Quote Originally Posted by slow-poke View Post
Craig,

For reliability we don't design to nominal voltages, we design to worst case, as stated the utility specified tolerance is 240V + 6% , resulting in 360Vdc, These drives have a 350V bulk capacitor. I completely agree 600V FET's are common as nails so are 400V capacitors. In all likelihood the Delta drivers have 600V FET's and 400V capacitors, IIRC the S.O. drives have a 350V capacitor! Furthermore the mains voltage in New Zealand is nominal 230V.
Just to be clear, the stepperonline T6 drives do have 400v caps. I can see two large caps with 400v 560uF marked on them. There are also some smaller CD28S caps I can see. My concern would be that there are other electronics in the drive that might not be able to handle higher then the 242v they are rated for.

So I guess my question from all of this is, besides cost, is there a reason NOT to use a transformer to bring voltage into the manufacturer recommended range? Seems like using a transformer cannot hurt.

I live in NA and have seen voltages at my house as high as 249VAC, typically in the afternoon its around 243VAC.