strange motor bog-down

[John Frankl]

Hello All,

I have a 1.5 HP Baldor from TruGrit, just like the ones on the Hardcore grinders. It is 220V and in the U.S. I could not bog this thing down.

I have relocated to Korea and it works okay here, but it is really weak and easy to bog down. In fact, I can stop it with medium-heavy pressure.

I have been given two possible reasons (though there may be more and I'd love to hear them from you guys!):

The 220V electricity is 50MhZ vs. 60 MhZ (though I don't remember which is which).

The line I ran from the breaker to the actual outlet is too small/thin. I ran Romex 12 and the distance is about 15 feet. Then there is another 6 feet of cord on the motor itself, which may be 14. Would running 10 up the power significantly?

Thanks for any and all advice.

John Frankl

[Ray Rogers]

I'm not much of an electrician but I have wired my own shop and I am reasonably sure the wire is not the problem. Electricity in the USA is 60 mhz. Motors can run pretty good with some variance in voltage but I think the mhz is much more important. Also, I doubt that your motor requires more than 15 amps but if the Korean power can't provide the necessary amperage then that would be a significant problem. Either way (mhz or amperage) fixing this will require some kind of conversion/converter or another motor. Some devices can be set to run on either 50 or 60 mhz (another indication of how important that feature is) so maybe Baldor can tell you if the motor can be set up to work on 50 mhz....

[ColdIron]

The diff. in frequencies (50/60 hz - not mhz) shouldent be the problem.
Running a 50 hz motor on a 60 hz net (or reverse), does only result in a gain (or loss) of speed, not 'power'.
Imo your powerlines are to long and/or thin:

Ive got a 3 phase/400 volt/3.6kw (eq. 4.8 hp) grinder.
Running this 'trough' an extra 20m 2.5sq.mm. ext.cord result in a drop of voltage down to ~ 370volt eq. ~ 20% less power!

BTW running a 50 hz motor on 60 hz may damage the motor if it isnt designed for 60 hz!

[Gene Chapman]

http://kropla.com/frequency.htm