Electronics > Projects, Designs, and Technical Stuff

Of mains distribution and aluminum wire

<< < (3/3)

rstofer:

--- Quote from: tkamiya on March 11, 2019, 05:46:47 pm ---Aluminum wires problem was caused by several factors:

1)  Aluminum wires are rated LOWER than copper wires but electricians did not always treat it as such
2)  Aluminum wires have high resistance and thus prone to heat up when not correctly sized
3)  When aluminum wires and cu can be joined but without proper antioxidizing paste, electrolysis will promote corrosion

All that caused house fires.

--- End quote ---

I don't think any of those items were an issue in industrial environments.  What I think was the real problem with residential is the backwire push-in connections on receptacles or the non-clamping style screw connector - in other words, the cheap spec grade wiring devices.  The internal piece on the backwire device has a sharp edge to cut in to the copper wire and would eventually cut through the aluminum wire.  I never used aluminum for residential and, even in industrial, only for long runs of high current circuits where there was a demonstrable savings over copper wire.  The savings had to be huge because a) the wire had to be bigger, b) the conduit had to be bigger and c) we had to use crimp-on aluminum to copper fittings before terminating on a circuit breaker.  I would think about it for 400A circuits but probably nothing below that.  Maybe 225A but that's a stretch.

These days we have to use arc detecting circuit breakers on certain residential circuits.  I imagine this is an offshoot of aluminum wire.  I can't imagine anyone using aluminum wire for residential branch circuits but it might happen for larger panel feeders.

Aluminum continues to be the leading conductor for utilities and has been for more than 100 years.

https://en.wikipedia.org/wiki/Aluminum_building_wiring


Kalin:
Here in Canada the cost savings are significant. Aluminum being 1/3 the price for 200A capable cable. So that tends to be my go to for that size upwards. Another thing that comes into play is the different rates of thermal expansion between copper and aluminum allowing space for a high resistance fault between wires twist together. I have never seen that myself but I know guys that have seen it and it can be dangerous.

Sent from my SM-G965W using Tapatalk

soldar:
This page explains it: https://www.carsondunlop.com/training/resources/the-true-story-behind-aluminum-wiring-part-one/

Also https://en.wikipedia.org/wiki/Aluminum_building_wiring

tkamiya:
I haven't heard of the problem in industrial or business setting either.  But in Florida and in many other parts of country, business are done differently from residential setups, for example, mandatory use of conduit.  Most electricians don't do buss bars either and they are usually aluminum.

I have seen so many improperly done copper to copper connections, too, and they were supposedly done by "professionals".  In that environment, if one introduces something slightly more complicated, it can go very very badly. 

Navigation

[0] Message Index

[*] Previous page

There was an error while thanking
Thanking...
Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod