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Re: Pig Terminology (fwd)



---------- Forwarded message ----------
Date: Mon, 27 Apr 1998 09:25:20 -0700
From: Jim Lux <jimlux-at-earthlink-dot-net>
To: Tesla List <tesla-at-pupman-dot-com>
Subject: Re: Pig Terminology (fwd)


> 
> 
> ---------- Forwarded message ----------
> Date: Sun, 26 Apr 1998 20:22:54 -0700 (PDT)
> From: Michael Baumann <baumann-at-proton.llumc.edu>
> To: Tesla List <tesla-at-pupman-dot-com>
> Subject: Pig Terminology
> 
> Question:
> I have a description of a couple of pigs that are available, but I am
> confused, and would like to get a translation from those that are
> more familiar with the beast:
> Primary is listed as 14400/24940Y, 
The voltage in three phase power can be given as either Line to Line
(24940) or Line to neutral (14400). The two are in the ratio 1.73:1. You
also see this as 208/120.  The Y means that the winding is connected in Y,
as opposed to Delta. In Y (also spelled Wye) is where one end of each
winding is connected to a neutral, making a 4 wire system (Draw a diagram
and you'll see where the name comes from). Delta has the end of each
winding connected to the end of the next winding, forming a capital Greek
letter Delta, when you draw it.

there is an impeadance listed,
> and for taps, there are (+, -, N, J) listed.
> I am trying to translate this notation.
> Specifically: what is the 24940Y?
>               What are the various tap listing mean? 
>                  I assume - is none, but perhaps that is what N is?
N = Nominal?
> 
> Also, the possibility exists to pick up a 3KVA unit, in place of 
> the 5KVA.
> I am assuming the smaller unit would be easier to move about,
> but I want to make sure I can push it as hard as I  think I can.
> 
> the 3KVA unit could be run at as high as 6KVA, yes?\
You bet... That 3kVA is to run 40 years in the burning desert sun. 

> [Or should I just bite the bullet, and live with the larger
> size of the 5KVA unit?]
Well, that is really your decision.. The 5 kVA unit will weigh about 5/3
more than the 3 kVA unit (it really does basically scale as the power).
More power means you need more core, more copper, and more oil, and they
all go as the volume, so weight is roughly proportional to electrical
size.... There are economies of scale, so a 1 MVA transformer doesn't weigh
1000 times what a 1 kVA unit does, but substantially less (but still a
lot)).

>