difference in motor and transformer used for 230V, 60Hz system and 415V, 50Hz system

[elecengg010]

What is the difference in the design of transformer and motor (core and windings) in US (230V,60Hz) and India (415V, 50Hz)?

 

[Tofeil]

The following formula is key for your question:
E=4.44*N*f*A*B
E= electro-motive force
N= turn of winding
f=frequency
B=magnetic flux density
A=unit of area

if f1>f2 and E2>E1 then it must be n1<n2 or A2<A1

therefore US devices are larger(A1>A2)

 

[elecengg010]

According to this equation
(N*A*B)[sub]US[/sub] < (N*A*B)[sub]India[/sub]
If B and N are same
then A[sub]US[/sub] < A[sub]India[/sub]
therefor U.S. devices are smaller

 

[Tofeil]

I maked a mistake in line 8 for comparing N.
I think, N can be determined by A, because The amount of copper usually is same, then for example if A2>A1 then N2<N1
(N)us<(N)ind then (A)us>(A)ind

 

[KllrWolf]

From the motor point of view, the 230/60 would be smaller than the 415/50. The problem with the 415/50 is the Volts/Hz ratio. A motor we design to operate at either 380/50 or 460/60 would overheat at 415/50. I would hazard a guess by talks with some of our customers that deal with the various places, but the 415/50 Hz combination is something that causes a bit more money and time spent on design and parts purchase for a given system.

 

[waross]

From the motor point of view, the 230/60 would be smaller than the 415/50.

In general, 50 Hz equipment is larger than 60 Hz equipment of the same rating. The converse is that 60 Hz equipment used on 50 Hz has a reduced capacity. The ratio is 5:6 or 6:5 and has to do with increased inductive reactance at higher frequencies allowing a higher Volts per Hz ratio at higher frequencies. This allows a higher voltage without magnetic saturation and so a higher ultimate VA.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[KllrWolf]

waross, you are correct taht 50 Hz is bigger than 60 Hz. The point I failed to make is that when we have to deal with 415/50, those motors are larger than the the standard ratio motors of the same frequency, i.e. 380/50 would be smaller than the 415/50. Heck, most of the time we can build a 380/50 with a 1.15 s.f. smaller (and thus cheaper) than a 415/50 with 1.0 s.f. of the same Hp rating. This last part may not be normal to air cooled motors, but unique to the specific type of water filled motors we make.