# Symmetrical components: phase voltages

In the following question on symmetrical components, the 11kV of the source is the line-to-line voltage. When using symmetrical components you want to be working with line-to-neutral voltage. Am I right in saying this? In the memo for this question the 11kV is devided by squareroot 3 in order to obtain the phase voltages. Initially I used the 11kV without dividing by squareroot 3. How would I determine which path to follow (divide or not by squareroot 3), by looking at this question? Is there a standard which I should always follow, or am I missing key words in the question which tells me exactly what to do?

I am fine with the rest of the question, I'm just confused in determining the phase voltages. Thank you

"A 11 kV source delivers power to a power system with terminal voltages at rated value. A fault occurs in the source and it causes the b-phase voltage Vbn of the source to fall to zero (not an open circuit). With the a-phase voltage Van of the source as the zero reference, calculate the sequence network voltages V0, V1 and V2."

• In addition to the question: It states that the terminal voltages are at rated value. Is it correct to say that the rating is 11kV and the terminal voltage are the voltages between lines a-b, b-c and c-a? In that case the 11kV will be line-to-line voltage which results in the phase voltage being 11kV divided by squareroot 3. – user3760399 Dec 3 '15 at 10:04
• yes.. in a 3 phase distribution network the voltage is usually stated as being phase to phase. – Spoon Dec 3 '15 at 13:14