Electrical Engineering - Three-Phase Systems in Power Applications - Discussion
Discussion Forum : Three-Phase Systems in Power Applications - General Questions (Q.No. 9)
9.
A two-phase generator is connected to two 90 
load resistors. Each coil generates 120 V ac. A common neutral line exists. How much current flows through the common neutral line?
load resistors. Each coil generates 120 V ac. A common neutral line exists. How much current flows through the common neutral line?Discussion:
63 comments Page 3 of 7.
Vjagannadharao said:
10 years ago
Resistance will be 45.
And I = V/R.
V = 40, i = 120.
I = 120/45 = 2. 66 A a write method.
Current neutral wire is 1.33+1.33 = 2.66 A.
Then I = V/R = 2.66 A.
And I = V/R.
V = 40, i = 120.
I = 120/45 = 2. 66 A a write method.
Current neutral wire is 1.33+1.33 = 2.66 A.
Then I = V/R = 2.66 A.
Naveen BM said:
8 years ago
Since it is AC we should take RMS voltage into consideration. The RMS voltage = (Peak Voltage/SquareRoot(120)).
Hence the current=(2*(squareRoot(120)))/90==1.88.
Hence the current=(2*(squareRoot(120)))/90==1.88.
Somnath said:
1 decade ago
I think it's 2.66.
2 phase generator. So connect load of 2*90 ohm resistance in parallel.
Resultant resistance will be 45.
Then I = V/R.
= 120/45 = 2.66 A.
2 phase generator. So connect load of 2*90 ohm resistance in parallel.
Resultant resistance will be 45.
Then I = V/R.
= 120/45 = 2.66 A.
Palthur said:
1 decade ago
In a two phase system voltages are displaced apart from each other by 90 degree so resultant of 2 currents flow through the neutral wire which is 1.88 A.
Sasikumar paramasivam said:
8 years ago
The current in each phase is 120/90 = 1.33a.
For two-phase system, the resultant current at the common line is root(2) of phase current which is 1.88a.
For two-phase system, the resultant current at the common line is root(2) of phase current which is 1.88a.
Chandrima said:
10 years ago
Answer should be 1.88 amp.
V/i = 1.33 amp, current flowing through neutral 2*1.33 = 2.66, but RMS value of the current will be 2.66/sqrt2 = 1.88 amp.
V/i = 1.33 amp, current flowing through neutral 2*1.33 = 2.66, but RMS value of the current will be 2.66/sqrt2 = 1.88 amp.
Alankar said:
1 decade ago
Here the answer will be 2. 66. The guys saying that for balance load no current follows through the neutral should think that neutral is common here.
Subhankar said:
1 decade ago
The guys saying that for balance load no current follows through the neutral should think that neutral is common here. So answer 2.66.
Hami said:
1 decade ago
I think 1.88 A is right answer. Because there is common neutral wire which means 1.33 A. After multiplying with 1.141, we get 1.88 A.
Parth Vaghela said:
3 years ago
The circuit will be balanced due to the same amount of load on both phases and so the current through the neutral wire must be zero.
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