[GreenKeys] 14-15-19 Etc. motor

[Ralph Mowery]

After taking a close look at things, I see the light.

The motor in question is a 50 hz motor,but it only runs at 1500 rpm so when
running at 60 hz it will run at 1800 rpm.  

This motor is rated for 110 volts, so should work ok in the US if the
correct gears are used.

Not having a 50 hz motor in hand, I just wonder if 
Teletype put enough iron in the motors so they would run at 50 or 60 hz and
just slapped on the name tag whatever they needed for the countries power
grid and made gears to make up the difference ?

Iron and air flow does make a difference.  With enough air flow for cooling
it may be possible to run the 60 hz motor at 50 hz. 

-----Original Message-----
From: Jim Haynes [mailto:jhhaynes at earthlink.net] 
Sent: Thursday, July 05, 2018 3:47 PM
To: Ralph Mowery
Cc: GreenKeys at mailman.qth.net
Subject: Re: [GreenKeys] 14-15-19 Etc. motor

It's really quite simple.  The 50 Hz motor will turn at 1800 rpm when
powered by 60 Hz.  The only difference in the motors is the extra iron
needed to work at 50 Hz.  1800 RPM is the same speed the 60 Hz motor runs.
Teletype gear sets are not permanent parts of the motor, so a gear set
for any 60 Hz speed will work equally on a 50 Hz motor running on 60 Hz
power.

If you ran a 60 Hz motor on 50 Hz power the speed would be 1500 rpm and
the motor would overheat from lack of iron causing excessive currents
in the winding.

Of course this is all about synchronous motors.  Speed governed motors
are a different matter altogether.

Now there's also the matter of line voltage, since 115V more or less is
the standard in the U.S. but 230V is the standard in Europe where 50 Hz
power is commonly used.  I neglected to mention that in the earlier 
posting.  If it's a 230V motor you can run it in the U.S. by hooking 
across the two "hot" leads of the power system rather than one hot and
one neutral as is standard for all 115V appliances.  Or you could use a
step-up transformer.  The line voltage should be printed on the motor
nameplate.