24000 BTU AC Unit conversion to geothermal well water source - Page 7

ledbalon · 12-19-16, 04:20 PM

likely will need a step up transformer to get you to the correct voltage. the motor is a sealed style the motor / compressor is suspended on the bottom of the outer housing that may be what you hear going thunk

ledbalon · 12-19-16, 04:27 PM

just realized this likely a 3 phase compressor.. to run that you will need a way to produce 3 phase power. likely best way to do that is to use a motor to drive a three phase motor to produce 3 phase at the correct voltage. Would have to say likely there are easier ways.. sell it and get a compressor that is single phase sigh....

b420ady · 12-19-16, 05:36 PM

Yes, unfortunately is a 3 phase motor , I did some research and I could buy a 1 phase to 3 phase motor speed controller which is expensive or construct something like this:

Driving Three Phase Motor on Single Phase Supply - Circuit Diagram - Electronic Circuit Projects

BTW this website seems very interesting for people that are doing electronic projects !

What I could not find is how much power can that circuit provide and what else I need apart from that because it does not look to expensive or complicated at a first look but please correct me if I m wrong

ledbalon · 12-19-16, 07:30 PM

it is not easy.. one takes a single phase leg on the three phase motor .. this energizes the core of the motor.. then you have to spin it up to the required hz which on this compressor is 60 hz. you may still need to use a transformer to change the voltage to run the compressor.. meaning three transformers one for each leg

b420ady · 12-19-16, 09:14 PM

Quote:

Originally Posted by ledbalon

it is not easy.. one takes a single phase leg on the three phase motor .. this energizes the core of the motor.. then you have to spin it up to the required hz which on this compressor is 60 hz. you may still need to use a transformer to change the voltage to run the compressor.. meaning three transformers one for each leg

From what I ve read the circuit provides in this way 330 V , would this be enough ?

Another method is with the classic capacitor method used for 3 phase motors in shops:

How to use three phase motor in single phase power supply - Electrical Engineering Centre

https://www.youtube.com/watch?v=FSxaU162FRc

https://www.youtube.com/watch?v=3I1Y5odIP5g

Five Cases Where 3-Phase Motors May Run Single Phase - U.S. MOTORS

Can someone with better electronic knowledge step in please and say if we can do this capacitor method ?

I think the circuit in this video is the salme with this link:
Driving Three Phase Motor on Single Phase Supply - Circuit Diagram - Electronic Circuit Projects

https://www.youtube.com/watch?v=AkaUvVaplWg

ledbalon · 12-19-16, 09:52 PM

well good that you have a han on the compressor.. do make sure you tape off the pipes you said they were hissing

jeff5may · 12-19-16, 10:51 PM

Ledbalon,

I was joking! If you can heat AND cool with one unit at the same time, that could double-leverage your energy savings. Sounds like a great idea to me.

B420ady,

What you have is a 3 phase, 2 HP industrial compressor. Roughly equivalent to 2 tons (24000 btu) of cooling capacity. Seeing your posted ratings, this is a tougher compressor than normally found in residential equipment. If you can breathe life into it, the thing should be able to handle some pretty harsh service and survive.

The hard part of making this thing work will be supplying it 3 phase power. You will need some kind of drive circuit to run it if you don't have 3 phase power line access. I would definitely take it somewhere that does to test it out. Same basic deal as the mini-split unit before. Make sure it can pump gas before dreaming up a circuit and plumbing for it.

EDIT: oops, got home from work last night and wrote this post without refreshing my browser. My mistake.

The last circuit is probably the best (the digital drive). These are available for cheap as a packaged, programmable drive unit. Benefits include variable speed, better power factor, no startup surge, and increased motor life. Google search terms: vfd, inverter drive, variable frequency drive.

b420ady · 12-21-16, 09:13 AM

Can you give me some links because I did not find them cheap as you said.

Fionn · 12-21-16, 05:09 PM

Just one point about you gaining confidence from the fact that commercial GSHP units use flat plate heat exchangers.
What you're not appreciating fully is that they are all designed for closed loop input loops, not open loop systems like you plan to run.
Fouling is not a concern with closed loop systems.

b420ady · 12-21-16, 05:54 PM

I understood the same thing as you said, but after looking at the local companies I ve realized that almost all the geothermal heat pumps they are selling for open source use flat plate HX so I m thinking that I can take my chances with it at least for a season.

12-19-16, 10:51 PM	#67
jeff5may Supreme EcoRenovator Join Date: Jan 2010 Location: elizabethtown, ky, USA Posts: 2,428 Thanks: 431 Thanked 619 Times in 517 Posts	Ledbalon, I was joking! If you can heat AND cool with one unit at the same time, that could double-leverage your energy savings. Sounds like a great idea to me. B420ady, What you have is a 3 phase, 2 HP industrial compressor. Roughly equivalent to 2 tons (24000 btu) of cooling capacity. Seeing your posted ratings, this is a tougher compressor than normally found in residential equipment. If you can breathe life into it, the thing should be able to handle some pretty harsh service and survive. The hard part of making this thing work will be supplying it 3 phase power. You will need some kind of drive circuit to run it if you don't have 3 phase power line access. I would definitely take it somewhere that does to test it out. Same basic deal as the mini-split unit before. Make sure it can pump gas before dreaming up a circuit and plumbing for it. EDIT: oops, got home from work last night and wrote this post without refreshing my browser. My mistake. The last circuit is probably the best (the digital drive). These are available for cheap as a packaged, programmable drive unit. Benefits include variable speed, better power factor, no startup surge, and increased motor life. Google search terms: vfd, inverter drive, variable frequency drive. Last edited by jeff5may; 12-20-16 at 06:30 AM..

12-19-16, 04:20 PM	#61
ledbalon Lurking Renovator Join Date: Nov 2010 Location: dayton tn Posts: 17 Thanks: 0 Thanked 0 Times in 0 Posts	likely will need a step up transformer to get you to the correct voltage. the motor is a sealed style the motor / compressor is suspended on the bottom of the outer housing that may be what you hear going thunk

12-19-16, 04:27 PM	#62
ledbalon Lurking Renovator Join Date: Nov 2010 Location: dayton tn Posts: 17 Thanks: 0 Thanked 0 Times in 0 Posts	just realized this likely a 3 phase compressor.. to run that you will need a way to produce 3 phase power. likely best way to do that is to use a motor to drive a three phase motor to produce 3 phase at the correct voltage. Would have to say likely there are easier ways.. sell it and get a compressor that is single phase sigh....

12-19-16, 05:36 PM	#63
b420ady Helper EcoRenovator Join Date: Nov 2016 Location: Romania Posts: 47 Thanks: 19 Thanked 0 Times in 0 Posts	Yes, unfortunately is a 3 phase motor , I did some research and I could buy a 1 phase to 3 phase motor speed controller which is expensive or construct something like this: Driving Three Phase Motor on Single Phase Supply - Circuit Diagram - Electronic Circuit Projects BTW this website seems very interesting for people that are doing electronic projects ! What I could not find is how much power can that circuit provide and what else I need apart from that because it does not look to expensive or complicated at a first look but please correct me if I m wrong

12-19-16, 07:30 PM	#64
ledbalon Lurking Renovator Join Date: Nov 2010 Location: dayton tn Posts: 17 Thanks: 0 Thanked 0 Times in 0 Posts	it is not easy.. one takes a single phase leg on the three phase motor .. this energizes the core of the motor.. then you have to spin it up to the required hz which on this compressor is 60 hz. you may still need to use a transformer to change the voltage to run the compressor.. meaning three transformers one for each leg

12-19-16, 09:52 PM	#66
ledbalon Lurking Renovator Join Date: Nov 2010 Location: dayton tn Posts: 17 Thanks: 0 Thanked 0 Times in 0 Posts	well good that you have a han on the compressor.. do make sure you tape off the pipes you said they were hissing

12-21-16, 09:13 AM	#68
b420ady Helper EcoRenovator Join Date: Nov 2016 Location: Romania Posts: 47 Thanks: 19 Thanked 0 Times in 0 Posts	Can you give me some links because I did not find them cheap as you said.

12-21-16, 05:09 PM	#69
Fionn Lurking Renovator Join Date: Aug 2015 Location: Ireland Posts: 25 Thanks: 3 Thanked 6 Times in 2 Posts	Just one point about you gaining confidence from the fact that commercial GSHP units use flat plate heat exchangers. What you're not appreciating fully is that they are all designed for closed loop input loops, not open loop systems like you plan to run. Fouling is not a concern with closed loop systems.

12-21-16, 05:54 PM	#70
b420ady Helper EcoRenovator Join Date: Nov 2016 Location: Romania Posts: 47 Thanks: 19 Thanked 0 Times in 0 Posts	I understood the same thing as you said, but after looking at the local companies I ve realized that almost all the geothermal heat pumps they are selling for open source use flat plate HX so I m thinking that I can take my chances with it at least for a season.