Aluminum Wiring
- Thread starter longrider
- Start date
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peter d
Senior Member
- Location
- New England
No, not in the NEC.
It is NOT recomended that you re-tourqe a connections once it's made.
It is NOT recomended that you re-tourqe a connections once it's made.
peter d
Senior Member
- Location
- New England
acrwc10 said:
Having a loose factory lug is different that what we are talking about.
Once a wire is terminated into a mechanical lug and torqued correctly, it is not supposed to be re-torqued. It serves no purpose and may damage the conductor and/or the lug.
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
I'm sure most of you are referring to larger conductors, but if we're including residential-sized branch circuit conductors, I have to disagree. I've come across some very loose device terminals with aluminum wiring.roger said:
The problem is that cycling of current exacerbates the expansion/contraction snowballing that flattens the relatively soft wires under screw heads. The resistance creates more heat and more expansion.
Once flattened, re-tightening device screws added to the increased contact area can add years of useful life to aluminum-wired houses. The connections stay cooler and the wires stay tighter.
stickboy1375
Senior Member
- Location
- Litchfield, CT
longrider said:
Nope... ... ...
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stickboy1375
Senior Member
- Location
- Litchfield, CT
LarryFine said:
Larry, do you know for a fact that those screw terminations were torqued from the beginning? I've come across loose AL connections also, but i'll bet you not one electrician from the 70's had a torque screwdriver...
- Location
- Illinois
- Occupation
- retired electrician
90.2 Scope
(A) Covered This Code covers the installation of electrical conductors, equipment, and raceways; signaling and communications conductors, equipment, and raceways; and optical fiber cables and raceways for the following: ....
(A) Covered This Code covers the installation of electrical conductors, equipment, and raceways; signaling and communications conductors, equipment, and raceways; and optical fiber cables and raceways for the following: ....
brian john
Senior Member
- Location
- Kilmarnock, Va
- Occupation
- Retired after 52 years in the trade.
brian john said:
That was an interesting article,
Reliability Considerations
So, what about the residential Al branch wiring problems of the 1960s and 1970s? Solid Al wire sizes #12 and #10 AWG were used for branch-circuit-wiring in hundreds of thousands of homes in the late 1960s and early 1970s. In the U.S., the Consumer Product Safety Commission (CPSC) reacted to reports of overheating connections by conducting an investigation. Their research concluded that Al branch-circuit wiring connections were hazardous. This has a lot to do with the misperception that Al conductors in general are not as reliable as Cu.
Unbeknown to most is that the Canadian government conducted similar investigations, which concluded that, if properly installed, Al branch-circuit-wire connections are not hazardous. Furthermore, proposals to change the NEC to eliminate aluminum-branch-circuit wiring were rejected by the electrical experts on code-making panels and by UL.
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
Of course, I don't know that. One could claim that every loose connection was never correct. I also do not own a torque screwdriver, unless you count my experienced muscles.stickboy1375 said:
I can only speak firsthand about my own troubleshooting experiences. I'm confidant that re-tightening aluminum terminations are preferable to not tightening loose ones.
stickboy1375
Senior Member
- Location
- Litchfield, CT
LarryFine said:
I can agree 100% with that statement... But I would also say that goes with copper also...:grin:
Great article brian,brian john said:
I agree with most of what is mentioned with one major exception. When it comes to using a small solid Al conductor, it has heat cycling, corrosion degradation, and vibration prone 'qualities'. I have worked a few jobs repairing Al BC's and actually witnessed what an Al back-stabbed receptacle can do to a near-by couch or curtain. The flame-thrower that comes through the receptacle sockets are due to oxidation build-up that is ignited from plugging in a high current appliance and running about 12 amps, through the device. The spring clips have minimal contact 'faying surface' area that does not provide 'an effective bond', thus produces temperature cycling that creates more oxidization and conductor pitting until there is little left of the cross-sectional area to set the time-bomb off.
There were fatality counts in the 1970's that were attributed to the aluminum installation methods then that were NEC compliant as far as workmanship interpretations went. Instead of parallel pigtailing, series wiring through the device (that are still allowed) were the main flaw. So Al wiring got a bad rap because the product driven agenda didn't really agree with the determined reasons.
The newer Al alloy conductors exceed what was available then, but the same workmanship issue and allowed product usage is still ticking. I would not allow anyone to wire residential with #12, #10 and #8 solid conductor Aluminum because of the above reasons mentioned. Yes solid #8 sucks too. I have had to repair a few of those due to the heat degradation and inadequate conductor flexibility issues that cause fires. Now if we are talking 2008 AFCI protection, then that may just become nuisance callbacks.
rbj
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