| General > General Technical Chat |
| The real reason why North America uses 120v instead of 240v. |
| << < (12/17) > >> |
| mcovington:
--- Quote from: NiHaoMike on November 25, 2022, 01:25:18 pm ---Why not have 120V be 2x 60V to ground? Wouldn't that be the safest way to have 120V? --- End quote --- I like that idea -- with GFCIs (residual current devices) on both sides. Hmmm... Currently existing American appliances would all work, I think. |
| mcovington:
--- Quote from: themadhippy on November 25, 2022, 01:31:47 pm --- --- Quote ---Why not have 120V be 2x 60V to ground? Wouldn't that be the safest way to have 120V? --- End quote --- We do in the uk.ok its 55-0-55v ,it mainly used on construction sites. --- End quote --- Interesting. With American-type 120V tools? |
| AVGresponding:
--- Quote from: Monkeh on November 25, 2022, 03:41:56 pm --- --- Quote from: AVGresponding on November 25, 2022, 03:38:23 pm ---Larger homes often have 3-ph supplies in the UK. --- End quote --- I wouldn't say often, and many DNOs actively refuse to supply such. And still not 480VAC. Mind you, there's the far rarer option of a split-phase supply.. --- End quote --- I would, and I've worked in a few. When you get to the size of 10+ bedrooms and multiple wings and/or sub-buildings, it's common, and necessary. And 3-ph in the UK is most commonly 400VAC (nominally, actually more like 415, blame weird EU harmonisation attempts, just like the "230" in the UK is more likely to be between 240 and 250), not 480. Some specialised use cases exist of course, ie railway signalling at 650VAC 1-ph etc. |
| TimFox:
--- Quote from: mcovington on November 25, 2022, 03:51:06 pm --- --- Quote from: themadhippy on November 25, 2022, 01:31:47 pm --- --- Quote ---Why not have 120V be 2x 60V to ground? Wouldn't that be the safest way to have 120V? --- End quote --- We do in the uk.ok its 55-0-55v ,it mainly used on construction sites. --- End quote --- Interesting. With American-type 120V tools? --- End quote --- I encountered the 110 VCT transformers during an installation in UK: it seems to be mandated when a long extension cord is required from the wall to a power tool. The connectors used are quite different from normal UK or US plugs. The local workers did not use these extra transformers very often, using cordless power tools (battery operated) when possible to meet the safety regulations. |
| themadhippy:
--- Quote ---it seems to be mandated when a long extension cord is required from the wall to a power tool. --- End quote --- nope,its just to reduce the risk of a fatal shock on damp building sites --- Quote ---The connectors used are quite different from normal UK or US plugs. --- End quote --- compared to domestic stuff yes,but fairly common else were and come in a wide variety of voltage and current ratings |
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