Motor question

Tue Dec 06, 2011 9:29 am   

I'm too tired to reason this out; does anybody know: Can a motor
designed to run off 50 Hz successfully run off 60Hz? I dimly recall
that motors designed for one frequency will operate safely on the
other, but which way can you go? Assume I'm using the proper voltage
for the motor.

Tue Dec 06, 2011 12:48 pm   

On 2011-12-06, spamtrap1888 <spamtrap1888_at_gmail.com> wrote:

Most should work, but bear in mind that many of their parameters depend
on the frequency. What kind of a motor is it?

--
weland_at_sdf.org
SDF Public Access UNIX System - http://sdf.org
% grep me no patterns and I'll tell you no lines

Tue Dec 06, 2011 6:11 pm   

On Mon, 5 Dec 2011 23:29:24 -0800 (PST), spamtrap1888
<spamtrap1888_at_gmail.com> wrote:


Simplest explanation:

A small increase in frequency shouldn't be a problem other than the
possible speed increase..

Going the other way is more of a problem as the motor would not have
enough iron in it for the lower frequency.

Tue Dec 06, 2011 10:21 pm   

"spamtrap1888"


** Synchronous motors will normally be OK at either 50Hz or 60 Hz.

This includes AC fans, turntable motors and workshop motors on bench drills
etc.

Thing is, 50 Hz equates to 230 volts and 60 Hz equates to 120 volts.

The motors will run 20% faster at 60 Hz - and maybe a tad warmer.



.... Phil

Tue Dec 06, 2011 10:26 pm   

"Phil Allison"


** A 60Hz design motor will run slower and warmer at 50Hz.



.... Phil

Wed Dec 07, 2011 12:05 am   

"spamtrap1888" wrote in message
news:ca815fe4-00cf-4301-b1c4-b2e3a707e43d_at_p14g2000yqp.googlegroups.com...

I'm too tired to reason this out; does anybody know: Can a motor
designed to run off 50 Hz successfully run off 60Hz? I dimly recall
that motors designed for one frequency will operate safely on the
other, but which way can you go? Assume I'm using the proper voltage
for the motor.

If it is a synchronous type motor, it will safely run, although a tad
faster: 6/5 x the design speed. Not usually an issue, other than the
slightly faster speed.

Wed Dec 07, 2011 1:04 pm   

On 2011-12-06, Phil Allison <phil_a_at_tpg.com.au> wrote:

Why warmer?

--
weland_at_sdf.org
SDF Public Access UNIX System - http://sdf.org
% grep me no patterns and I'll tell you no lines

Wed Dec 07, 2011 5:20 pm   

Weland wrote:


Magnetic saturation of the iron in the rotor and stator. It's the
same as transformer saturation at a lower than design frequency, if you
don't reduce the input voltage.


--
You can't have a sense of humor, if you have no sense.

Wed Dec 07, 2011 6:47 pm   

Phil Allison <phil_a_at_tpg.com.au> wrote:

Fans and drills don't use synchronous motors. Old clocks/timers and
turtables/tapedeck might.

Wed Dec 07, 2011 8:23 pm   

"Cydrome Leader"


** OK - so they use " induction " motors, which spin at a speed
determined by the AC supply frequency but are not synchronised with it.



..... Phil

Thu Dec 08, 2011 2:04 am   

On Dec 7, 2:23 pm, "Phil Allison" <phi...@tpg.com.au> wrote:

Years ago when I worked on military aircraft electronics we would
sometimes connect the lab clock up to the 115V 400 HZ supply. Who says
time doesn't fly on a Friday afternoon....Lenny

Thu Dec 08, 2011 3:30 am   

On Dec 7, 4:04 pm, klem kedidelhopper <captainvideo462...@gmail.com>
wrote:


In my youth I often puzzled why HP test equipment was rated to work
off 400 Hz -- why did the Air Force use that?

Thu Dec 08, 2011 3:41 am   

On 12/7/2011 8:00 PM, spamtrap1888 wrote:

Because the power transformers, filter chokes and capacitors
were smaller and lighter. Both very important things when
designing aircraft equipment.

Jeff


--
"Everything from Crackers to Coffins"

Thu Dec 08, 2011 4:41 am   

spamtrap1888 wrote:


smaller and lighter.


Jamie

Thu Dec 08, 2011 7:32 am   

spamtrap1888 <spamtrap1888_at_gmail.com> wrote in news:65ea6884-eee0-468b-
999c-08b692b15b02_at_18g2000prn.googlegroups.com:


To save weight and power on airplanes.
And to have compatebility between ground- and airborne
equipment.