Transformers in control panels for an AC unit 1

[DASKAT]

Ok Guys, I am looking for opions here. In my plant we have a panel with 2 transformers. a 3KVA just for control power and a 2 KVA just for the AC. Before my time an AC unit was replaced with a wrong model, a 230VAC unit. Being good little electrician and wanting to get the system back up, they grabbed the hot leg off each xfmer to provide the 230 VAC and life was good until the AC took a dirt nap as this is AZ and were lucky if we get 5 yrs out of an AC. The correct AC unit was the installed until it crapped the bed and again, low and behold the wrong AC was ordered, 230VAC. I know using the 2 hots from two different xfmers is just not right due to imbalances on the xfmers but I was wondering what would be the ramification of applying 480VAC to the 240VAC (low voltage) taps. I'm sure that it would produce the 240VAC needed but am I potentially damaging the primary or secondary by pulling such a stunt. One of my EE buds says it sounds good and sound, just looking for other opions.

 

[wayne440]

The technically correct options are to obtain an AC unit of the proper voltage, or use a 480/240v transformer.

I am not going to be the one that puts 480v into a 240V transformer winding just to try and run an AC unit.

 

[ScottyUK]

Applying 480V to a 240V winding will cause the iron core of the transformer to saturate. As a result of core saturation the winding will draw a very large current and whatever protection you have will operate almost immediately. You may damage something in the process, or possibly hurt yourself. Don't do it.

Wayne has given two perfectly acceptable solutions.

 

[DASKAT]

Thanks guys, both answers make all the sence in the world.