved.