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Question
If single phase voltage level is 230V than why three phase 
voltage level is not 660V ?, but it is only 440V.
 Question Submitted By :: Electrical-Engineering
I also faced this Question!!     Answer Posted By  
 
Answer
# 1
Single Phase voltage = Phase voltage / sqroot of 3 
Is This Answer Correct ?    166 Yes 37 No
Max
 
Answer
# 2
In single phase

single phase voltage =phase voltage , but in three phase
line voltage =sq. root of phase voltage (i.e V
line=1.732x240 =415 vol.)
 
Is This Answer Correct ?    100 Yes 15 No
Ashok Kumar
 
 
 
Answer
# 3
because the voltage is measured between the two terminals
only in 3 phase we are measuring it between 2 lines that is
why it is 440 and not 660
 
Is This Answer Correct ?    88 Yes 34 No
Sunny
 
Answer
# 4
In single phase case; 220 v is potential difference between phase and neutral, whereas in three phase case potential difference between any two phase terminals will be around 415 v. All three lines show a potential difference of aprox 220 v with respect to neutral but are but are apart from each other by an angle of 120 degree (phase difference) so will exhibit almost double potential difference between any two line terminals. So for all practical purposes potential difference between any two phase terminals will be around 415v. However for power calculations etc we multiply 415 with squareroot of 3 to get actual total line voltage which is a sine function of phase angle between them. 
Is This Answer Correct ?    28 Yes 5 No
S Singh
 
Answer
# 5
In three phase power line, each phase is 120 degree from the other phase.therefore, when we draw a graph of phases then two phases have positive values then at the same time the third one has negative value so we can calculate and use only two phases at a time.all three phases changes their position every time so the two phase may be phases 1 &2/phases 1&3 or phases 2&3 gives the values and at the same times phase 3 or 2 or 1 will be at negative interval respectively so cannot be calculated or contribute the value. that's the reason we use 440v instead of 660v. 
Is This Answer Correct ?    3 Yes 0 No
M.ubaidullah Khan
 
Answer
# 6
The question is incorrect, the line voltage is not 440v, it
will be 400v if your single phase is at 230v.
Reason why its 400v is because if you put a voltmeter across
both live phase voltages, it show 400v. But you will need a
picture showing waveforms to explain it properly.
 
Is This Answer Correct ?    2 Yes 0 No
Pete
 
Answer
# 7
Voltage is nothing but potential difference, so we can take
only 2 objects if we want to measure the difference between
them. So we always measure this difference of potential
between 2 not 3.
 
Is This Answer Correct ?    18 Yes 18 No
Bbhanj
 
Answer
# 8
that is where frequency does matter, because with frequency one of the three phase become neutral after a timeperiod. so for that reason at a moment two phases are showing 440v in pakistan). 
Is This Answer Correct ?    2 Yes 2 No
Jawad 923218471617
 
Answer
# 9
3 phase doesnot means 230+230+230

in three phase three lines carry same voltage but displaced
in time by 120* that is we obtain V (L-L)=400kv
 
Is This Answer Correct ?    21 Yes 33 No
Percy
 
Answer
# 10
because
single phase =phase voltage /square root of three
and the other reason is that the two terminals
 
Is This Answer Correct ?    8 Yes 25 No
Hemantpandey
 

 
 
 
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