Food waste grinder from US

Thread Starter

R!f@@

Joined Apr 2, 2009
9,682
Knowing very well that it is a 120V one, my friend bought it. o_O
And it is upto me to run it. :rolleyes:

It's rated at 120VAC 9.1A, 60Hz.

I told him to get a 220V to 120V TX rated no less than 1200VA.

One problem, our mains is at 50Hz :confused:

So what will happen ?
 

#12

Joined Nov 30, 2010
18,167
The garbage disposers that I know about use a 4 diode rectifier to run a brushed DC motor. Frequency is a small problem in that case.
 

MaxHeadRoom

Joined Jul 18, 2013
19,449
There are also quite a few that operate with induction motors, if so it will run a little slower, check to see if it shows rpm, if it is an odd number such as 1740rpm then the odds are it is a 4 pole induction.
Max.
 

Thread Starter

R!f@@

Joined Apr 2, 2009
9,682
There are also quite a few that operate with induction motors, if so it will run a little slower, check to see if it shows rpm, if it is an odd number such as 1740rpm then the odds are it is a 4 pole induction.
Max.
My concern is running a 60Hz one at 50Hz.
 

MaxHeadRoom

Joined Jul 18, 2013
19,449
At this point, what do you have to lose, as already mentioned, if induction Motor it will run that much slower on 50hz.
If it runs ok it may pay to run it with a lighter load.
That seems like quite a hefty motor.
Max.
 

#12

Joined Nov 30, 2010
18,167
Look under its butt to see if that rectifier is in there. It's a square about 20 mm per side. If it's a DC motor, DC has no frequency that matters.

9.1 amps of 120 VAC is almost 1100 watts. That's enough for a whole horsepower. Way more than you need. This is not going to be a problem.
 
Last edited:

Glenn Holland

Joined Dec 26, 2014
686
The garbage disposers that I know about use a 4 diode rectifier to run a brushed DC motor. Frequency is a small problem in that case.
In my teenage years of the 1960s/70s, I was a handyman for the apartment building where my parents lived and very familiar with garbage disposers. Most were cheapy brands that had induction motors, but General Electric's "Disposall" had a DC series motor that was very hard to stall.
 

BR-549

Joined Sep 22, 2013
4,938
IF it is an induction motor.....you can safely and reliably run the motor......IF you drop the voltage. You will need a tapped auto transformer.

It will run at about 80% of 60Hz speed. Most times this turns out un-satistfactory. It's usually cheaper to purchase 50Hz motor.
 

GopherT

Joined Nov 23, 2012
8,012
The "motors" of a garbage disposal/grinder are not a standard appliance motor if it is a modern unit.

More of a stator coil and a driven shaft containing a magnet. The motor is not so easily replaced.



IMG_0070.PNG
 

MaxHeadRoom

Joined Jul 18, 2013
19,449
Most are 1ph induction motors, some will auto reverse each time they are activated, also, they occasionally jam, and there is a temporary release, which can be a Allen key arrangement etc.
A make identifier would help.
Max.
 

Thread Starter

R!f@@

Joined Apr 2, 2009
9,682
I will give it a try.
Now to find a 1400VA TX.

I assumed VA at 0.8 pf @ 120V, 9.1A

Am I correct here ?
 

Thread Starter

R!f@@

Joined Apr 2, 2009
9,682
1.2Kva min, a 1.5Kva would be the best choice.
Max.
Ya.....I recommended 1500VA and he said he is getting a 2000W one from Srilanka.

The transformer will probably cost more than a new garbage disposal.

Bob
You know what !
A 220V one cost the same as a 120V one with a TX. :D
He is scratching his head now. He wish he got the 220V from UK. Bought the 120V one to escape from customs.
 
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