Running 60 Hz motors on 50 Hz
Binni Thorsson
and will be moving my power tools with me. Iceland uses 220 V on
50 Hz. I have an assortment of tools, small and large(r). I can wire
my larger tools to run on 220 V and plan on using a voltage
transformer for my 110 V tools. However, the motors on most if
not all my tools are rated for 60Hz only. Can anyone tell me either
from experience or theory if I am going to ruin the motors or if
they are just going to run a little slower. I looked in the FAQ and
couldn´t find anything there.
Thanks in advance.
-Binni
Charles D. (Chuck) Jonah
situation. Obviously the universal-motor tools won't care (router, drill
or any other tool with brushes). The induction motors will run 5/6ths the
speed. Some should run happily on both frequencies, some will not.
I am not certain of this part but ... I suspect that one should be able to
modify the capacitor on some motors to make them run acceptably (the run
capacitor). At one time Bodine had a nice book on motors that I referred
to (it was in the library). I would try it and just check motor
temperature - the only hazard that I can see is overheating (but that may
be simple-minded).
Chuck
In article <3luphu$e...@hacgate2.hac.com>, Binni Thorsson
Chris Lewis
Binni Thorsson <bt...@vsys0.hac.com> wrote:
>I will soon move from the US to Europe (to Iceland to be specific)
>and will be moving my power tools with me. Iceland uses 220 V on
>50 Hz. I have an assortment of tools, small and large(r). I can wire
>my larger tools to run on 220 V and plan on using a voltage
>transformer for my 110 V tools. However, the motors on most if
>not all my tools are rated for 60Hz only. Can anyone tell me either
>from experience or theory if I am going to ruin the motors or if
>they are just going to run a little slower. I looked in the FAQ and
>couldn´t find anything there.
The universal motors (hand drills and the like) won't care - as long
as you get the voltage right. They can also run on DC, so anything
between 0-60Hz will be okay. (Much above their rated frequency,
secondary inductive effects may kick in and make them not work very
well).
The induction motors (usually table saws and other motors that run at 1800
or 3600 RPM) will still run, though at only 5/6th the speed. How long
they'll last is anyone's guess. They _will_ draw more current. On DC,
an induction motor will not move. Just smoke and melt. Whether at 50Hz
you'll see a problem, I dunno. I wouldn't risk it with large motors.
Universal motors have brushes. Induction motors do not. This should
allow you to distinguish the too.
--
Chris Lewis: _Una confibula non sat est_
Phone: Canada 613 832-0541
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Tom Unger
Universal motors (the kind with brushes, usually high speed and noisy):
No problem. Within limits, these motors are not too fussy - they can even
run on DC.
Induction motors:
These are the motors used in stationary power tools (generally). This
question is a little harder since it will depend on how much design margin
the manufacturer has designed into their motors. Offhand I would say it is
probably OK. The motor will definitely run slower (approx 20% slower).
You can verify that the motor does not run hotter on the 50Hz than it did
on 60Hz (with no load, ie. with the machine free-running). If you are
comfortable with such things you could measure the current which the motor
draws (again, at no load) on the 50Hz and 60Hz supply. If the voltages are
the same then you can compare the currents. If the motor is happy then the
50Hz current draw should not be more than the 10 or 20% greater than the
60Hz no load current draw. An approach which will definately please the
motor (if, in fact you could please a motor but this is not a metaphysical
forum) would be to apply a voltage which is 5/6's of the rated 60Hz
voltage. For example, if your motor is rated for 240VAC 60Hz, then it will
definately be fine with 200VAC 50Hz. You might be able to do some stunts
with off-the-shelf transformers and 3 phase voltage (if available).
Hope this helps
Tom Unger
Electrical Engineer
Guy Burnham
>I will soon move from the US to Europe (to Iceland to be specific)
>and will be moving my power tools with me. Iceland uses 220 V on
>50 Hz. I have an assortment of tools, small and large(r). I can wire
>my larger tools to run on 220 V and plan on using a voltage
>transformer for my 110 V tools. However, the motors on most if
>not all my tools are rated for 60Hz only. Can anyone tell me either
>from experience or theory if I am going to ruin the motors or if
>they are just going to run a little slower. I looked in the FAQ and
>couldn´t find anything there.
>Thanks in advance.
>-Binni
As noted, universal motors won't care. Induction motors may be a
different story. They will run but you should be aware of some
potential problems and be prepared to compensate for them.
1) They will run at 5/6 speed which will reduce your power and tool speed
proportionately. If belt driven, a pulley change could get the tool
speed back to normal if that is important.
2) If the motor is fan-cooled, which they almost always are, the fan
will run slower, reducing the current that can be tolerated to about
5/6 the nameplate rating. This with the speed reduction reduces
sustained HP to about 70% of rated. Still, if the tool is
intermitently loaded, it may cool off enough between loads to be OK.
Adding an external fan and keeping vents clean, etc. would also help.
3) If the motor is capacitor run type, the capacitor value is selected to
match the speed. This would introduce some further inefficiency (heat).
You might find a better capacitor value (I think it would be ~20% bigger)
fairly cheaply. The motor manufacturer could tell you.
4) Sometimes, cabinets are tuned and pulley ratios selected to minimize
vibration and noise. Changing to 50 Hz can upset this tuning. It
is usually better on belt drive equipment to avoid speeds that are a
multiple of line frequency for this reason. It's a little harder to
do this at 50 Hz because these nodes are closer together.
I hope this helps you make your choices. Good luck in your new home.
--
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Guy Burnham, Advanced Laserjet Operations, Hewlett Packard Co. Inc.
g...@boi.hp.com 208(396-3355)
I WORK TO LIVE ... I LIVE FOR TRAINS, and OLD TRUCKS, and OLD TRACTORS and ..
Disclaimer: Don't you be the only one to take me seriously!
--|--|--|--|--|--|--|--|--|--|--|--|--|--|--|--|--|--|--|--|--|--|--|--|--
"robert_h._galloway_(sgrd-udr-o)"
motor ran warmer under load than it ever did on 60 hz. Now back in the states
it runs cool again, confirming it was the current and not a problem with the
motor. The 1hp on the mill ran as cool as it ever did. Ergo, you'll just have
to keep an eye on the individual motor and see how it works. Also, my wife's
dishwasher ran well and never smelled as if overheated although I never checked
the motor to see if it was overly warm.
rhg
will soon move from the US to Europe (to Iceland to be specific)
>and will be moving my power tools with me. Iceland uses 220 V on
>50 Hz. I have an assortment of tools, small and large(r). I can wire
>my larger tools to run on 220 V and plan on using a voltage
>transformer for my 110 V tools. However, the motors on most if
>not all my tools are rated for 60Hz only. Can anyone tell me either
>from experience or theory if I am going to ruin the motors or if
>they are just going to run a little slower. I looked in the FAQ and
>couldn4t find anything there.
>
>Thanks in advance.
>
>-Binni
Bruno Bienenfeld
design for higher power desipation it will heat up and can be hazard
to work with.
Please chack with mfg. B4 you do any modifications.
from the log of AA6AD
Bruno Bienenfeld
Rhett Jones
>
> I will soon move from the US to Europe (to Iceland to be specific)
> and will be moving my power tools with me. Iceland uses 220 V on
> 50 Hz. I have an assortment of tools, small and large(r). I can wire
> my larger tools to run on 220 V and plan on using a voltage
> transformer for my 110 V tools. However, the motors on most if
> not all my tools are rated for 60Hz only. Can anyone tell me either
> from experience or theory if I am going to ruin the motors or if
> they are just going to run a little slower. I looked in the FAQ and
>
> Thanks in advance.
>
> -Binni
******
The motor will run slower, use less current, and generate slightly less
power.
No damage will result from lower frequency.
-Rhett
Allen Windhorn
>I will soon move from the US to Europe (to Iceland to be specific)
>and will be moving my power tools with me. Iceland uses 220 V on
>50 Hz. I have an assortment of tools, small and large(r). I can wire
>my larger tools to run on 220 V and plan on using a voltage
>transformer for my 110 V tools. However, the motors on most if
>not all my tools are rated for 60Hz only. Can anyone tell me either
>from experience or theory if I am going to ruin the motors or if
>they are just going to run a little slower. I looked in the FAQ and
Things that have "universal" motors, like drills and most sanders, will
probably run just fine on 50 Hz. These are the ones with brushes, that
you can see sparking inside when they run. If they are variable speed,
all bets are off.
Things with induction motors probably will not run OK on 50 Hz, unless
you reduce the voltage by 17%, and then you will only get 5/6 the horse-
power they are rated at.
Allen
------------
Allen Windhorn
Kato Engineering
"robert_h._galloway_(sgrd-udr-o)"
I'm not sure you're 100% correct. Something about the counter EMF
opposing the applied EMF and limiting the current flow. At 5/6 speed, seems
like the counter EMF may be less, also what about the inductive reactance,
seems like it might be lower at lower frquency. Maybe it was just the reduced
air flow with lower fan speed but I definitely had heating problems with my
lathe motor when run under heavy load for long periods. (No big problem, just
tripped the Klixon and I had to wait for it to cool off then remember not to
run for quite so long a time.)
rhg
>Binni Thorsson <bt...@vsys0.hac.com> wrote:
>>
>> I will soon move from the US to Europe (to Iceland to be specific)
>> and will be moving my power tools with me. Iceland uses 220 V on
>> 50 Hz. I have an assortment of tools, small and large(r). I can wire
>> my larger tools to run on 220 V and plan on using a voltage
>> transformer for my 110 V tools. However, the motors on most if
>> not all my tools are rated for 60Hz only. Can anyone tell me either
>> from experience or theory if I am going to ruin the motors or if
>> they are just going to run a little slower. I looked in the FAQ and
>> couldn4t find anything there.
>>