Unbalanced

Taking a practice exam and one of the questions states:

"What is the unbalanced current flowing in the neutral of this three-phase, four-wire, 480/277-volt system? "A"phase= 22amps "B"phase=39 amps "C"phase = 46 amps."

Answers a. 38.10 amps
b. 25.00 amps
c. 21.37 amps
d. 19.14 amps

It would be greatly appreciated if someone could remind me the formula to calculate what they are asking.

Go here for the formula:
[size=-1]www.mikeholt.com/documents/ freestuff/ElectricalFormulas.pdf

A squared + B squared + C squared = 4121
AB + BC + AC = 3664
Subtract = 457.
Square root of 457 is ???

Keith
[/size]

keithkyll said:

Go here for the formula:
[size=-1]www.mikeholt.com/documents/ freestuff/ElectricalFormulas.pdf

A squared + B squared + C squared = 4121
AB + BC + AC = 3664
Subtract = 457.
Square root of 457 is ???

Keith
[/size]

Click to expand...

I wasn't sure how to show the formula in text, but I'll try.

Take the square root of:
((A*A) + (B*B) + (C*C)) - ((A*B) + (B*C) + (C*A))

Keith

√(A²+B²+C²)-(AB+BC+AC)

One day I will figure out how to make the sqrt symbol extend over the rest.

This editor is screwy.

Ron...

  _____________________

√(a²+b²+c²)-(ab+bc+ac)

[ladder][size=4]
_____________________
[size=6]√[/size](a²+b²+c²)-(ab+bc+ac)
[/size][/ladder]


It is easier if you write this kind of stuff in a Word File using Courier... WITHOUT Tags! Don't add Tags until it looks good in the Word File.

When it looks good in the Word File, add the Tags and then copy-n-paste to the thread.

Then preview a couple of times... adding spaces as necessary to get the Underscore aligned.

cheater, but that works...reckon I will drink another MGD on that one.

Terry Woods said:

...Then preview a couple of times... adding spaces as necessary to get the Underscore aligned.

Click to expand...

Then RE-add the spaces that 'Preview Message' removed, before clicking 'Submit Message'...



-Eric