Timer for a submersible deep well pump

[Kwolford]

I am not sure that device will work with a VFD? It says it will work with any motor starter, and a VFD does not have a motor starter. No, you do not need a soft start. That is just a sales gimmick, like the VFD.

Most VFD's have low current protection built in. I don't know about the WEG. But it should have an undercurrent adjustment. If so, you just need to figure out how to program it. But studies show you will spend 3 times as much maintaining a VFD pump system over 15 years, and an even higher percentage as more time goes by. As was said, and inexpensive 1/2HP single phase pump with a Cycle Sensor is the way to go. Just a matter of how much you want to spend maintaining the VFD before you switch.

From talking to the Pump contractor that set this system up for the previous owners, he said that the owner wanted to save money on the system (I guess by a cheaper 3 phase pump and the cost of larger gauge wiring?) The Weg does shut down when detecting dry pump/low current. The process to program the VFD to reset at intervals seems so complex that I’d rather do away with it, especially since I’d like to be able to easily change those parameters. It seems that the cheapest route right now would be the 3 phase pump monitor that I listed above and a combination of 3 phase converter and starting motor controller? What would be my actions for 3 phase conversion and motor starter? I’m gonna get a static level up there with a pump guy this Thursday and want all my options on the table before I go with a new single phase pump set deeper.

 

[Kwolford]

Seems unusual to me to have a variable speed system for filling a cistern. It seems weird to me to have a 2 hp pump 165 ft down for feeding a cistern for a home. I would be thinking 10 gpm 1/2 hp. For filling a cistern you don't need to develop much pressure at the surface. At first I was thinking 1/2 hp 5 or 7 gpm, but I looked at some pump curves.

A 5 gpm 1/4 hp multistage centrifugal pump might be better if they actually sold them.

Or maybe instead of a pump set at 165 ft in a 1000 ft well (can that be right?), you should consider a single phase pump set much deeper. You would need a pump selected to match your situation... set the pump at 500 ft, for example.... That pump might be a 5 gpm pump with a 6 or 7 gpm Dole valve to prevent upthrust when the water is high.

You might not even need a cistern with the well bore supplying storage. What diameter is that well?

Paperwork from previous owner shows 1170’ of 8” well casing and 980 ft. Of 5” pvc liner. Pump paperwork shows 2hp 4” Berkeley submersible installed 105’ deep with #8-3 submersible wire. Help me understand what they did wrong and various options to control the existing pump vs. putting a single phase deeper down? I appreciate all the help for a guy that’s just learning about all this and trying to make sense.

 

[Sponsor]

 

[Reach4]

Help me understand what they did wrong and various options to control the existing pump vs. putting a single phase deeper down?

For this to be right, the pump seller would have to think this is a ..... no, I am not going to try to think of a scenario where this makes good sense for the buyer.

My thoughts that either there is an error in the description, or this was totally inappropriate to the job. Like maybe the pump is at 765 ft rather than 165. And even then, a variable speed pump to fill a cistern seems like a bad idea to me. (I softened unconscionable to "like a bad idea".) I am not a pro.

With an 8-inch well having 2.8 gal per Foot of Depth storage in the well, you can see how that could be useful.

 

[Kwolford]

For this to be right, the pump seller would have to think this is a ..... no, I am not going to try to think of a scenario where this makes good sense for the buyer.

My thoughts that either there is an error in the description, or this was totally inappropriate to the job. Like maybe the pump is at 765 ft rather than 165. And even then, a variable speed pump to fill a cistern seems like a bad idea to me. (I softened unconscionable to "like a bad idea".) I am not a pro.

With an 8-inch well having 2.8 gal per Foot of Depth storage in the well, you can see how that could be useful.

Dug deeper into old paperwork and found the original pump set at 300’. I was looking at paperwork from 6 years after that that showed that they set the pump down 105’ which was additional depth. So, it is set at 400’ now. I think the VFD is the problem. It’s getting an error that I assumed was because it is running dry, but the error code is showing improper peak currents.

 

[Fitter30]

From talking to the Pump contractor that set this system up for the previous owners, he said that the owner wanted to save money on the system (I guess by a cheaper 3 phase pump and the cost of larger gauge wiring?) The Weg does shut down when detecting dry pump/low current. The process to program the VFD to reset at intervals seems so complex that I’d rather do away with it, especially since I’d like to be able to easily change those parameters. It seems that the cheapest route right now would be the 3 phase pump monitor that I listed above and a combination of 3 phase converter and starting motor controller? What would be my actions for 3 phase conversion and motor starter? I’m gonna get a static level up there with a pump guy this Thursday and want all my options on the table before I go with a new single phase pump set deeper.

Three phase from a vfd isn 't the same as three phase from a power company. Check with the pump monitor company first ,don't think it will be compatible with a vfd. When using a vfd to covert single to three phase the drive has to be at minimum twice the hp. Whats the model of weg vfd.

 

[Kwolford]

Weg CFW-08. I am getting an error code that I assumed was the pump running dry, but now that I’m starting to understand more of how this whole system works, it may be that the Weg might be running the pump in the wrong direction and giving me very little flow and then erring out to the following:


Improper electric thermal level

 

[Reach4]

Dug deeper into old paperwork and found the original pump set at 300’. I was looking at paperwork from 6 years after that that showed that they set the pump down 105’ which was additional depth. So, it is set at 400’ now.

Big difference.

Weg CFW-08. I am getting an error code that I assumed was the pump running dry, but now that I’m starting to understand more of how this whole system works, it may be that the Weg might be running the pump in the wrong direction and giving me very little flow and then erring out to the following:


Improper electric thermal level

Got a manual? I don't see that at https://www.weg.net/institutional/U...w08-users-manual-0899.5242-manual-english.pdf

It may mean the motor is running hot. It may mean the controller is running hot. A flow inducer on the pump would make the motor run cooler.

Interesting idea that the pump could be running backwards. I think the test would be to swap two phase wires and see if flow increases or decreases.

Have you tried talking to the company?

 

[Fitter30]

Change rotation change any two leads on the load side ( going to the motor) turn incoming power off wait 5 minutes before changing leads ( capacitor have to discharge).

 

[Valveman]

It won't hurt to switch two motor wires and try running it in the opposite direction, It will either be better or worse instantly and you will know. But unless someone messed with it they don't usually change rotation direction on there own. Makes more sense that it is installed 400'. They could show enough difference in wire price to make a 3 phase and VFD seem practical. However, the longer the wire from a VFD the higher the voltage to the motor, which can damage the motor. "Ringing" or a reflective wave is created by a VFD that increases the voltage as the wire to the pump gets longer. High voltage to the motor can cause damage that would make the readout say "Improper electric thermal level".

From that deep you will need a 5 GPM, 3/4HP or a 7 GPM, 1HP.

 

[Kwolford]

Change rotation change any two leads on the load side ( going to the motor) turn incoming power off wait 5 minutes before changing leads ( capacitor have to discharge).

The Weg drive can actually change rotation by programming. Just discovered that is the problem. Pump has been running backwards and not getting enough water to cool and throwing off error code for thermal shutdown.

 

[Valveman]

Yeah you can change rotation in the drive. Just one more thing that can go wrong with a VFD. Maybe you can get it worked out this time. But eventually you will get tired of the problems and expense of the VFD. And as was said a regular pump monitor will not work with a VFD as many times the monitors can't even see the type of power created by a VFD and can't get a reading.

 

[Fitter30]

The Weg drive can actually change rotation by programming. Just discovered that is the problem. Pump has been running backwards and not getting enough water to cool and throwing off error code for thermal shutdown.

If you change the rotation by program I've see if default is cw and changed to ccw if drive is replaced or serviced it will run backwards unless the programmer leaves a cheat sheet ( if the vfd ends up in the weeds).

 

[Kwolford]

Yeah you can change rotation in the drive. Just one more thing that can go wrong with a VFD. Maybe you can get it worked out this time. But eventually you will get tired of the problems and expense of the VFD. And as was said a regular pump monitor will not work with a VFD as many times the monitors can't even see the type of power created by a VFD and can't get a reading.

Agree that they are a pain in the ass. Some snake oil salesman convinced the people who built this place to make it all way more complicated than it needs to be. But, until the pump is fried or the VFD is history, I’m gonna keep it.

 

[Kwolford]

It won't hurt to switch two motor wires and try running it in the opposite direction, It will either be better or worse instantly and you will know. But unless someone messed with it they don't usually change rotation direction on there own. Makes more sense that it is installed 400'. They could show enough difference in wire price to make a 3 phase and VFD seem practical. However, the longer the wire from a VFD the higher the voltage to the motor, which can damage the motor. "Ringing" or a reflective wave is created by a VFD that increases the voltage as the wire to the pump gets longer. High voltage to the motor can cause damage that would make the readout say "Improper electric thermal level".

From that deep you will need a 5 GPM, 3/4HP or a 7 GPM, 1HP.

It’s actually a 2HP Berkeley 3 Phase 230v 60hz rated at 6.7-8.1 Amp draw.

 

[Reach4]

It’s actually a 2HP Berkeley 3 Phase 230v 60hz rated at 6.7-8.1 Amp draw.

You forgot gpm...

 

[Kwolford]

It won't hurt to switch two motor wires and try running it in the opposite direction, It will either be better or worse instantly and you will know. But unless someone messed with it they don't usually change rotation direction on there own. Makes more sense that it is installed 400'. They could show enough difference in wire price to make a 3 phase and VFD seem practical. However, the longer the wire from a VFD the higher the voltage to the motor, which can damage the motor. "Ringing" or a reflective wave is created by a VFD that increases the voltage as the wire to the pump gets longer. High voltage to the motor can cause damage that would make the readout say "Improper electric thermal level".

From that deep you will need a 5 GPM, 3/4HP or a 7 GPM, 1HP.

If I decide to trash the VFD and replace with a single phase pump, will the existing #8 wire be robust enough to handle the amperage?

 

[Kwolford]

Big difference.

Got a manual? I don't see that at https://www.weg.net/institutional/U...w08-users-manual-0899.5242-manual-english.pdf

It may mean the motor is running hot. It may mean the controller is running hot. A flow inducer on the pump would make the motor run cooler.

Interesting idea that the pump could be running backwards. I think the test would be to swap two phase wires and see if flow increases or decreases.

Have you tried talking to the company?

Here’s the manual for the Weg: https://www.manualslib.com/manual/884811/Weg-Cfw08-Vector-Inverter.html?page=112#manual

After recharging for 4 days, was able to get the cistern to fill 1/3 (1500 gallon cistern) before Weg shut down with error. while it was filling, weg showed around 7.5 amps. Now, when restarting, it is 8.5 to 9 amps and shuts down after several minutes with the E05 error.

 

[Kwolford]

Here’s the manual for the Weg: https://www.manualslib.com/manual/884811/Weg-Cfw08-Vector-Inverter.html?page=112#manual

After recharging for 4 days, was able to get the cistern to fill 1/3 (1500 gallon cistern) before Weg shut down with error. while it was filling, weg showed around 7.5 amps. Now, when restarting, it is 8.5 to 9 amps and shuts down after several minutes with the E05 error.

Big difference.

Got a manual? I don't see that at https://www.weg.net/institutional/U...w08-users-manual-0899.5242-manual-english.pdf

It may mean the motor is running hot. It may mean the controller is running hot. A flow inducer on the pump would make the motor run cooler.

Interesting idea that the pump could be running backwards. I think the test would be to swap two phase wires and see if flow increases or decreases.

Have you tried talking to the company?

Here is the fault I am getting. Ran for several hours last night filling cistern 1/3 and this morning errs out after a minute or so with E05. Should I call an electrician or a pump guy?

 

[Reach4]

If I decide to trash the VFD and replace with a single phase pump, will the existing #8 wire be robust enough to handle the amperage?

Pump 400 ft down. New pump probably to be 5 gpm pump if its only job is to fill the cistern. #8 is still big enough to power a 2 hp single phase motor through 620 ft of power cable, so your #8 is more than enough for whatever you do.

Since the pressure required at the surface is about 0 psi, it looks to me as if a 5 gpm 3/4 hp pump would be up to the job. This is not a case where bigger is better. 5 gpm fills 1500 gallons in 5 hours. Your static water level is unknown. If the static water level is high, then a Dole valve to limit flow to avoid upthrust could be needed. That is a fairly cheap gadget that limits flow. You might have a 7 gpm Dole valve for a 5 gpm pump.

With a 3/4 hp motor, figure to use a 20 amp circuit breaker, tho my 3/4 hp pump is on a 15 amp breaker and has never tripped.

So in the single phase pumps, you will choose "3-wire" or "2-wire". 3-wire takes less starting current, so it can be driven by a smaller generator if it comes to that. A 3-wire "CSR" control box is more power efficient..

 

[Kwolford]

Pump 400 ft down. New pump probably to be 5 gpm pump if its only job is to fill the cistern. #8 is still big enough to power a 2 hp single phase motor through 620 ft of power cable, so your #8 is more than enough for whatever you do.

Since the pressure required at the surface is about 0 psi, it looks to me as if a 5 gpm 3/4 hp pump would be up to the job. This is not a case where bigger is better. 5 gpm fills 1500 gallons in 5 hours. Your static water level is unknown. If the static water level is high, then a Dole valve to limit flow to avoid upthrust could be needed. That is a fairly cheap gadget that limits flow. You might have a 7 gpm Dole valve for a 5 gpm pump.

With a 3/4 hp motor, figure to use a 20 amp circuit breaker, tho my 3/4 hp pump is on a 15 amp breaker and has never tripped.

So in the single phase pumps, you will choose "3-wire" or "2-wire". 3-wire takes less starting current, so it can be driven by a smaller generator if it comes to that. A 3-wire "CSR" control box is more power efficient..

Thank you for this. Dumb question for an intermediate fix to get rid of VFD. Can a 3 phase pump work on single phase power? Or an alternative to converting single phase to 3 phase other than a VFD? Karen at CycleStop was kind enough to pass on a link to a 3 phase version of a product like theirs:
https://www.nassarelectronics.com/en/product/pump-monitor-trifasico/

I suppose that would mean that I had to have a single phase to three phase conversion going into this pump monitor? What would be a simple solution to that? My email is: kenny@kennywolford.com if that is easier? You have been so helpful in educating me on how this system works and I’d like to have enough info. To keep my costs down when I contact pump/well contractors in my area.