DIYbanter - View Single Post - Unbalanced Phase Converters and Power Loss

On 12 Dec 2004 07:17:02 -0800, wrote:

I use a 7.5HP rotary phase converter to run my 2HP Sheldon Lathe. I was
taking a medium cut in some 1020 steel in backgear and after a couple
of passes it seemed that the lathe was losing power. I opened the
cabinet up and the motor was very hot. If I disengaged the power feed
and retracted the tool the lathe would come back up to speed.

The motor is the original and it is wired properly at 220v.

Is it possible that the converter not being balanced or tuned is
causing this power loss. Bob Swinney sent me an article on balancing so
it will not be a problem to do so as I have ordered some run
capacitors.

I do not have the voltages right now on the 3 legs. Should I measure
these with the lathe running with no load?

Thanks, Steve

Actually..it sounds like you have lost one leg completly. Might check
the voltages at the motor and then see if the motor will run from any
other 3ph source. It could be you have lost a winding in the motor as
another cause.

Gunner

"To be civilized is to restrain the ability to commit mayhem.
To be incapable of committing mayhem is not the mark of the civilized,
merely the domesticated." - Trefor Thomas