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What’s wrong with metal tubing indoors? Outside is another matter. Those galvanized steel tubes don’t last very long underground, and the results are terrifyi
by amluto 3y ago
What’s wrong with metal tubing indoors?
Outside is another matter. Those galvanized steel tubes don’t last very long underground, and the results are terrifying. And nothing in the code requires ground fault protection upstream of a 120V circuit running through a corroded steel tube underground.
- marcosdumay 3y agoThey conduct electricity. Thus if you have a leak from one conductor somewhere in your house (that without ground fault protection goes undetected almost every case) and gets a different one from a different wire, you now have a constant-on heater passing through God knows where, ready to start fires. A single leak also gives you a minor risk of electrocution. But the fire hazard is the important one.
- amluto 3y agoThis is possible with nonmetallic conduit, too, as well as with NM-B. At least metallic conduit has a decent chance of containing the resulting mess inside the conduit. The right solution is ground and arc fault protection, both of which are available, and one of which is increasingly required in the US.
- marcosdumay 3y agoYou seem to be thinking about short circuits. That's not what my post is about. (Anyway, plastic conduits are quite capable of containing the mess.) And yes, they are way less dangerous if you have ground fault protection. To the point that I'm not sure it's still important to ban them. But they don't have any upside either.
- amluto 3y agoI think metal conduits are most useful in more industrial-ish spaces where they're exposed -- they're quite resistant to getting banged up. Schedule 80 PVC works, too, but it's harder to work with than steel (at least for an electrician with the right tools).
- marcosdumay 3y agoIndeed, they are useful for exposed installations.