can a 440 volt primary transformer 220 volt secondary be used in reverse to provide 220 input and 440 output?

Question

i have a machine that requires 440 3 phase power, i have 220 all over the place. can a 440 primary 220 secondary be used in reverse to step up from 220 to 440? 75 kva transformers are easy to come by, but i dont know if they can be used this way.

Answer 1

If your 220 is 3 phase then 3 transformers connected in Delta on both the primary and secondary sides would provide 440V 3 phase. Verify that 75 KVA is large enough for your machine.

If you have not already, I would compare the cost of converting the machine to 220V.

Answer 2

Welll yes and no.. The voltage ratio reversal is OK but one must remember that when going from 220 to 440 the amperage is cut in half in availability and when going from 440 to 220 the amperage is doubled in availability.
Now here comes the NO part...you specified three phase..make sure that's what your input and output are and a 220 is generally wired star with a center tapped ground or delta with a corner ground. Look at the x-former before wiring it up it should have a schematic showing the connection details. Also in transformer reverse hookup with existing equipment make sure the secondary (440 side is large enough to do the work) . Like i said before you will get a loss in ampacity from 220 to 440 ..here's is how to calculate it..P(watts) = I(amps) x E(volts) x 1.732(sq rt of 3)
just substitute in 220 and 440 in for the same wattage you stated (75,000) and solve for I...or you can look it up there are lots of transformer handbooks which explain ratios and transformer wiring out there..One of my favorites which you must purchase is called the "Ugly's" book of electrical facts. Sounds odd , has lots of good stuff in it for electricians...From the E....

Answer 3

Technically yes , but it would be better to just buy a 220-3 phase motor, used 3-Phase motors are pretty cheap, 2-3 HP should run about $20 add $10 for each 1HP. Double check your 440 motor, most of them are dual wired for 440/220 operation.

You failed to mention if your 220 was three phase or not.

If you cant replace the motor then the safest bet would be a rotary converter.

Answer 4

The simple answer is yes.
If it's a 3 phase transformer, then you will need a three phase supply.
I'm not sure what effect a single phase split three ways will have on the system. It might cause over heating. Putting it simply, you need a three phase supply to have a 3 phase output.
Remember, when the voltage goes up the current goes down, and visa a versa.
I1 / I2 = V1 / V2
I1 - Primary Current.
I2 - Secondary Current.
V1 - Primary Voltage.
V2 - Secondary Voltage.

Answer 5

220 Volt Transformer

Answer 6

Is your 220v single phase? If so, you will need a phase converter. To answer your question, yes transformers can be back-fed

Answer 7

yes,
transformer can be use in any order,
taking one as primary and other as secondary.......
But,if transformer is one phase transformer,it can be used for one phase,not as a three phase.
You can also use three one phase transformer,one for each phase.......

Answer 8

yes of course

but you stand a good chance of frying yourself
especially with 3-phase

Answer 9

no
you can buy inverters that will do that but a transforer can not preform like that