3 phase to single phase calculation

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engrkira

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Location
Philippines
Good day, I do have a question about generators. Let us say I have 100 KVA, 3 phase, 440 Volts with power factor of 0.8 and the I want to convert it into single phase with 220 Volts. What would be the KVA equivalent in single phase?

Can someone provide with calculations or other suggestions?

Thank you so much
 

Smart $

Esteemed Member
Location
Ohio
Good day, I do have a question about generators. Let us say I have 100 KVA, 3 phase, 440 Volts with power factor of 0.8 and the I want to convert it into single phase with 220 Volts. What would be the KVA equivalent in single phase?

Can someone provide with calculations or other suggestions?

Thank you so much
How do you plan to convert?

kVAIN × Efficiency = kVAOUT
 

topgone

Senior Member
If your unit is a 12-lead generator, recommend to wire into zig-zag.

Your maximum line load amps will be 151.52A. That will give you a total single-phase capacity of 53 kW at pf=0.8. (26.7 kW on each line to neutral).
 

engrkira

Member
Location
Philippines
If your unit is a 12-lead generator, recommend to wire into zig-zag.

Your maximum line load amps will be 151.52A. That will give you a total single-phase capacity of 53 kW at pf=0.8. (26.7 kW on each line to neutral).

Sir how do you get the total single phase capacity?
 

topgone

Senior Member
Sir how do you get the total single phase capacity?
2008-11-04_223629_ZIGZAG.jpg
With 100 kVA, 440V, 3-phase, your rated phase current will be 75.52 amperes (each phase will carry 1/3 of the total balanced load = 100/3 = 33.33kVA).
That current is actually the rating of each of the 440-V, series-connected windings.
Wire those coils parallel and then you have a rating of twice the rated amps =151.52 amperes!
This value will be the maximum current on either of your line-to-neutral loads. L1- N = load 1; L2-N = load 2
Your neutral will have no current if your single-phase loads are balanced (equal). 151.52 x 220 x 0.8 = 26.7 kW. Since you have 2- single phase loads, your total load is 53.3 kW. 53.3kW/80kW max = 66% of 3-phase capacity!
 

engrkira

Member
Location
Philippines
View attachment 15377
With 100 kVA, 440V, 3-phase, your rated phase current will be 75.52 amperes (each phase will carry 1/3 of the total balanced load = 100/3 = 33.33kVA).
That current is actually the rating of each of the 440-V, series-connected windings.
Wire those coils parallel and then you have a rating of twice the rated amps =151.52 amperes!
This value will be the maximum current on either of your line-to-neutral loads. L1- N = load 1; L2-N = load 2
Your neutral will have no current if your single-phase loads are balanced (equal). 151.52 x 220 x 0.8 = 26.7 kW. Since you have 2- single phase loads, your total load is 53.3 kW. 53.3kW/80kW max = 66% of 3-phase capacity!




Sir, does it matter if I use wye or delta connection?
 

topgone

Senior Member
Sir, does it matter if I use wye or delta connection?

If you don't want to tinker with the generator terminal re-configuration, whatever suits you-->delta or wye will do. What's important is that either of the three "phase currents" of your generator does not exceed the rated amps.
 
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