And Now MVaR in words of one sylable or less 6

[JJayG]

Here's one for all of you clever electrical chappies out there.
Imagine trying to explain MVaRs to a new starter, ie. in the simplest way possible.
All analogies welcome (except maybe the horse and barge one).
Points may be awarded for creativity but deducted for over technicality.
This has always been one of those questions that,(along with what is entropy?)has been a source of consternation in power stations since Michael Faraday was a lad.
Go On, you know you want to............

JJ

 

[rbulsara]

Facts can be confusing..

Rafiq Bulsara

http://www.srengineersct.com

 

[waross]

I am confused, I understood that the A was capitalized to show respect for André-Marie Ampère. Now I am told that is only the case if the A?amperes are in phase with The Volts, even though an instrument designed to measure Amperes only has no idea whatsoever as to the Amperes relationship to the Volts that cause the Amps to flow. Is this a reflection of some historical antagonism between Ampere and Voltaire?
But what plays in Vegas stays in Vegas and what the french do to their own should stay in france.
No that's not a typo, de-capitalizing Ampere seems a little reactionary and the new rules say that reactionary entities lose their capitalization.
On a little more serious note; (emphasis on little)
Many years ago I learned a little bit of English grammar. One subject I dimly remember is abbreviation. I seem to remember that abbreviations shall be capitalized.
AVR: automatic voltage regulator, PMG: permanent magnet generator, CT: current transformer, PT: potential transformer, VAR: Volt Amps reactive, oops.
Although some may prefer to use the more recent name,I prefer the full descriptive name, Volt Amps reactive, and following the rules of English grammar abbreviate this to VAR.
Should a German, an Italian, or a Russian challenge my use of the rules of the English grammar I would be offended. Should a Francophone challenge my or demand that I change my habits, Oh well, that's just the French. Look at the reactionary treatment of the memory poor André-Marie Ampère!
You may say var. When I say VAR I am abbreviating Volt Amps reactive. grin Now let's head for the pub and work on the beer analogy. VAR - Very Agreeable Refreshment.

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

 

[Skogsgurra]

OK. I give up - again. Beer wins. Hands down.

(You didn't get the unit multiplication thing. Think about it. It makes sense. But now for the beers!)

Gunnar Englund

http://www.gke.org

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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...

 

[jghrist]

I might as well put in my two cents worth. The reactive power unit var is more like the real power unit watt. It is not an acronym like VA or an abbreviation of a unit like V so it is not capitalized. I've got to admit that the argument would be stronger if there were a Ferdinand Var out there somewhere who invented the electromagnet.

I also vote for beer.

 

[rbulsara]

That would make the argument even weaker, if it is indeed named after Ferdinand Var, then it should be called (named) Var and nor var. IEC/SI even says that var is the Name and the unit of reactive power. As far as I know, the name is still reactive power.

..keep going with beer! I will be designated driver.

Rafiq Bulsara

http://www.srengineersct.com

 

[ScottyUK]

If this keeps going I'm quitting the beer and hitting the whisky!


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If we learn from our mistakes I'm getting a great education!

 

[rbulsara]

I bring the white flag and a jar of ice!!

Rafiq Bulsara

http://www.srengineersct.com

 

[edison123]

All this war over VAR ???

You guys must be really drunk.

BTW, I'm all for VAR, not some pansy var.

Muthu

http://www.edison.co.in

 

[ScottyUK]

Muthu,

It's 0225hrs here. My litle girl has a cold and can't sleep, so I'm not allowed to sleep either. That whisky is looking more tempting by the minute!


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If we learn from our mistakes I'm getting a great education!

 

[edison123]

Hi Scotty

Hope your little girl gets better soon. Sick children take a lot out of you. Been there, done that. My kids are all grown up and I just exchanged one set of problems for another. Now the older problem doesn't look not so intimidating anymore.

PS: In your frustration, don't give the whiskey to the daughter.

Muthu

http://www.edison.co.in

 

[waross]

My little guy will be 4 next month. We talk on the phone a lot. When he is sick, I can just worry and get telephone updates from his mother. Sympathy and a prayer for your daughter.
Yours
Bill

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

 

[waross]

Edison;
I like your description, pansy var. The governor of California would probably call them "Girlie vars."

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

 

[sibeen]

I must add, from an antipodean point of view, vars just sounds so, errr...I'm sorry, I feel a bit queasy.

 

[electricpete]

All this war over VAR ???

var wars?

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[waross]

We're still working on the beer and froth analogy. Another round please.

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

 

[rbulsara]

Bill:

Since you asked for it, here is some information from a more authentic source, the IEC website.

Which clarifies the following:
The name var is not related to a person's name. It in fact stands for volt ampere reactive power and the unit is also var. (not that it is widely accepted or all have to agree to it).

Also there is an official conversion factor: 1 var= 1 V.A

(How original and useful! Conversion factor for an arbitrarily invented unit!)

So what is wrong with writing a name in Upper case? and units can still be VA , using the conversion factor!)

Then there is a Statement by J.H. Dellinger (U.S. Bureau of Standards) in 1916, which is even true today.

“In conclusion, this study has shown that the international system, based upon representing the electromagnetic system, is a convenient and satisfactory system of units for the purposes of electric and magnetic measurements. Proposed changes in some or all of the units do not appear to offer advantages such as to justify the confusion and inconvenience of changing the units as ordinarily used.”


The links are:

http://www.iec.ch/zone/si/si_statements.htm

http://www.iec.ch/zone/si/si_elecmag.htm

By the way, IEC has also created a storm or a debate in IT world as well by creating some arbitrary units like 1KB=1000 bytes where as the conventional wisdom and fact is 1024. (or something like that).


Rafiq Bulsara

http://www.srengineersct.com

 

[Skogsgurra]

The reason for this is not obvious for those that do not use SI units.

The beauty with SI units is that they can be used to check validity of equations, among other things. But, if you use an arbitrary addition to the "pure" SI units, then validity check will not work. And since W and VA are reserved for active and apparent power, there is a problem with reactive power. Using VAR or VAr will not work, simply because the "R" or "r" doesn't fit when doing "unit algebra". That is why the unit var was defined. The dimension of var is still VA.

I think that you should accept that scientific work needs more than arbitray conventions. But use VAr or vaR or VaR or whatever you feel like. But be prepared to meet one or two elevated eyebrow now and then.



Gunnar Englund

http://www.gke.org

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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...

 

[ScottyUK]

Hi Gunnar,

I am trying to follow your logic - I promise, I really am - but I am so far failing. Keep trying!


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If we learn from our mistakes I'm getting a great education!

 

[Skogsgurra]

No Scotty, I will not. I just explained why the var unit was created and why it is used in natural sciences. I am not trying to force you or anyone else to use it. No way.

(Is it the "unit algebra" AKA "dimension analysis" that you don't understand? I shall google to find a few URLs for you, if that is the case).

Gunnar Englund

http://www.gke.org

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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...

 

[electricpete]

I can see the logic which does not admit separate units for VA and VAR. However the same logic also should not admit different units for power (watts) and apparent power (va). This also follows from dimensional analysis of:
S = P * P.F.
If P.F. is unitless, then S must have the same dimension as P.



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