Phase to Phase calc

[JasonMT]

Having issues with this question. If the phase to neutral in a three phase system is 2400 volts, the phase to phase voltage is approximately ? I came up with 4800 volts. The correct answer is 4150 volts. Could someone please explain. Much appreciated. Thanks.

 

[SparkyHC]

Phase to Phase and Phase to Neutral

Phase to Phase and Phase to Neutral

Consider 120V phase to Neutral and 208V phase to Phase...
and 277V phase to Neutral and 480V phase to Phase...
If you multiply the Phase to Neutral voltage times the square root of three (1.732) you get the
the Phase to Phase voltage. Now this is for a three phase system.
If single phase multiply by two (2)

 

[charlie b]

In any calculation involving a three phase system, the number 1.732 (i.e., the square root of 3) is going to show up somewhere. In your example, multiplying 2400 times 1.732, I come up with 4257 volts phase-to-phase. That is slightly different from what you are calling "the correct answer," but it is a matter of how accurately you wish to estimate a value for the square root of 3.

 

[GoldDigger]

For large values of 3, sqrt3 approaches 2.

Tapatalk!

 

[kwired]

Having issues with this question. If the phase to neutral in a three phase system is 2400 volts, the phase to phase voltage is approximately ? I came up with 4800 volts. The correct answer is 4150 volts. Could someone please explain. Much appreciated. Thanks.

For a Wye system multiply the phase to neutral value by the square root of 3. Should give you 4156.8. Most call this a 4160/2400 volt system.