I need help decoding transformer wiring

[smmcbride]

Hi guys,
This is my first post here but I've been lurking for a while. My first project is going to be a 2-ch amp so I decided to start by building a big power supply. Anyway, I picked up one of the 2kva transformers from brigarelectronics.com and, just my luck, it didn't come with a wiring diagram.

Is there a standard color scheme to the wiring in transformers or is each one different? I checked mine out with my multimeter and there appear to be three groups of three large guage wires connected together. Since it's 120/240 compatible I would assume that two of the groups need to be connected in parallel for the input side and the third would be the output. Is this correct? The colors for each group are:

Black - Grey - Green
White - Purple - Blue
Red - Red - Yellow

From the wiring is there any way to know which groups are on which side and which wire in each group belongs to which rail(pos, neg, neutral)?

Thanks
Shawn

[RichardH]

This doesn't totally answer your question, but it's a helpful page all the same:
http://www.plitron.com/pages/Products/Std/schemati.htm

[SY]

R-R-Y is almost certainly your secondary. To confirm the wiring of the primary, use a continuity meter to confirm the groupings, then inject a small voltage into the secondary while measuring the voltage coming out of the other groups to determine the proper primary wiring.

[Michael Rothacher]

Once you've identified the secondaries:

Newbe v. simple Transformer question

These guys provided very good explanations.

[smmcbride]

Thanks for the links and the info. I'll treat the red-yellow-red combo as the secondary and see what I get on the other lines.

Shawn