#linuxcnc Logs

Mar 04 2021

#linuxcnc Calendar

07:38 PM XXCoder: woodpeckers?
07:44 PM roycroft: since i did not have to work on my bandsaw after work today i was able to cut the grass in the front, and start opening up some of the herb garden beds
07:44 PM roycroft: i was actually able to clean up the mojito mint planter before the new growth got in the way
07:44 PM roycroft: woodpeckers are a manufacturer of woodworking tools, mostly metrology tools
07:44 PM roycroft: they operate on a limited run, preorder basis for most of their stuff
08:00 PM roycroft: roycroft.us/Bandsaw
08:00 PM roycroft: there, for them that were asking
09:08 PM enleth: veek: if that aluminum cable is on your property, make plans to replace it with copper
09:09 PM enleth: veek: small gauge aluminum wiring is a persistent fire hazard
09:09 PM enleth: things happen to this crap that no one foresaw when it was installed
09:11 PM enleth: solid aluminum wires are still widely used for underground power cables due to cost, but those are expected to only be installed and terminated by trained presonnel supplied with proper connectors
09:11 PM enleth: and even with that assumption, many places require strict inspection of those connectors after crimping and before it's covered and energized
09:17 PM veek: enleth, thanks
09:18 PM enleth: some go as far as to require only transparent heatshrink tubing to be used on the connectors to make them inspectable even after installation
09:18 PM enleth: and I've seen this mandated by private, internal electrical codes in telecom companies, even if the local national code doesn't require it
09:19 PM enleth: they wouldn't do it without a very good reason
09:20 PM veek: enleth, i have junked solid 15A aluminium wire.. as in.. it was removed and I need it to power some Power Tools - angle grinder, chainsaw etc
09:20 PM veek: outdoor use..s/need it/repurpose it
09:21 PM enleth: so it's going to be used as an extension cord, not permanently fastened to anything?
09:21 PM veek: nope..
09:21 PM veek: basically a straight line from socket to point of use
09:22 PM veek: it's pretty unwieldy
09:22 PM roycroft: i was going to disagree with enleth on this subject, but find myself agreeing more than disagreeing now that he's clarified his position
09:22 PM roycroft: i was going to suggest that it could be difficult and expensive to replace aluminium wiring, and that it can be made quite safe
09:22 PM roycroft: and i still believe that
09:23 PM roycroft: i would never install it new these days
09:23 PM roycroft: and it certainly has to be terminated properly to be safe
09:23 PM veek: roycroft, terminated? ground wire you mean?
09:23 PM roycroft: i mean connected to whatever it connects to
09:24 PM roycroft: be it another wire, a receptacle, switch, whatever
09:24 PM roycroft: i would not repuposed junked aluminium wire
09:24 PM roycroft: repurpose, rather
09:25 PM enleth: veek: it'll start cracking if it's moved around at all
09:25 PM enleth: use it while it lasts if you need to, but expect it to fail
09:27 PM roycroft: clean the wire ends properly, use a proper antioxident, only use components rated for aluminium wire, use a torque screwdriver/wrench when making the connections, and know the proper torque specification for them
09:27 PM roycroft: don't guess
09:27 PM W1N9Zr0: and if your insurance finds out you are reusing junk aluminum wire, they're not going to pay out when your place burns down
09:28 PM veek: roycroft, any video on all this.. I just use normal screwdrivers and such
09:28 PM roycroft: if it's installed properlly and inspectedd an insurance company cannot deny a claim
09:28 PM roycroft: i don't know of any videos offhand
09:29 PM Tom_L: just don't use the stuff
09:30 PM Tom_L: heat cycles loosen the wires then they arc
09:30 PM roycroft: there are three concerns that you have to keep in mind:
09:30 PM roycroft: 1. aluminium oxidises almost instantly, and the oxide layer causes a poor connection that is prone to arcing
09:31 PM roycroft: 2. thermal expension of aluminium is much greater than of copper, making it challenging to make secure connections
09:31 PM roycroft: 3. aluminium tends to get brittle and crack over time if not properly protected
09:32 PM roycroft: all of these concerns greatly increase the chance of fire if the installation is less than perfect
09:32 PM roycroft: there are other issues, but those are the main ones that come to mind offhand
09:33 PM enleth: there actually are screw terminals for aluminum that don't require a torque screwdriver, they have screw heads that shear off when the target torque is exceeded - but they're even more expensive than the regular aluminum-rated ones and you're even less likely to find them at any DIY store
09:33 PM roycroft: ok
09:34 PM roycroft: the point is that it is much more important to torque the screws properly when terminating aluminium wires than with copper wires
09:34 PM roycroft: however that is done
09:35 PM roycroft: and it's important to do it properly with copper wires
09:43 PM Tom_L: :)
09:43 PM skunkworks: Thanks tom!
09:52 PM veek: ah there's a whole wiki on aluminium conductors https://en.wikipedia.org/wiki/Aluminum_building_wiring
09:53 PM roycroft: it's not inherently dangerous
09:53 PM roycroft: it just needs to be done correctly, every time
10:59 PM skunkworks: you tighten the connectors. Then tighten them again. Then a week later tighten them.
10:59 PM skunkworks: then again