Three Phase Polar Math question

[SaltySteve PE]

I can't for the life of me figure out how to get 7480<-21.2. It's a step in an example circuit analysis problem from School of PE.

Polar math is kicking my butt at the moment. Cant anyone help me understand how to work this.

-Steve  

 

[DLD PE]

When I enter what you posted into my calculator, I get 784.7<42.9, so something is amiss.  Would you mind posting the entire problem?

 

[SaltySteve PE]

At least I'm not crazy. I got that 784.7<42.9 as well. Here's the whole example. My only issue is that they did the example this was as well as with another method and came up to the same 13KV

 

[DLD PE]

Check your units.  For VaA you're multiplying amps times your impedence, which gives you volts.  VAN is in kV, so when you add the two in your previous question, you need to multiply  VAN x 10^3 so it's in volts before you add it to VaN.

 

[DLD PE]

View attachment 20190913072612457.pdf

See attached.  I thought this problem looked familiar.  It's #111 from the NCEES practice exam.

 

[SaltySteve PE]

Thank you so much.

That was breaking me.

 

[DLD PE]

No problem at all!