Delta or Wye

[ray schrauwen]

Something to do with shorter length of wire for power to travel through, less resistance..?

[supafastsupra2]

yup, V=IR. At a given voltage, less resistance= more amperage. Take a look at the Delta and Wye diagrams on top and focus on the Resistances. Let's say for example resistances Ra,Rb, Rc, R1,R2, and R3 are all 3ohms and our voltage is 15 volts. R of a series circuit is simply R1+R2+R3... so on and so forth. R of a parallel circuit is 1/R=1/R1+1/R2+1/R3....etc.

So for the delta wind, the effective resistance of a single phase going off the equations is 1/R=1/6+1/3, or 2ohms. On the Wye wind you simply get 6ohms. So while the delta wind pulls 7.5A (using V=IR) the wye only uses 2.5A. This also means that a delta wind motor of similar kv equivelancy to a wye should handle more wattage since you're passing current through a much lower resistance.

To add to Fluid's explanation of Delta wind motor having more torque, Power(W)=(Torque)(2pi)(rotations/second), so using the previous situation of same kv delta and wye motors, the one that consumes more power (watts) will have greater torque. Hopefully this helps clarify how it all works

[Diesel6401]

Can a mod make this a "sticky" PLEASE?!?

[ray schrauwen]

Sticky

That would be nice until I can memorize it.

[jcald2000]

Amps = torque

[Diesel6401]

Amps = torque

Way off, thats not even remotely true IMHO take 2 motor same size and length 3674 one 3000kv one 1500kv same voltage same prop, the higher kv is gonna pull more amps, it will have higher rpms, but less torque. The wattage would be higher also amps x volts = watts. Doesn't mean it has more torque though. With that theory I can stick a insanely high kv motor in a larger hull and because the amps draw is so high that means it has more torque?

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[znus]

Maybe the other way around is closer to the truth, although you shouldn't mix electric motors with gas engines Voltage = torqe, Amps = horse power.

A 1500 kv might not be insane but it's strong and reliable, like a diesel.
A 4000 kv is totally insane but heats up fast and and eats a lot of amps = F1 engine

Boats like diesel engines. Just look at the commercial fleet.

[Boaterguy]

volts*amps= watts
1hp= ~750W
what i still am missing about brushless motors is multiple poles, is it just the diagrams in the first post on top of each other and then offset ? so there are 6 outpust instead of 3 on the wye wind?

[jcald2000]

Sorry Diesel, Thats not what my eagle tree has been telling me for 10 years, but to each his own.

[Gimp]

Great information here, thanks for the explanation.

My new TP 4082 2200kV motor is a 6D wind. I know D's are supposed to have low timing, but what's the range?

[ray schrauwen]

Five to start, ten at most.

[Gimp]

Thanks Ray. It's set to 3.75 and my next option is 7.something (T180), for sport boating should I just leave it or try the 7.something?

[drwayne]

Out here in the 'real world' of industrial application.. large motors have delta start followed by wye run switching circuits.
Delta have abundant torque from stall (at low rpm ) , same wind Wye are better for higher rpm and control...

Pole explanations can mimic cylinders in an engine..the more poles, the more times the mag rotor is 'fired' per revolution..
A 2 pole motor is more likely to stall at low rpm/high load than a multiple pole motor.

W

[ray schrauwen]

So, maybe over simplified buuut, Y winds accellerate faster to top speed than D winds and D winds can run heavier loads for longer times but, don't accelerate as quickly? Also, it's more work to get the D wind (more heat & amps) up to full rpm than a Y wind?

[drwayne]

So, maybe over simplified buuut, Y winds accellerate faster to top speed than D winds and D winds can run heavier loads for longer times but, don't accelerate as quickly? Also, it's more work to get the D wind (more heat & amps) up to full rpm than a Y wind?

err, ahh...
Bloke here runs petrol motors.. claims his the fastest 'ever' because can free rev to 19k5 rpm... although reckons his props must be poor because onwater he averages 16k5...
Higher torque motor would offer higher rpm support under load... although the wye motor would have run longer for the same total mAh consumption.2
Are your boats leaders, or followers ?

My light hulls use wye.. heavier get delta.

end of day it's the motor/prop combination you choose that determines final outcomes... and both DorY are suitable... to the right wheel ..