Re: Transformer idle current

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Shaun Epp by way of Terry Fritz <teslalist-at-qwest-dot-net>" <scepp-at-mts-dot-net>

Yes,  The Inductive Reactance, XL,  of the Primary coil of the transformer
accounts for the majority of current limiting in standby.  XL = 2 x Pi x f x
L.  A good meter can measure L,  f  is 50 or 60Hz depending where you live.
there are some other losses like magnetization current and capacitance that
will change the current draw slightly, but mostly not noticeable.  I = V/XL
in this case.  To be more exact, you can also include the primary
resistance, measure the primary resistance and if it's within 100 time less
that the XL value then use I=V/ squareroot(R^2 + XL^2)

Shaun Epp
----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Wednesday, January 01, 2003 3:09 PM
Subject: Transformer idle current


 > Original poster: "Richard W. by way of Terry Fritz <teslalist-at-qwest-dot-net>"
<potluck-at-xmission-dot-com>
 >
 > Hi List,
 >
 > Is there a way to calculate a transformer's primary current with no load
on
 > the secondary?
 >
 > Rick W
 > Salt Lake
 >