70's house aluminum wire sub panel elec Q's

[DIGITALHIPPY]

feel like bob vila with my new old house. whats up with the aluminum wire?
is it safe? what was the deal to use it? i think that sealed my deal on a subpanel, 100 amps 240/120 box, im thinking 2 AWG if i can get away with it, or whatever amps 2 awg will support, 80? should be enough for 4-8k plus the eventual mini-split. id guess i wont max 10k...with a/c.. im only going to pull 3-4k right now, ill scale up in due time. for now my electrician is replacing all the plugs, switches etc, making sure its all working ok.

anyone have any good companies for mini splits?
my work has a minisplit, it kicks ass. ill have to check the specs.
i saw that one... started with a X do it yourself install... that would be nice.

is it safe to install a window a/c into a wall between the attic and a room? that was my plan, for now. ill add low velocity exhaust to my attic. only 1100 W in a/c maybe 2K if i use all 3.....

its still cold-ish here now, so ill use my hood air for heat, but come summer ill be planning on a minisplit of some kind.

 

[PurplePotion]

Not sure where you are, but my brother just bought a house that was built in the 70s and had all aluminum. It failed inspection, and he had to get the ENTIRE house rewired with copper. Luckily, the bank that owned the house agreed to pay for it, but it was still a big hassle. Funny thing is, the other side of the neighborhood is all copper wiring .

Probably doesn't help you out much, but if you're going to do anything, use copper. I'd think if it failed inspection here, it'll just be time until it'll fail everywhere in the US, so just keep it all copper for future. There's gotta be a technical reason behind it, but I have no idea .

Good luck!

 

[Guest]

Aluminum wire as originally installed corroded at the attachment points, outlet receptacles, light fixture boxes, main panel and so on. While it was discontinued because of this failure and resultant fires, a corrective measure was used, as I recall, to go back through the affected homes, disconnect the wiring as noted above, cleaning off the corrosion, applying a corrosion inhibitor paste to the wire ends and reconnecting same.

The paste is still used when attaching the aluminum Aerial drop from the power pole at the main panel lugs. The aluminum wire, not being as conductive as copper required a greater AWG to carry an equivalent equal load as I recall.

Are there any Journeyman electricians in here that can verify or invalidate the above information? It's been decades since I had dealings with that particular issue.

Additionally there may be recourse against the previous owner(s) that sold you the home for not declaring this in the disclosure portion of the real estate sales contract that requires them to list any deficiencies.

TyStik

 

[SackausAmerika]

Aluminum wires are still used for a lot of applications. Basically when an electrical utilities co. hooks up power to your meter, the service entrance conductor is aluminum. I think the main reason aluminum isn't used for normal household wiring is because of heat build up/having to use larger conductors. A utility company running their cross country/pole to pole lines all use aluminum because it's cheaper. They don't need to worry about heat build up like in a house and use a totally different amp scale for their size wire.

You are totally correct about the paste and the amps. Aluminum has a higher resistance therefore causing more heat/more volts lost and must be up-sized....

Basic Ohm's Law states that I*E=P (I=amps E=volts P=watts). If your running everything at 120v you would theoretically have 12000w at your disposal which sounds like plenty for what you have planned(normally when rating panels you just go by amps).

Also, #2AWG Copper wire will support 115amps @75 degrees, which most lugs are rated as, so that should also be good. Just for comparison; Aluminum wire at the same size/temp is rated at 90Amps. Not a huge difference but definitely noticeable.

Just be careful doing anything yourself...Its not that complicated but hot wires look harmless until you touch them/short them out. Good Luck

SackausAmerika

 

[DIGITALHIPPY]

thanks guys for your time to reply
it was a forclosure home i picked up at auction 100k+'s below local market. so these thigns are a tossup, dumped 25k alread, what a few more? place had walpaper from the 70's i had to remove, yuch. new windows, paint throughout, plugs, switches, new bathrooms, straight gutted, carpet etc, place was done-zo.

anyway what about the main, i looked at the outside of the panel but didnt tell me much (well duh, huh?) obviousely new work will be copper,

im worried about this ;

copper from elec -> aluminum main -> copper sub.


so 2/3 is the proper cable ill assume?

if anyone knows the best type of box i should get, ive got a greybar nea my work ill go by.

 

[Guest]

DigitalHippy: You are OK, just re-read my reply to you about cleaning and applying the paste to all connections.

The copper wiring from your main to the sub panel is not an issue, just size it according to the load you intend to put on it, it is that easy. Remember that you are drawing from the main, not tapping into existing house wiring.

My home was constructed in 1964 and is solidly built. It had turquoise bath tubs, toilets, and sinks with matching tile, Butt Ugly. Not to mention bamboo wallpaper highlights, dark cabinetry, indirect fluro lighting, salmon color wood trim., brick pattern vinyl flooring and rust red carpeting along with yellow shag, aluminum single pane sliding windows, an ancient kitchen and the typical holdovers from a bygone era. That was 17 years ago-----now it is 21st century in nearly all respects.

Fixer uppers in the right location are worth the investment, if you know how to upgrade. It sounds like you have a handle on it at your end.

TyStik

 

[ThereIsHope]

Aluminum wiring is only a fire hazard or concern on circuits which are rated at 20 AMPS or less. The switches and outlets have to be rated for copper and aluminum connections and if not, FIRE.

Aluminum wiring on 30 amp breakers and above is perfectly acceptable.

Aluminum wiring needs to be upsized one guage size due to resistance properties.

FOR INSTANCE, a 15 amp breaker running copper wiring requires a MINIMUM 14 AWG wire.

If it is aluminum wiring, it would have to be 12 AWG or one size larger due to the electrical properties (greater resistance) in the wiring.

 

[twojoints]

yeah theres nothing wrong with aluminum wire if installed correctly, but for the most part it has been removed from homes because people didnt terminate their connections properly, and it was common for aluminum connections to loosen up over time- causing sparking/fires.

it is much lighter weight then copper though, and i think cheaper too..

 

[Guest]

go to: heimer.com/information/aluminum_wiring.html

There is additional info on the corrective procedures (other than replacement of wiring) to be taken, which your electrician is doing. You appear to be on course using the CU-ALR switches and outlets as replacements. Is he using the Copalum Crimp Tool on splices that may exist in your branch circuits as well?

TyStik

 

[DIGITALHIPPY]

go to: heimer.com/information/aluminum_wiring.html

There is additional info on the corrective procedures (other than replacement of wiring) to be taken, which your electrician is doing. You appear to be on course using the CU-ALR switches and outlets as replacements. Is he using the Copalum Crimp Tool on splices that may exist in your branch circuits as well?

TyStik

thanks again, your always so helpful in the building dept!

ill be starting to move in on friday, cant wait, going to get my sub-in the next day, hopefuly, i dont know what room is left.

do you think having an a/c in the wall between my attic and bedroom would overheat? its a 600W'r(6k btu) ill be using for my veg space (15x3) probably go with 3 600w's w 312 cfm 6"...
only one way to find out huh?

 

[DIGITALHIPPY]

Aluminum wiring is only a fire hazard or concern on circuits which are rated at 20 AMPS or less. The switches and outlets have to be rated for copper and aluminum connections and if not, FIRE.

Aluminum wiring on 30 amp breakers and above is perfectly acceptable.

Aluminum wiring needs to be upsized one guage size due to resistance properties.

FOR INSTANCE, a 15 amp breaker running copper wiring requires a MINIMUM 14 AWG wire.

If it is aluminum wiring, it would have to be 12 AWG or one size larger due to the electrical properties (greater resistance) in the wiring.

now im thinking of doing a sub-panel for my pc's aswell.... 700W + 500W + 640W pelter supply, plus accesories....
i feel alot of re-wireing ahead of me,

i cant even plug in my 1500W portable a/c into any on outlet i bet...

 

[Guest]

If you are saying that you want to install the AC through the wall with the compressor and coils section in the attic I would say no. You wouldn't want condensation and heat issues in there.

Glad you're glad that you are ready to move in, too...also.

It wouldn't hurt to dedicate a few new circuits in high load areas like the Laundry, Entertainment Center and your Home Office. Nearly every thing else in most homes are usually table lamps, fish tank, outlet for vibrator plug in, oops! Not. TV, and the kids PC.

TyStik

 

[DIGITALHIPPY]

hoping you guys will help me again...
panel looked maxed...









it looks like i was also wrong about some of the aluminum wireing...its only some circutis.. intresting.
anyways. ive got 1 2 and 3 and there high load im not sure how to find what there for. the double 100 is the main a/c i assume.. gas stove and laundry, so im not sure what they could be using 40 amps of 240 for??? id like to pop a new breaker in there and hit it to my panel...
any help would be great...


i just bought 2 awg thhn black, red, white and ground(10awg green) as recomended at HD conduit, a square D 6 breaker homebox subpanel a 2 pole 40amp 240 and 2 20 amp's for acc. and 2 open for future.

 

[Guest]

Check behind your gas stove and in the laundry to see if you have a 240V appliance outlet. If so test that circuit against the 40A breaker and let us know. Sometimes builders provide both gas and electrical options.

Got your PM, that was definitely good to hear. Hooah

TyStik

 

[DIGITALHIPPY]

Check behind your gas stove and in the laundry to see if you have a 240V appliance outlet. If so test that circuit against the 40A breaker and let us know. Sometimes builders provide both gas and electrical options.

Got your PM, that was definitely good to hear. Hooah

TyStik

You must spread some Reputation around before giving it to Ty-Stik again.

thanks...

ill have to check the stove...

my next step im assuming is to turn off the breaker and then figure out what dosent work.... LOL