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Cake day: March 31st, 2025

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  • you don’t have to have three phase circuit to be affected by floating neutral in three-phase substation upstream. in some places in us there are 208v interphase three-phase circuits, which give 120v phase to neutral, which is distributed as a pair of wires as single-phase circuit. this is also normal way to deliver single-phase power in europe, as it’s most efficient use of conductor. (from 400v three-phase circuits) in case more power is needed than single-phase circuit can deliver, three-phase circuit is installed

    if there’s switch on device, it’s 2p1t meaning both phase and neutral are switched. if it’s permanent, non-pluggable circuit, like lightning, it’s okay if only phase is switched (neutral is connected permanently)


  • it’s a bad practice to design appliance in such a way to assume that neutral will have low voltage, because in case of neutral failure in three-phase circuit you can get full voltage there, and there can be a couple of volts difference (sometimes more) between neutral and ground even in normal circumstances

    it’s better to cut off both live and neutral at the same time anyway, especially if there’s no standard which is which. also, as device designer you don’t know if it’ll be used on a circuit that has neutral and phase where you think it’ll go or not. (ie british appliance used on unpolarized circuit, like type F. adapters exist)









  • Type E and F plugs are not really a thing anymore, today it’s more common to find combined Type E/F plugs.

    Fuses in british plugs are a mistake and only a requirement because of sketchy practices allowed in british electrical code immediately after WW2. Nobody else does that because nowhere else electric code is built in such a way that it is necessary. Switch seems to be mildly useful tho






  • with wood, the problem was with lignin which is tightly crosslinked, meaning that it’s insoluble and organism willing to eat it has to secrete some enzymes to break it down in smaller bits that can be absorbed

    depending on plastic, this first step might be easier or even happening on its own. there are already bacteria that feed on nylon but nylon starting materials are easier to digest for them