| How did that work, do you suppose? How does one connect a lamp to 3-phase power? Are/were there 3-phase fluorescent tubes available? Or are we relying on the spinny-thing that is to be observed to somehow be illuminated by all three phases, with three lamps or fixtures, simultaneously? Without such malarcky as shadows or inverse-square to muddy our vision? Or maybe a multiplicity of single fixtures with 3 tubes -- one tube per each phase? And even then: Doesn't it still strobe somewhat at (50*3*2)=300 or (60*3*2)=360Hz, instead of the 100- or 120-Hz that a shop lit by a single phase might provide? (LEDs are out-of-scope of this question, of course: Line-voltage LED lamps can have integrated electronics and can therefore have diode elements that are driven by things that approach [or even achieve] DC, which changes the rules. And, of course: Incandescent lamps have enough persistence that stroboscopic effects are generally not an issue with a human eye.) |
You typically connect 1/3 of lamps on one phase, one third on another and so on.
In the UK we use a 230V single phase system for most things (industrial/commercial often use 400V) (if all three phases are in use it's 400V - you may see it as 415V but we harmonised with Europe to 400V) so lighting expects that 230V anyway, you still have a common ground, you just run the live for each phase to the lamp/light.
Power delivery to homes is in effect a single phase out of a three phase supply with each house (often but not always) wired in sequence, so house 1 is Phase 1, house 2 is Phase 2, house 3 is Phase 3, house 4 is phase 1 and repeat.
We have standard colors for this as well (as do most jurisdictions), neutral is always blue but the phases are Brown, Black and Grey
When I trained as an industrial electrician they where different colors, they changed in 2006 so that just makes me feel old (used to be Red, Yellow, Blue with Black for Neutral).