Kva vs. Kwatts

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They are not the same, and KVA cannot ever be smaller than KW. So the simplest answer is that they give you the value that is higher: the KVA value. Another answer is that the KVA rating (of any component, not just transformers) is based on the ability of the component to reject heat to its surroundings. That gives all components a common basis for comparison of their ratings.

Explaining the difference between ?Real Power (KW),? and ?Reactive Power (KVAR),? and ?Apparent Power (KVA),? is hard to do in this type of forum format. Perhaps someone can find a link to a site that explains such things in beginner?s terms?

Welcome to the forum. There?s lots to learn here.
 
As for beginner's terms: there are two types of power a transformer must provide, real power (watts) and reactive power (vars) and the transformer must provide the vector sum of the two (volt amps).

For an analogy, the real power (watts) is essentially the productive power. Think of it like real power is the soft drink in a glass, the reactive power is the foam, and the transformer is the glass that has to hold both foam and liquid (reactive and real power).

[edit: see the following notes from a class I taught]

kVA-kvar-kW.jpg
 
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rattus said:
Hires, Woosies, A&W, Stewarts, Webers, Dr. Brown's?
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A&W when I have to. DrP is my choice but my target audience had a better chance of staying awake if they saw words like "beer" every now and then during my schpeel.
 
If you hold the glass of root beer in the middle, can you say you have two glasses of root beer 180 degrees apart?
 
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engy said:
If you hold the glass of root beer in the middle, can you say you have two glasses of root beer with a 180 degree difference?
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engy said:
If you hold the glass of root beer in the middle, can you say you have two glasses of root beer 180 degrees apart?
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If the sides are straight, and I pinch the glass shut in the middle, and the glass has the same type opening on both ends, then yes, they are 180 degrees apart.

[edit: For a 180 degree difference, I would need some kind of heating element and thermal barrier in the middle]
 
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the productive power

the productive power

If you ship a refrigerator in a crate, you pay to ship the weight of the fridge and the weight of the crate. The crate you pay for is reactive power.
 
Lxnxjxhx said:
If you ship a refrigerator in a crate, you pay to ship the weight of the fridge and the weight of the crate. The crate you pay for is reactive power.
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Good analogy. I think I'll steal that if you don't mind.:smile:
 
mivey said:
A&W when I have to. DrP is my choice but my target audience had a better chance of staying awake if they saw words like "beer" every now and then during my schpeel.
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You now have my attention!! :0)
 
I'll steal that. . .

I'll steal that. . .

The teacher who told me that is probably dead by now, so gaw' 'head, but I can't guarantee that his descendents won't sue. . .
 
Lxnxjxhx said:
If you ship a refrigerator in a crate, you pay to ship the weight of the fridge and the weight of the crate. The crate you pay for is reactive power.
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I bought this huge bag of chips at the store, opened it up, and half the bag was empty !
So do you think I have a problem with potato chip VARs ?

I'm thinking I have about a 50% potato chip factor. . Should I attach a couple capacitors to the next bag before I open it up to correct my problem ?


.
 
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half the bag was empty

half the bag was empty

The standard disclaimer is "Some settling of the contents may occur."

If they dropped the fridge and crushed it and the crate, I guess the movers could say the same thing.
 
dnem said:
I bought this huge bag of chips at the store, opened it up, and half the bag was empty !
So do you think I have a problem with potato chip VARs ?

I'm thinking I have about a 50% potato chip factor. . Should I attach a couple capacitors to the next bag before I open it up to correct my problem ?


.
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Not sure if its true but I was told of a company that was trying to come up with ways to tell if a bag had chips or just air. After much study of resistance measurements, etc, they just decided to put a fan/air on the line and blast the empty bag off. You must have gotten a bag that was only blown 1/2 way off the line.:smile:

The only way I know of to verify that you are getting ripped off is when the bag has something like "new and improved" on it.
 
dnem said:
I bought this huge bag of chips at the store, opened it up, and half the bag was empty !
So do you think I have a problem with potato chip VARs ?

I'm thinking I have about a 50% potato chip factor. . Should I attach a couple capacitors to the next bag before I open it up to correct my problem ?


.
Click to expand...


Buy Pringles next time!:D
 
99 bottles of beer

99 bottles of beer

Two glass's of beer are alway 180 degrees apart. It's the third glass that changes the sin, cosin and radius of the phase model. SUMB (snickering under my breath)
 
dwcaveney said:
Two glass's of beer are alway 180 degrees apart. It's the third glass that changes the sin, cosin and radius of the phase model. SUMB (snickering under my breath)
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Don't forget about two-phase beer which is 90 degrees apart or the two-glass "why" (non-alcoholic) beer that is 120 degrees apart.
 
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