hey guys
can you guys give me a tip on this? your primary voltage is tap at 480v . you have 4 taps at 2-1/2% FCBN intervals and 2taps at 2-1/2% FCAN. The building 480v voltage is not true and is at 460v. I need the secondary voltage at 208v. With my 460v building tap at 480, Im not getting 208v off the secondary side. So I would have to change the primary taps to compensate for the building voltage. This is a test question I had on journeyman test.
1)2-1/2 FCBN
2)2-1/2 FCAN
3)5% FCAN
4)5% FCBN
5)7% FCBN
I did the problem and came out with these voltages
2.5 %fcbn 0f 480 is 468v
5%fcbn of 480 is 456V
the ratio of 460 to 208 v is 2.211/1
so what I did was
at 2.5% of 480 is 468v/2.211(ratio)= 211v secondary
at 5% of 480 is 456v/2.211(ratio)=206v secodary
What voltage should I use for the secondary that is suppose to be at 208v? Both calculation came higher or lower voltages. Should I go with higher or the lower voltage from the calulation?
can you guys give me a tip on this? your primary voltage is tap at 480v . you have 4 taps at 2-1/2% FCBN intervals and 2taps at 2-1/2% FCAN. The building 480v voltage is not true and is at 460v. I need the secondary voltage at 208v. With my 460v building tap at 480, Im not getting 208v off the secondary side. So I would have to change the primary taps to compensate for the building voltage. This is a test question I had on journeyman test.
1)2-1/2 FCBN
2)2-1/2 FCAN
3)5% FCAN
4)5% FCBN
5)7% FCBN
I did the problem and came out with these voltages
2.5 %fcbn 0f 480 is 468v
5%fcbn of 480 is 456V
the ratio of 460 to 208 v is 2.211/1
so what I did was
at 2.5% of 480 is 468v/2.211(ratio)= 211v secondary
at 5% of 480 is 456v/2.211(ratio)=206v secodary
What voltage should I use for the secondary that is suppose to be at 208v? Both calculation came higher or lower voltages. Should I go with higher or the lower voltage from the calulation?