How do I figure out what wires are what on a Westinghouse tv power transformer? Has 9 wire. 2 green, black/white, black/red, what looks to be tan, black/what looks to be tan, green/white, and black.

Usually the primary is on a pair of black wires. Perhaps you have a transformer that has taps on the primary to adjust for different line voltages. Or perhaps the color codes are just weird.

Here's what I would do. Get out the ohmmeter and find out what is connected to what. While you are at it, write down the resistance readings. Filament windings will have a very low resistance. A high voltage secondary will have a quite high resistance. Primary windings will be in the middle (if tapped, the main part of the primary will be in the middle). Then use a Variac or another transformer and apply something like 6 volts to the winding that seems most likely to be the primary. Now measure the voltages on all the other windings. If the measured voltages suggest that you do have the primary, apply a higher voltage and re-do the voltage readings. If things look good, apply 120 volts and see what you get.

Look for RTMA transformer codes under Hints & Kinks..............

That one doesn't appear to follow a standard color code. Could some of the wire colors be faded so badly they don't look the same as when new?

I agree that Tom's method of comparing resistance to what one would reasonably expect, then using a low voltage AC source to confirm, is the best and safest way to do this.

You could be right. I noticed earlier that the black wire is really blue.

I tried the resistance readings, but almost all of the sections are really low resistance. I did notice that 3 of the wires are connected.

Once I make it back from Ryans, I'll get a pic of the transformer and post the resistance readings.

None of the windings will have a high resistance, but some will be higher than others. On a transformer I have handy, the filament windings measure 0 ohms, the primary measures 1.2 ohms & the high voltage secondary measures 50 ohms end to end with the two halves measuring 24 ohms and 26 ohms.

The reason for doing the initial voltage testing by applying 6 volts is that you can apply that voltage to any winding.

Here's the transformer, all 10 pounds of it.



And a full size pic for more detail.

http://www.thevintageattic.net/gallery/displayimage.php?pid=275&fullsize=1