you can run some motors on 480 or 240 by changing the configuration in the peckerhead to form a delta or wye/star connection. How does that work? Seems like voltage goes through the same coils would need the same voltage. It’s not like there is a nuetral in the middle of the star
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Motors can have additional coils, wired in series or parallel. Wiring delta or wye(star) configuration determines if it’s series(higher V) or parallel (lower V).
The motor coils are the load on the circuit. Voltage drops across them to do work. So we can simplify them by treating them like resistive components. If you wire a lightbulb designed for 120V into a 240V circuit, it’s gonna pop.
If you wire two of them in series, half of the voltage will drop across the first, and half across the second so they will both see 120V. Let’s say their resistance is 72Ω. Due to V=IR, the current will be (240/2)/72 (half the voltage because their in series divided by the resistance) that’s 1.667 amps. Power is P=IV so 120*1.667 = 200 watts. The current that goes through the first one has no choice but to go through the second bulb too. Which makes sense because it has the same resistance and the same voltage drop. This means each bulb uses 200 watts and the source has to provide 400 watts (1.667 amps at 240V)
If we, instead, wire the bulbs in parallel, they can only take 120 V. Since both the hot and common are the same for both, they have to see the same voltage drop (120V on their hot end and 0V on the common) we already figured out that each one uses 1.667 amps (and 200 watts) when provided with 120V, but the current that passes through the first bulb can’t reverse and also go through the second bulb since their in parallel. So the power source has to provide double the current so 1.667 amps goes to each bulb. That means 3.333 amps comes from the 120V source. Power is still volts times amps so 120*3.333 = 400 watts. It’s still the same power load whether their tied in series at double the voltage or in parallel at the voltage each bulb was rated for.
Now replace every instance of the word bulb with coil. The main difference is they don’t have a resistance per se. It’s called impedance and it depends on the frequency of the source (typically 60 Hz in America and 50 Hz abroad.) Each coil is rated for a voltage. If you put them in series, together they’ll soak up twice the voltage. The other difference has to do with 3-phase vs 1-phase (or split phase, but same diff).
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