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Kimjon

Who knows their shit on electric motors?

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20200502_145616.thumb.jpg.ce0e5a49fe9d232a142ace0526e402ea.jpg

This is a 3 phase motor, obviously...as that's what the tag says.

My very basic knowledgeable of electric stuff is an equation I recall from school:

P = V.I

Now what's preventing me from losing this motor and substituting it for an equivalent 2.2kw power single phase alternative?

If 

P = V.I

2.2kw = 240v x I

I = 2.2x1000w ÷ 240v

I = 9.17Amps

 

Seams like not ridiculous amount of amps to draw?

Is this possible? As simple as finding a 2.2kw single phase motor and adapting it to fit my application?

Or is there a cheaper alternative to all the above?

Ideas, thoughts, experiences please...????

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Your standard outlet is rated at 10A, but you do want to make sure the wiring and connections are still up to the task to run it continuously or things may become flammable. You'll also have startup surge to worry about too, which without a soft start feature could probably pop fuses, depending on how things are wired.
You can also get single to 3 phase converters and stick with the same motor, but the current requirements remain the same when running it from a single phase source.

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Just now, Yowzer said:

You can also get single to 3 phase converters and stick with the same motor, but the current requirements remain the same when running it from a single phase source.

I'm interested in this. I've seen something on trademe along these lines, but I'm an electrical retard. 

I have a 3 phase cable running to my shed, but the sparky just took two of the phases and ran a circuit each way off a phase each. So I don't have 3 phase power, just 2 single phases, and a dead wire. Is it very expensive to get these phases wired up to an outlet for proper 3 phase?

 

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Just now, Kimjon said:

I'm interested in this. I've seen something on trademe along these lines, but I'm an electrical retard. 

I have a 3 phase cable running to my shed, but the sparky just took two of the phases and ran a circuit each way off a phase each. So I don't have 3 phase power, just 2 single phases, and a dead wire. Is it very expensive to get these phases wired up to an outlet for proper 3 phase?

 

Depends on whether you have three phases wired to your house. Not very common in residential areas, more common in rural.

My lift (4-post) has a 2.2 kw single phase motor for the hydraulic pump. Works fine.

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If you don’t need 3ph for anything else buy a 1ph motor

Pretty sure 3ph = more meters= more meter bills even if your not using it 

2.2kw is pretty much biggest 1ph domestic motor, what you would have on say a 15cfm compressor, they draw more on start up than anything else I’m aware of, if your shed handles and compressor then it’ll run a lift fine

Just check what switches the motor currently has and if they will handle the higher (single) current

also does the motor drive the lift (ie you need to swap phase for up or down) this is tricker with 1ph but doable 

 

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We have a 9" grinder that is 2.8kw single phase, soft start tho 

 

Edit*. Ling/

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Yes I've done exactly this about 12 months ago.

It's less painful to sell your hoist and get a new hydraulic one.

 

However if you really want to make it work, you'll need a 3kw cap start cap run motor and to replace your contactors with atleast 16A versions.

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Can you take a photo of the wiring inside the terminal box of the motor? 

It says 400v star, (Y) so it should be able to do 230v delta with a Chinese vsd or 2nd hand trademe one.

If you can get one cheap it will be the easiest way 

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Keep in mind it's easy enough for us to wire is VSD, but there's a fair bit of fucking about with limit switches etc.

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Thanks for the replies. I'm pretty quick to point out that I'm out of my depth knowledge wise here? As in clueless.

Our house has 3 phases coming into the meter box (we live rural). Apparently 1 phase runs directly to our water heater. The other 2 phases split around the house circuits.

The electrician put a 3 phase cable from the meter box to our shed, and connected 2 of the house phases up, but not the water heater one. Well that's my recollection of what happened?

I am keen on the idea of 3 phase power, even if it's just one outlet that I run an extension cable to, as and when required. But thought if I could just adapt a 2.2kw single phase motor off a water pump or something then that could be a cheap win?

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Just now, Kimjon said:

 

I am keen on the idea of 3 phase power, even if it's just one outlet that I run an extension cable to, as and when required. But thought if I could just adapt a 2.2kw single phase motor off a water pump or something then that could be a cheap win?

Yeah, maybe? Most water pumps won't be that grunty in the motor department and will have a different mechanical connection.

I'd be getting the 3 phase power sorted as you are 80% of the way there. I have it in my shed, just one outlet (lathe is direct wired) and I plug other the other things (high speed drill press, nibbler, hacksaw) as necessary.

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Just now, Nominal said:

Yeah, maybe? Most water pumps won't be that grunty in the motor department and will have a different mechanical connection.

I'd be getting the 3 phase power sorted as you are 80% of the way there. I have it in my shed, just one outlet (lathe is direct wired) and I plug other the other things (high speed drill press, nibbler, hacksaw) as necessary.

Yeah, makes sense. Good to think out loud sometimes and see what comes back. Thanks

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Just now, Kimjon said:

Thanks for the replies. I'm pretty quick to point out that I'm out of my depth knowledge wise here? As in clueless.

Our house has 3 phases coming into the meter box (we live rural). Apparently 1 phase runs directly to our water heater. The other 2 phases split around the house circuits.

The electrician put a 3 phase cable from the meter box to our shed, and connected 2 of the house phases up, but not the water heater one. Well that's my recollection of what happened?

I am keen on the idea of 3 phase power, even if it's just one outlet that I run an extension cable to, as and when required. But thought if I could just adapt a 2.2kw single phase motor off a water pump or something then that could be a cheap win?

 

Oh bro if you've got three phase then that is by far the best solution to get a circuit run to the hoist.

 

Conversion to single is about $800 for parts, depending on hookups.

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Sorry if I come across as negative, but it was generally a pretty miserable experience doing the conversation to end up with such a shit product that only just works.

 

 

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Just now, UTERUS said:

 

Oh bro if you've got three phase then that is by far the best solution to get a circuit run to the hoist.

 

Conversion to single is about $800 for parts, depending on hookups.

 

Just now, UTERUS said:

Sorry if I come across as negative, but it was generally a pretty miserable experience doing the conversation to end up with such a shit product that only just works.

 

 

That's all good, I'd rather hear it how it is. Thanks

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Just now, UTERUS said:

Sorry if I come across as negative, but it was generally a pretty miserable experience doing the conversation to end up with such a shit product that only just works.

 

 

Life.

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Not that it will prob worry you but I'd say the frame, shaft size will be different on a single phase motor vs 3 phase.

3 phase power would be good, so much 3 phase gear out there that's normally a heaps better price that single phase.

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I couple of motor details for ya. Looks like frame size is same and shaft size to.

Single phase is 13amps full load.

 

20200502_192737.jpg

Screenshot_20200502-192701_Chrome.jpg

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