277V to 120V step down transformer

It will do that but:

- You have to take into account that it also increases the amps flowing through the primary winding of your transformer. However, given that the difference in voltage is around 5%, it would have little consequence.

- The waste heat produced by losses will be higher too. Be careful if your transformer is already working full nominal power.

Thanks for awesome response. now I feel confident my solution will work.

But what do you mean by wasted heat produced by losses will be higher too?

I'm using LED downlight and will only be 1/2 to maximum load capacity of the stepdown transformer.

The electrical efficiency of a transformer is usually around 95%.

The remaining is waste heat losses..

Your project should work.

Again, thank you very much for your great information and giving me so much confidence.