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Posted: 1/20/2013 12:31:50 AM EDT
Have a 50 cycle sinewave inverter at 230 volts.

What are constraints on running 60 Hz motors?
Link Posted: 1/20/2013 4:19:19 AM EDT
its just less power/rpm, not that you will notice.


I lived in UK for 4 years and contacted all manfs to make sure, delta dewalt jet pc, etc, etc.

They run fine but you will a transformer to get from 230 to 110
Link Posted: 1/20/2013 5:02:30 AM EDT
[Last Edit: 1/20/2013 5:02:59 AM EDT by wshbrngr]
I have a funny feeling he is going to use it to run a 220v 60hz well pump.
Link Posted: 1/20/2013 5:54:49 AM EDT
[Last Edit: 1/20/2013 5:57:19 AM EDT by EXPY37]
Originally Posted By wshbrngr:
I have a funny feeling he is going to use it to run a 220v 60hz well pump.



Wish I had a well.


Air comp...

Link Posted: 1/20/2013 5:55:44 AM EDT
[Last Edit: 1/20/2013 5:56:14 AM EDT by EXPY37]
Originally Posted By TaylorWSO:
its just less power/rpm, not that you will notice.


I lived in UK for 4 years and contacted all manfs to make sure, delta dewalt jet pc, etc, etc.

They run fine but you will a transformer to get from 230 to 110



Great!


Link Posted: 1/20/2013 6:15:00 AM EDT
Originally Posted By EXPY37:
Originally Posted By wshbrngr:
I have a funny feeling he is going to use it to run a 220v 60hz well pump.



Wish I had a well.


Air comp...


Rats,
it was just a guess.

My well is deep and 220v, and I have thought about something similar.
Link Posted: 1/20/2013 7:13:41 AM EDT
Won't hurt a thing. Motor will just run a little slower RPM. We do this all the time with electronic frequency drives to control speeds on hi tech machines. We drive some as low as 30 hz and some as high as 85 hz. All the motors are standard 60 hz.
Link Posted: 1/20/2013 7:29:17 AM EDT
Originally Posted By EXPY37:
Have a 50 cycle sinewave inverter at 230 volts.

What are constraints on running 60 Hz motors?


The answer is that in general probably none. The motor will run slower and its top end HP will be substantially less (by a factor of 5/6), but it probably will run OK.

You may find some single phase motors that are capacitor start have some issues. You might have to change the starting capacitor. Some motors have run capacitors that might need changing as well. Most starting switches will probably have kicked out the starting cap by 50 Hz, but you may find your motor does not.

You may also find that the torque the motor puts out at zero speed is inadequate to start the load if the starting cap is not sized for 50 Hz.

Having said all that, chances are it will work OK in most applications, but don't be surprised if it doesn't.

Link Posted: 1/20/2013 8:54:12 AM EDT
Originally Posted By cheez:
Won't hurt a thing. Motor will just run a little slower RPM. We do this all the time with electronic frequency drives to control speeds on hi tech machines. We drive some as low as 30 hz and some as high as 85 hz. All the motors are standard 60 hz.


The motors MUST be freq drive rated to do this. Look it up.
It will work but it isn't designed to. Runs hotter draws more current (amps)
Link Posted: 1/20/2013 9:27:24 AM EDT
[Last Edit: 1/20/2013 9:28:41 AM EDT by ilbob]
Originally Posted By mrrick:
Originally Posted By cheez:
Won't hurt a thing. Motor will just run a little slower RPM. We do this all the time with electronic frequency drives to control speeds on hi tech machines. We drive some as low as 30 hz and some as high as 85 hz. All the motors are standard 60 hz.


The motors MUST be freq drive rated to do this. Look it up.
It will work but it isn't designed to. Runs hotter draws more current (amps)


Some of what you are saying is sort of true some of the time.

First off, freq rated motors are about the insulation characteristics of the windings of the motor. VFDs use pulses with voltages that can exceed the insulation rating of the motors. Mostly this is a problem with older motors though.

It can run hotter especially with fan cooled motors because the fan runs slower and pushes a lot less air.

As for drawing more current, that is also sort of true as the motor will try to develop whatever HP is needed to run the load at the lower speed. A lot depends on what the load actually is. You can't make a blanket statement about this kind of thing without knowing what it is actually doing. If you are running a fan or centrifugal pump, the fan or pump will just do less work. Maybe enough less work so it can't do the job it was intended to do.
Link Posted: 1/20/2013 11:06:57 AM EDT
[Last Edit: 1/20/2013 1:45:00 PM EDT by EXPY37]
Here's a motor story since we're on the subject.


Back in the 80's when I was wet behind the ears and didn't know shit about like I do now, I bought a new USA brand of CNC vertical mill. I added 3 more later of the same model, for commonality of parts, maintenance, operation, --as used ones came onto the market at good prices, mostly from auctions. There were lot's of great equipment acquistion opportunities, as our economic collapse was just beginning at the time, and few recognized it.

The mills used what would now be considered a crude...

[yet complex, you should have seen the 6 phasing drive boards light up and their TO-3 transistor tops blow holes in them with sillycone fire spurting out, after I replaced all the Motorola Darlington power transistors on them, about 18 transistors, looked like a Christmas tree and I wasn't a happy camper.

I remember staring at them after I threw the main power switch and if "WTF" has a real meaning, that was it.

The transistors needed to be matched and I didn't know that until I went to buy a new set, about $400. So's I made a high current matching test setup and matched up about 5 or so sets of 18 transistors each, for future use.

The matching worked good and when I installed the new set the machine's 3 phase drive ran great for at least 15 more years. ]

...continuing .......3 phase motor drive that had control inputs similar to modern compact drives. The little modern drives are easily retrofitted into these mills. I sold one recently [with the original drive] that I had hung onto, to a machine shop and they immediately put it into production. Really good machines that may have had 50,000 hours on them when we finished with them in the mid 2000's. Talk abt getting your money's worth!

These machines did rigid tapping which means the motor slows down and reverses as the Z axis moves the tap into the workpiece and back out in synchronization. Real slow speeds. We tapped literally must be millions of small holes.

Anyhow, they used a standard GE 5 HP 3 phase motor for the spindle drive and I had one motor crack a motor housing. The machine was no longer supported but parts were generally supported by aftermarket companies. I learned the motor needed to have some sort of 'quality' to work well with the motor drive but I forget what it was. Something about the massiveness of the casting, wimpy 5 HP motors weren'r suppose to work well.

I remember connecting a modest quality 4 HP motor to the drive and it made noise. The GE motors were plain old high quality ones, nothing designed for variable speed and they worked real well.

After seeing how much a used replacement motor cost, I took the broken motor apart and figgered a way to make a temporary repair. The repair was two steel bands that clamped the cracked housing.

This expedient repair...

...the same sort of a repair that would be made in a SHTF when a replacement might not be available at any cost...

...worked from about 1988 to well into the 2000's when the machine was given to another company and ran there.

The motor ran perfectly and milled and tapped for maybe 20,000 more hours.








Link Posted: 1/20/2013 3:00:29 PM EDT
Originally Posted By EXPY37:
Have a 50 cycle sinewave inverter at 230 volts.

What are constraints on running 60 Hz motors?


Running a 60Hz motor at 50Hz will usually work. It's much better than trying to do the reverse, i.e. running a 60Hz motor at 50Hz where you can get issues with magnetic saturation causing excessive current consumption which can destroy the motor.

That said, it depends on the type of motor. A synchronous induction motor for instance will run, but will run at faster than the intended speed. Applications where motor speed is critical would not be happy.



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