Wiring new Step up transformer

I bought a new transformer to go from 240VAC input to 480 VAC output, I do not understand the schematic on the side of the transformer.

http://www.metalworking.com/DropBox/deckeltransformer_1.JPG

It seems to be saying to to use the H1 and H4 as the 480 leads and tie H3 and H2 together or is it just saying to just use H3 and H4 as the 480 leads and not worry about H1 and H2?????

I have the same question on the other side as well with the 240 voltage.
Are there 4 seperate windings?

Could someone clarify this for me?
Thank you,
Steve

"Could someone clarify this for me?"

Standard 240/480:120/240 control transformer, labeled according to NEMA specs.

As I recall, part of your Deckel can be rewired to 250 volts, by changing the motor from Wye to Delta, but the remainder is 480 only.

So, to step up your 240 to 480, you would connect the line as follows: L1---X1-X2 and L2---X4-X3; and you would connect the 480 section of your Deckel as follows: L1---H1 and L2---H4, with a jumper from H2-H3.

Just out of curiousity, what will it be powering? The .5KVA rating is kind of small for most 480V devices and only single phase (this step down transformer is typically used for lighting or control, etc).

IIRC, the load to be supplied is another control transformer, one which is rated 0.15 KVA, but which has some unusual secondary voltages, and which would otherwise be expensive to duplicate.

This situation is not unlike the Monarch dc drive (tube type) where the filament transformers come in 200-300 volt and 400-500 volt models, each with six primary taps, and replacements cost in the thousands. The total load on the two transformers is about 0.33 KVA. A single 240:480 control transformer rated about 0.5 KVA can provide the 460 needed by the filament transformers, and also the needs of the "three wire" control scheme, which includes a 460 contactor coil.

Hey Peter,
I'm guessing you didn't get my email about the other transformer, I've been having email issues lately. Basically the first ($10.00) transformer worked great until I started to turn up the demand and then it let all the smoke out :-(
No loss at 10 bucks it weas also a good proof of concept before I spent more on another transformer plus you warned be about that so I wasn't surprised.

The 480 side I understand but I'm confused by the line side. I would have expected the line side to be wired just like the 480 side, can you explain why it's not?

jstolaruk - Peter is exactly right, the mill is a 4 hp Deckel FP3L and the transformer is powering the conmtrol transformer for accessories.

As usual thank you very much,
Steve

"The 480 side I understand but I'm confused by the line side. I would have expected the line side to be wired just like the 480 side, can you explain why it's not?"

The transformer is 120/240:240/480.

Four methods of wiring the transformer would be:

1) 120:240 (primary in parallel, secondary in parallel; twice as much current flowing in the primary as in the secondary),

2) 120:480 (primary in parallel, secondary in series; four times as much current flowing in the primary as in the secondary),

3) 240:240 (primary in series, secondary in parallel; the same current flowing in the primary as in the secondary), and

4) 240:480 (primary in series, secondary in series; twice as much current flowing in the primary as in the secondary).

Since transformers are reversible, unless otherwise stated, there are four additional combinations:

5) 240:120,

6) 480:120,

7) 240:240, and

8) 480:240.

Because of NEMA terminal designation rules, parallel connections are always odd terminals to odd terminals, even terminals to even terminals; series connections are always first terminal and last terminal, with the intermediate terminals connected together and isolated from the first and last.

(In some instances, terminals might be brought to the safety ground, in order to establish a "separately derived" system).

Umm,
So since I want 240:480 wouldn't I want both sides to be in series?
Meaning
L1---X1 and L2---X4, with a jumper from X2-X3
L1---H1 and L2---H4, with a jumper from H2-H3

The picture shows 4 coils. 2 per side.
Your connection diagram shows L1---X1-X2 and L2---X4-X3

It seems to me that this is connecting both sides of one coil to L1 and both sides of the other coil to L2.
How does the current flow in this case?
Sorry if this is a dense question?
Steve

"Sorry if this is a dense question?"

Not at all, but one which could be easily clarified if you'd give me a buzz, which you are free to do at your convenience.

The principle here is there will be two control transformers functionally in series ...

240-to-480, and 480-to-120/6

... with the remainder of the machine, principally the spindle motor, operated on 250 (after reconnecting this motor from 480 Wye to 250 Delta).

I don't know why Deckel fused the 480-to-120/6 control transformer at 10 amps, as the capacity of this transformer is only slightly more than 0.1 KVA.