Three-Phase Circuit Problem- Solve It and Get A Discount on My Books

[Cram For The PE]

I will give the first person to solve this problem a discount on my books. See Link for details.

http://cramforthepe.com/index.php/2020/09/14/three-phase-circuit-problem-solve-it-and-get-a-discount/

A three-phase un-grounded circuit with ABC rotation is connected to a resistive load as shown below.

Ra, Rb and Rc are each 22.5 ohms. Voltage Vc Fails open. An AC volt meter is placed as shown below to determine the voltage.

What will the voltmeter read?
Answer to nearest tenth. You must show how you got the answer.

 

[speakeelsy PE]

0V?

 

[Cram For The PE]

0V?

View attachment 18698

This is incorrect

 

[Orchid PE]

0V?

View attachment 18698

Why do you think you can split the 3-phase circuit up into three single-phase circuits?

 

[akyip]

Is the voltmeter voltage = 50 V by any chance?

 

[speakeelsy PE]

Why do you think you can split the 3-phase circuit up into three single-phase circuits?

It was more of an attempt at single phase equivalent circuits... Which didnt seem like it would work, but I'd also just read this White paper and 0 seemed like a reasonable answer for an open circuit. Ive never ran into this problem in the field as most of the 3 phase systems at my work are delta.

 

[DLD PE]

This was my attempt.  I got 173.2V but @akyip's answer looks like a good possibility too.