RE: 12740Y/7200

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Brian" <brianv@xxxxxxxx>

The 7200V is the coil voltage from line to the neutral, the 12470 is the
line to line voltage. If you take the Line to line voltage and divide by the
sqrt of 3 that will give you the 7200. Which is 12470/ sqrt3 = 12470/1.732 =
7200 that 7200 is the coil voltage or the (single phase voltage). Gerry is
correct the name plate should say 12470V. Which is a common voltage
configuration.

Brian

-----Original Message-----
From: Tesla list [mailto:tesla@xxxxxxxxxx]
Sent: Thursday, December 28, 2006 10:26 PM
To: tesla@xxxxxxxxxx
Subject: Re: 12740Y/7200

Original poster: "Gerry  Reynolds" <gerryreynolds@xxxxxxxxxxxxx>

Hi Chip,

We'll see if I learned this correctly.  The 7200 means the voltage
across the HV bushings.  The 12740Y means the voltage from one Y leg
to the next Y leg.  If you assume each Y leg (from the center) is
7200V and each leg is 120 degrees phase different from the other two
legs, the math comes out to 12740V from leg to leg.  My PIG is marked
14400/24940Y for the HV side.
You may want to check your name plate again as I suspect the 12740 is
really 12470.

Gerry R


----- Original Message ----- From: "Tesla list" <tesla@xxxxxxxxxx>
To: <tesla@xxxxxxxxxx>
Sent: Thursday, December 28, 2006 9:05 PM
Subject: 12740Y/7200


>Original poster: "Chip Ford" <chipford@xxxxxxxxxxxxxx>
>
>What does it mean when a rating on a transformer says 12740Y/7200.
>Someone please explain this to me...Thanks...Chip Ford
>
>