I have a 2.2kw 400 Volt pump 200 m away from my house at the river. I want to change my eskom supply from 3 Phase to single Phase. Will one of these Units work ?

220V/380V 1.5KW/2.2KW VARIABLE FREQUENCY DRIVE VFD INVERTER

3 hours ago, MartinCoetzee said:

I have a 2.2kw 400 Volt pump 200 m away from my house at the river. I want to change my eskom supply from 3 Phase to single Phase. Will one of these Units work ?

220V/380V 1.5KW/2.2KW VARIABLE FREQUENCY DRIVE VFD INVERTER

Show us pump graphs and then we can have a sensible talk. Pumps are not about horsepower. 

Why are you pumping from the river? 

Edited May 16, 20197 yr by Johandup

Or distance, total head is the what needs to be known.

As well as pipe diameter and material plse

Edited May 16, 20197 yr by Johandup
Spellcheckers is my kruis...

i live on a small holding and its my only source of water, the pipe is very old concrete pipes that are joined amd some pieces of 50mm class 6 pvc where it has been replaced. I only really fill a 5000 l water tank and fill water for the animals. it currently runs a 2.2kw pump. head is prop 5 to 6 m from pump to house and from pump to river about 3m. I want to go to single phase and use the same pump on a VSD 1 phase to 3 phase invertor.

 

You will have a benefit of less friction by replacing the concrete pipe with hope class 6. What is the price on an inverter? I’ve never heard of a 1-3 phase inverter. I am against complicated electronics. Variable speed won’t benefit you as the pump has to rotate at a certain speed to pump water.

With a 10m head over 200m pumping 5000l you can get by with an inexpensive small pump. Plenty for sale on the internet.

Jup, a new single phase pump and pipe will  be cheaper than the vsd probably.

8 hours ago, MartinCoetzee said:

my only source of water

Is it not an option for a ram pump too get the water up on the bank and then use a tank and gravity or a smaller pump to move it 200m?Just a thought.I am no expert at this.

1 hour ago, flamegrilled said:

use a tank and gravity 

Gravity means a bigger diameter pipe and is sloooww. 

Unless you can put up a 30m installation and pump to get to 3 bar.

Doesn't necessarily matter if it is only for drinking troughs and household use.

Martin most pumps like that can be converted from 3 phase to single phase with a capacitor.

Have a look at the nameplate on the pump .If you have problems post a photo.

41 minutes ago, Clint said:

Martin most pumps like that can be converted from 3 phase to single phase with a capacitor.

Mmmmh. I've certainly seen this done, but I don't think you can get full power from it. Considering first how a single phase motor works. It needs a slip angle to start the motor (assuming induction motor), so normally how you do it is you have a main winding and an auxiliary winding, and then you put a capacitor on the auxiliary winding to create a small phase shift (and hence a slip angle) so the motor can start properly. Otherwise it will just sit there humming until you spin it by hand.

Now you can do the same thing with a 3-phase motor, just pretend L2 is the auxiliary. It works, but you'll only have about a third of the power.  See here at 5:15.

Also see this one for a rotary converter. Here he uses L3 as an auxiliary windining to get it started, and then he uses the motor as an alternator that makes L2 an L3.

So I'm not saying do this... it's just for interest sake. If it's just one pump, just get a single-phase motor for it.

Yes you will always get a power loss converting from 3 phase to single phase .if you are running the pump below its max capacity (head height) then it might work.

I agree with plonkster I would rather try purchase a single phase pump than convert the old one.

There are lots available on the used market (Facebook) and other places.

It also bothers me a little that my explanation is a bit inaccurate. From what I can see you wire the motor in Delta, put live on L1, neutral on L2, and your capacitor-phase-shifted live on L3. Kinda sorta works but at reduced power.

Sell the 3 phase pump  buy a single phase pump. Easy.

Hopefully your 200m cable diameter will be adequate. 

And you’ll need a new switch.

Check it against tables.

cable is only 1.5mm over 200 m drawing around 3.4 amps per phase now. its only a 3 core so converting to single phase will be over 10 amps and voltage drop will be to much over that distance. This was like this when i bought the property.

10 hours ago, MartinCoetzee said:

cable is only 1.5mm over 200 m drawing around 3.4 amps per phase now. its only a 3 core so converting to single phase will be over 10 amps and voltage drop will be to much over that distance. This was like this when i bought the property.

Time to do the sums.

You can also try to buy 2nd hand cable of the right size. There is no need for perfect looking cables - it should be armored anyway.

Why do you want to move away from 3 phase? Unless there is a really compelling reason stay on it.

with eskom i am paying around 2500 availibilty before i use any electricity. if i go single phase this will drop allot. And its my first step towards going unto solar/pv.

Finances always makes sense.

There is a lot on powerforum of guys changing 3 phase db’s. Good reading.

With single phase you’re limited to a 7kW motor. It is huge. And the cable gets thicker.

I am a registered electrcian so that part i can do, my main question was really if any one is running 3 phase pumps of VSD drives.

1 hour ago, MartinCoetzee said:

I am a registered electrcian so that part i can do, my main question was really if any one is running 3 phase pumps of VSD drives.

@anotherbrownbear would be the man to talk to aboud VSDs.

On 2019/05/21 at 7:48 AM, MartinCoetzee said:

I am a registered electrcian so that part i can do, my main question was really if any one is running 3 phase pumps of VSD drives.

Do you have a name plate of the motor?

i will go take a picture tomorrow .