Welcome to Tesla Motors Club
Discuss Tesla's Model S, Model 3, Model X, Model Y, Cybertruck, Roadster and More.
Register

Is there a 208 WYE 3 phase charging option?

This site may earn commission on affiliate links.
Your arithmetic checks out (once I parsed the lack of parentheses) although I don't understand why.

I'm under the impression that L-L of V voltage each in a 3 phase config have an RMS voltage of V*sqrt(3)

When a load is using 3 phase power (where all the wires are hooked up, not in an L-L config like you see with 208Y/120V), you have to remember that all the L's are being used.

So your equation needs to be:

((L-L voltage) / sqrt(3)) * (amps) * 3

Example:

Supercharger-cabinet-label_600.jpg


Tesla specs it to 192 amps. We also know that (at least in the US) the superchargers can go up to 150kW now. How do we get there?

(480V / sqrt(3)) * 192 * 3 = ~159kW

(This also explains why we may not see 150kW in Europe, as a 400/230 system can only go up to 133kW, so Tesla would have to modify their gear to draw more than 192 amps.
 
When a load is using 3 phase power (where all the wires are hooked up, not in an L-L config like you see with 208Y/120V), you have to remember that all the L's are being used.
OH ....

What is the V(rms) of each line ?

I'm stuck in a rut of tying to understand this via vector addition. Do I extend the addition to 3 vectors, each pi/3 out of phase from each other ? If so the vector result eyeballs out to ~ 2 * one line's RMS voltage

I appreciate your posts very much. Thanks !
 
Last edited:
OH ....

What is the V(rms) of each line ?

I'm stuck in a rut of tying to understand this via vector addition. Do I extend the addition to 3 vectors, each pi/3 out of phase from each other ? If so the vector result eyeballs out to ~ 2 * one line's RMS voltage

I appreciate your posts very much. Thanks !
Understanding Three Phase Voltage | Pacific Power Source

Each phase is 120 degrees (2pi/3) off the others. So if L-N is 120 each, phase to phase is: 120*2*sin(120) = 208.
Sin(120) = sqrt(3)/2, so 2 * sin(120) = 2*sqrt(3)/2 = sqrt(3).
 
  • Informative
Reactions: EfficientWatts
I believe that is 277 L-N Wye feed with a 480 L-L. The version 2 charges are made of 12 vehicle chargers set up with 4 on each phase to neutral to provide the 277V to the charger and minimize Neutral current.
If I think of this as simply 3 wires, each with 277 V(rms) L-N the arithmetic works:

277 Volts
192 Amps
3 wires
----
159 kW

Where does the Wye come into this ?
 
If I think of this as simply 3 wires, each with 277 V(rms) L-N the arithmetic works:

277 Volts
192 Amps
3 wires
----
159 kW

Where does the Wye come into this ?

That looks right.
Wye (Y) is just the transformer setup with three phases and a neutral as compared to Delta (triangle) which may possibly have a split neutral on only one phase. In this case, with the three phases in balance, the neutral does not carry any current.
 
(This also explains why we may not see 150kW in Europe, as a 400/230 system can only go up to 133kW, so Tesla would have to modify their gear to draw more than 192 amps.
I believe in countries that don't offer 277Y480V service from the utility, Tesla usually installs their own buck or boost transformer to get the nominal voltage to 480V. I have seen this in pictures from Hong Kong (220Y380V) and Canada (347Y600V). That way, the cabinets can still draw their spec "up to 192A".
 
I believe in countries that don't offer 277Y480V service from the utility, Tesla usually installs their own buck or boost transformer to get the nominal voltage to 480V. I have seen this in pictures from Hong Kong (220Y380V) and Canada (347Y600V). That way, the cabinets can still draw their spec "up to 192A".
Also, if you have a Delta-Y or Y-Delta transformer, this helps a little with load balancing (which is the main concern that started this thread). I don't know if Tesla takes advantage of this for their own purposes.