• ChaoticNeutralCzech@feddit.org
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    3 hours ago

    Before someone asks why so much current to earth: blue N wires are connected to it too, so it’s the PEN pole of the mostly obsolete but still very common TN-C system. Such current to PE would instantly trip GFCI/RCD in a modern TN-C-S system, now it’s just overcurrent through some appliance or wiring gone short circuit and non-compliant breaker/fuse that failed to trip.

    • Etterra@discuss.online
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      12 hours ago

      There’s a positive wire touching where it shouldn’t be. The metal object, whatever it is, leads to ground, completing a circuit. Metal acts as resistance, converting electricity to heat and light - like the filaments in a toaster or an electric heater. This can also create sparks. Either way it’s a sure way to cause a fire. If the metal is thin or melts at a low temperature, or the electricity is high voltage, the metal can melt, causing leaks. Cold liquid coming in contact with hot metal can flash to steam and possibly cause an pressure explosion or worse, depending on if there’s gas or other flammable stuff in the environment. It’s also an electrocution hazard.

      This can happen if summer critter gets in there and chews open a wire. That’s what usually causes actual electric fires.

  • Canonical_Warlock@lemmy.dbzer0.com
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    19 hours ago

    I remember one time I was at a large industrial site working on a cabinet cooler (dedicated air conditioning for large electrical cabinets) on a motor drive cabinet which was was running 480V 3 phase with feeder wires the size of my thumb when their safety guy walked by and saw me poking at the cooler fan with a screwdriver. The conversation went something like this.

    Safety guy looking rather concerned: “What are you doing?”

    Me: “Cabinet is getting warm because the cooler quit. The fan motor isn’t running so I’m trying to give it a bump start with a screwdriver to see if the motor is siezed. Gotta do it this way because otherwise I have to pull the whole cooler off the cabinet to access it properly.”

    Safety: “You know those wires there are 480V right?”

    Me: “Yup.”

    Safety: “You know those will kill you if you touch them right?”

    Me: “That’s why I’m not touching them.”