Phasing transformers

Post "A" is the common on the 1034.

I thought all the "U" terminals were the common?

If the "A" terminal is the ground on the 1034 transformer, How would I phase the transformers if I want to use the B and U terminals for a variable voltage on one transformer and the B and C terminals for a steady voltage on the other transformer?

That's a quirk with postwar Lionel transformers: "U" terminals are not always common.

An easy way to determine if terminals of different transformers are in phase or not: power up both transformers without any cross-connections. Connect a lamp across the terminals in question, from one transformer to another - if the lamp lights up, the terminals are NOT in phase. If the lamp doesn't light, the terminals ARE in phase. Or use an AC voltmeter to do the same test.

Here's a link with more info: http://www.jwtrains.com/Tech%20Tip_6.htm

I recommend a lamp or voltmeter test instead of spark test.

So I just tried phasing a 1034 with my ZW. I jumped the U terminal of the ZW with the A terminal of the 1034. I then touched a wire between the A terminal of the ZW and the U terminal of the 1034 and got small sparks. So I reversed the plug on the 1034 and tried again but this time got a lot bigger spark. Shouldnt there be NO spark at all if they are in phase?

You want to phase common posts only, not variable posts. The link identifies the common posts for different transformers. http://www.jwtrains.com/Tech%20Tip_6.htm

They don't show a 1034 transformer but it may be the same as the 1033 transformer which appears to be the same case but with a whistle control.

You first have to set both transformers to the same voltage - 12 volts for example.  Your first try was actually in phase.

Very relevant, clear description HERE.

If you give an example of where this would need to be done, I can help guide you.

On my layout I have three independant loops of track and about 25 lights. I have a buss wire running undedrneath for use as a common ground between everything, that is the reason for phasing transformers. Two loops are controlled by the A and D terminals of the ZW. I want to control the lighting with a 1034 transformer using either the B and C terminals for a fixed 14 volts or the B and U terminals with a variable voltage of 4-14 volts. I also want to use another 1034 transformer to control the third loop of track with the B and U terminals with 4-14 volts variable. If I am not using the A terminal which is the common on the 1034, will the transformers still be in phase? I tested both 1034s using the methods explaoined above using the A terminal to phase transformers but do not plan on using the A terminal. Is this possible?

Perfect!

For both of your applications, you can phase the 1034 "B" terminals with the ZW "U" terminals, as long as you are dedicating these 2 transformers for this purpose.  You will get the desired results.

The 1034 is an often overlooked transformer because of its similarity to the 1033.  The 1034, however, offers two higher variable train voltage ranges, 10-20, and 4-14, compared to the 1033's 5-16 and 0-11.  This is due to the absence of a compensating circuit for the whistle control.

Thanks Rob, that got everything going correctly.

 I agree with you about the 1034 being overlooked. I think it also has to do with it being 75 watts versus the 1033 having 90. Im not concerned with it not having a whistle controller as I am using it to run an American Flyer EP5 New Haven bankers set.

Excellent.