Dual primary transformer help
 

Could someone tell me the proper way to hook up the transformers primaries for 120v?

http://www.apexjr.com/images/66938_sc7.pdf

The secondary is easy but I am not sure what color wires go to the hot, neutral and ground.

i would connect them in parallel for 120V, so connect 1 and 2, 3 and 4, the 1/2 combination to neutral, 3/4 to hot (but actually that does not make any difference, it's AC anyway). don't know what tha 1A and 4A are for.

1 and 4 are likely for 110/220V, 1A and 4A for 120/240V

That was what I was thinking but I needed some confirmation.

Any problem with connecting 1,1a and 2 and doing the same for 3,4a and 4?

connect 1 and 3 to mains, measure the secondary voltages, and do the same with 1a and 3. any difference? or measure the resistance between 1 and 3 and 1a and 3.

I would say u should not buy this/use this transformer as the schematic is very vague/wrong.

Hi,

I'd say 1A and 4A are for a 240V arrangement, 3 and 2 joined.

rgds, sreten.

Avel Lindberg is a very reputable manufacturer. I agree that the diagram could be better though. Measuring dc resistance from 1 to 2 and 1A to 2 will confirm which way has the most turns and therefore was intended for the higher voltage

1 and 2 are not connected.

Use 1 or 1A, 4 or 4A. Joining 1 and 1A together will cause a short and things will get very hot very quickly.

You can't parallel all three connections for both windings because for some reason they have put the extra part on the opposite ends of the two windings. So for 110V join 1 and 2, and 3 and 4, then use 1/2 for one connection and 3/4 for the other. For 120V join 1A and 2, and 3 and 4A, so the two connections then are 1A/2 and 3/4A. How do I know this? Look for the dots at the end of the winding diagram.