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 electric motor techs: Can I run a 220v single phase motor on a 110v house line? and add a Freq drive
gaspain  [Team Member]
8/24/2005 9:01:34 PM
heres the motor specs:

900 rpm
1.2 hp
220 VAC
Two speed(switch)
single phase motor

I want to be able to run it off a regular 110v house line. I will be replacing the two speed switch with a Frequency drive to.

Whatcha think?


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Pangea  [Team Member]
8/24/2005 9:04:52 PM
I'm no expert but I have run 220v items on 110v. They don't perform to potential but they will run.
krpind  [Team Member]
8/24/2005 9:10:17 PM
I have only seen freq. drives on 3ph motors.

I don't have any idea, I would bet, no.

Sorry, I am no help.

ETA, Can you rewire it to 110V, it is only a 1.2 hp motor, it might be dual voltage.
gaspain  [Team Member]
8/24/2005 9:21:12 PM

Originally Posted By krpind:
I have only seen freq. drives on 3ph motors.

I don't have any idea, I would bet, no.

Sorry, I am no help.

ETA, Can you rewire it to 110V, it is only a 1.2 hp motor, it might be dual voltage.



I dont know. I dont own it yet, and the people who sell it dont know either because its imported from Italy.

Basically it doesnt have to be a frequency drive, but it does have to be able to run off of 110v house line and have some sort of variable speed controller.

Im not very good with AC devices, this is a new territory for me

kells81  [Team Member]
8/24/2005 9:24:06 PM
Look at the motor, it should be tapable for either 110 or 220, It should have a diagram or something to identify this on a plate somewhere on it. it will say something like 120/208, then under amps should say something like hmm lets say 22/08. I would say that all you need to do is retap the leads in the motor.
Ky_Bob  [Team Member]
8/24/2005 9:27:59 PM
It will pull (roughly) double the current at 110 that it does at 220.

We have an old 220 compressor that is rewired for 110. It pulls hella current and runs hot as hell but still works, mainly because of light and intermittent use.

Bob
AC_Doctor  [Member]
8/24/2005 9:28:40 PM

It will pull (roughly) double the current at 110 that it does at 220.

This is actually correct, even though it seems not probable. The motor will pull an assload of current trying to start though, and will
cook the motor in a short amount of time if starting under any substantial load.




You will overheat the motor if you run it on 115v if it is a 220v motor. If it is dual-voltage, the tag should say 115v/208v or 115v/230v. If you run a 115v motor on 230v, the motor will run like a bat out of hell for a minute, then fry. Remember that the higher voltages will draw LESS amperage. Hope this helps.

AC_Doctor
Licensed Master Mechanic
purplecheese  [Team Member]
8/24/2005 9:28:45 PM
What brand is this?

Model #?

I looked on the website that was linked with the photo but don't see any specs on it.
GotGuns  [Team Member]
8/24/2005 9:29:29 PM
Couldn't you just wire up a step up transformer to the input? I don't know how big or pricey one would be, but it seems simple enough....
H46Driver  [Member]
8/24/2005 9:30:01 PM
How many amps? You could buy a transformer.
roguetrader  [Team Member]
8/24/2005 9:32:21 PM
you realy have to worry about the amperage at 110, the 220 will try to pull double the amps which may blow most breakers in your home.
ffsparky26  [Member]
8/24/2005 9:36:05 PM
What is the motor driving?

If the motor is not wound for 120/220 then you could try to order it sans motor and get a motor for it over here.

GotGuns  [Team Member]
8/24/2005 9:37:02 PM
Assuming the motor draws the same amount of power at 110 as it does at 220, then you are going to have twice the current running through the motor. Not a good thing. There is a reason that a 220V plug is physically different from a 110V plug, and it's not to get you to spend more money at Home Depot.

ETA: Sad, but I just graduated with an electrical engineering degree and I've already forgotten almost everything about AC motors......shoulda done more homework.
kells81  [Team Member]
8/24/2005 9:47:58 PM
It should pull a little more than double on 120, which if you retap the motor and replace the breaker it will not burn, we do conversions all the time when we have to install stuff like that, horse walkers, irragation pumps etc, sometimes we cannot find the exact same motor so have to improvise. lol if I had my UGLY's book and knew the effiecency of the motor could prolly tell you how big of a breaker and wire to use. it prolly pulls somewhere around 8-11 amps on 220 which would put it around 18 -21 amps on 110, a 20 amp brkr would hold for a minute but are only desinged to hold 16amps continuous. You can only load breakers up to 80%

My suggestion is to call a qualified person to do it. cheapest way is to add a 20amp, 250V Recepticle in the garage,
Britt-dog  [Member]
8/24/2005 9:58:27 PM
You must have 3ph power to properly vary the speed (sign wave) of an electric motor.
Check to see if a 3ph replacement motor is available.
If so a VFD will do phase conversion if properly derated,
IE 5hp drive running 3 hp motor or 10hp drive for 5hp motor
The higher hp drive will deal with the extra heat.

The drive will not change your voltage, it must be done with a boost transformer, prior to the drive.
krpind  [Team Member]
8/24/2005 10:04:16 PM

Originally Posted By kells81:
It should pull a little more than double on 120, which if you retap the motor and replace the breaker it will not burn, we do conversions all the time when we have to install stuff like that, horse walkers, irragation pumps etc, sometimes we cannot find the exact same motor so have to improvise. lol if I had my UGLY's book and knew the effiecency of the motor could prolly tell you how big of a breaker and wire to use. it prolly pulls somewhere around 8-11 amps on 220 which would put it around 18 -21 amps on 110, a 20 amp brkr would hold for a minute but are only desinged to hold 16amps continuous. You can only load breakers up to 80%

My suggestion is to call a qualified person to do it. cheapest way is to add a 20amp, 250V Recepticle in the garage,



A 1.2 hp motor should not pull more than 12 amps on 110. ( and that would be high)

That pic looks like a small pump, just go to Harbor Freight and buy a 110V pump that is probably cheaper than this one, AND sure as hell is cheaper than everything mentioned except rewiring it to 110V (if it is a dual voltage motor)
GotGuns  [Team Member]
8/24/2005 10:14:45 PM
1.2 horsepower = 900 watts

Now, assuming this motor is 100% efficient, that would mean that it draws 8.2 amps at 110 V and 4.1 amps at 220 V. Now, it probably is not 100% efficient, seeing as that is impossible an all, the 12 amps as stated before should be a good number to shoot for. A 15 amp service *should* cover it. You just have to worry about the current rating of the motor windings and the drive circuit, which will probably be designed after the 4.1 amps for the 220 V spec.

This is not considering the much higher current that the motor will pull during startup. I don't know how fast a breaker will trip if it's current ratings are exceeded. You may actually need to go with a bigger circuit, like 20 amps or maybe even 30 amps if it is a hog when it starts. I'm more of a DC motor guy myself though, so I could be wrong.....

Edited because I'm an idiot and was figuring 2hp instead of 1.2 for some reason....
krpind  [Team Member]
8/24/2005 10:20:08 PM

Originally Posted By GotGuns:
1.2 horsepower = 1500 watts

Now, assuming this motor is 100% efficient, that would mean that it draws 13.6 amps at 110 V and 6.8 amps at 220 V. Now, it probably is not 100% efficient, seeing as that is impossible an all. A 20 amp service *should* cover it. You just have to worry about the current rating of the motor windings and the drive circuit, which will probably be designed after the 6.8 amps for the 220 V spec.

This is not considering the much higher current that the motor will pull during startup. I'm more of a DC motor guy myself though, so I could be wrong.....



You are right.
most "quality" motors are rated at about 80%, that one looks like one of the cheap imports, so
I would expect even less efficiency.
I run 2 hp motors on pressure washers running a 3 + amp burner circuit on a 20 amp circuit with no problem. ( as long as an extention cord is not used)
gaspain  [Team Member]
8/24/2005 10:23:37 PM
Thanks ya'll!

I have some thinkin to do now. I suppose I'll just buy the damn thing and start throwing new parts at it till it works as its nearly impossible to find a food grade stainless steel flexible impeller wine pump that runs off 110v and is variable from 1 gallon a min to 30 gal min and has 1.5" tri-clove fittings and has a variable speed remote and is under 1,000 bucks.....sorry got to rambling
krpind  [Team Member]
8/24/2005 10:27:44 PM

Originally Posted By gaspain:
Thanks ya'll!

I have some thinkin to do now. I suppose I'll just buy the damn thing and start throwing new parts at it till it works as its nearly impossible to find a food grade stainless steel flexible impeller wine pump that runs off 110v and is variable from 1 gallon a min to 30 gal min and has 1.5" tri-clove fittings and has a variable speed remote and is under 1,000 bucks.....sorry got to rambling



What kind of pump do you need?
It looks like a brass head. Does it have a rubber impeller?

You can build what you need at Grainger.

Get a DC motor with a DC drive and vary the speed.
I MIGHT have the DC drive that would work, as we quit using them and went to a gear reduction motor.
GotGuns  [Team Member]
8/24/2005 10:28:22 PM
Just out of curiousity, how long would the current have to exceed the breaker's rating before the breaker would trip?
kells81  [Team Member]
8/24/2005 10:29:23 PM
5 mins to a few hours, if it trips, reset and trips etc you will prolly burn up the panel etc.
krpind  [Team Member]
8/24/2005 10:31:34 PM

Originally Posted By GotGuns:
Just out of curiousity, how long would the current have to exceed the breaker's rating before the breaker would trip?



If it is close a few seconds I would guess....I have never measured it.

It is usually immediate if it is shorted,
krpind  [Team Member]
8/24/2005 10:33:59 PM

Originally Posted By kells81:
5 mins to a few hours, if it trips, reset and trips etc you will prolly burn up the panel etc.



You may be talking about the thermal protector.

I would not think the circuit breaker would allow that kind of variance.
bmick325  [Member]
8/24/2005 10:35:02 PM
Wine pump?

Do tell.
diesel1  [Member]
8/24/2005 10:38:29 PM
Are you sure you only have 110 available? Most house current around here is 110/220 fed off of 2 110 lines to allow either 110 or 220V. Check your breaker/fuse box. If you have 2 hot legs going to the main, you have 220 available. Then it's just a matter of tapping in somehow. I'd suggest leaving the switch alone.
gaspain  [Team Member]
8/24/2005 10:48:41 PM

Originally Posted By krpind:
What kind of pump do you need?
It looks like a brass head. Does it have a rubber impeller?

You can build what you need at Grainger.

Get a DC motor with a DC drive and vary the speed.
I MIGHT have the DC drive that would work, as we quit using them and went to a gear reduction motor.



i need a flexible impeller pump. The impeller is usually made of neoprene or nitrile. The pump body must be made of food grade stainless (316? I think). Jabsco is the style of pump head...but Jbacso is expensive. Im starting a very very small winery, but not small enough to not use a pump and im tight on cash.

BTW, the wine equipment industry is highway robbery. If you want to make alot of cash- sell wine making equipment.

here's some links to some pumps im looking at, if you are curious/bored/or whatever:

www.napafermentation.com/pages/pumps/pumpsmain.html
www.stpats.com/pumps.htm
www.tcw-web.com/Catalog%20Pages/CatPg53-56/html/CatPg53-56.html

BTW, thanks guys for the help. Its cool to talk AC motors and pumps, it gets the old noggin working





Merlin  [Team Member]
8/25/2005 7:16:31 AM
According to my handy-dandy Pocket Ref, a 1 1/2 hp motor at 115 VAC should take about 19.6 amps running current. This means it will likely need to be on a 30 amp circuit, which will require a separate branch and outlet for the motor alone.

Hope this helps.

Merlin
jcncc  [Member]
8/25/2005 7:24:16 AM
You will fry the motor.
Merlin  [Team Member]
8/25/2005 12:21:57 PM

Originally Posted By jcncc:
You will fry the motor.



Not necessarily. I have a 1 1/2 HP swimming pool motor that is designed for both 115 or 220 VAC. When I had to replace it, I just wired it for 220.

Don't know if his motor can be wired both ways, being a European design, he may not have the option; but if it is and he wires and connects it correctly (big IF IMO), it should be OK.

Merlin
gaspain  [Team Member]
8/25/2005 10:50:35 PM
update kinda;

I found out that the building is wired for 220v. Now i just gotts figure out how to connect a variable speed control. maybe a freq drive or something

thanks all!
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