Anyone have recent experience with VFD well pumps?

[Xfaxman]

Dumb smart phones .

 

[GSVette]

What size tank are you using?

Does the pump run after a toilet is flushed?

I put the 10 gallon tank in when I plumbed in the csv- I haven’t really noticed if the pump kicks in or not/ it is a low flow toilet so it might not trip the bypass

 

[Valveman]

Good discussion guys! 2HP and smaller pumps only need 1 GPM to stay cool. So the CSV1A and the CSV125-1 have 1 GPM minimums, fill the tank at 1 GPM, and keep the pressure constant and the pump running continuously when using more than 1 GPM. The small tanks (4.5 or 10 gallon size) only hold 1.2 and 2.4 gallons of water respectively. So yes the pup will come on when you flush a 1.6 gallon flusher. But the CSV keeps the pump from cycling on/off for showers, and everything else you use water for. So it doesn't hurt to add back a cycle for every toilet flush, as the total cycles will still be much less. Although it really doesn't add a cycle for every toilet flush, just every water use event. So when you flush and wash your hands, step into the shower, or someone elsewhere in the house is using water at the same time, there is no extra cycle for a single flush.

3HP and larger pump need 3-5 GPM to stay cool. So the CSV125-3 has a 3 GPM minimum, fill the tank at 3 GPM, and keeps the pump running when using more than 3 GPM.

The CSV3B2T has a 5 GPM minimum, which is recommended to keep a 5HP or larger pump/motor cool. It will fill the tank at 5 GPM, and keep the pump running when using more than 5 GPM. When using less than 5 GPM, like with a 3 GPM shower, the CSV makes the pump act like a 5 GPM pump working with a pressure tank. We would recommend a minimum of a 44 gallon size tank with 10 gallons draw. When using a 3 GPM shower the tank will supply the water for 3 minutes, the pump comes on and 2 GPM goes into the tank as the other 3 GPM is being uses for the shower. 2 GPM will fill the tank in about 3 minutes. So the pump will be on for 3 minutes and off for 3 minutes, worst case. If you up size to an 86 gallon tank, we set it to still take 3 minutes to fill, but it will double the off time to 6-7 minutes. 3 minutes on and 7 minutes off is about right when using 3 GPM in the house.

I am glad the VFD's are getting less expensive and more reliable, as constant pressure is a wonderful thing. VFD's were not cheap and didn't last very long when I was using them 30+ years ago. But even so a VFD is going to be more expensive and less reliable than a simple mechanical valve, like the CSV. Just don't fall for the hype that VFD's save energy, because they do not. Then it is a no brainer which is the least expensive and most reliable way to get constant pressure from your pump system. The CSV was designed to mimic the constant pressure performance and replace troublesome and expensive VFD's.

 

[downslope]

....Then it is a no brainer which is the least expensive and most reliable way to get constant pressure from your pump system. The CSV was designed to mimic the constant pressure performance and replace troublesome and expensive VFD's.

Assuming you have a large enough diameter casing, would it be asking too much to have a system that could supply between 7 and 250 gpm at pressure range of 10 to 60 psi with cpv, vfd or some combination thereof?

 

[Valveman]

Actually a CSV can make a pump work safely at much lower flow rate than a VFD. So yes a CSV can make your pump deliver a constant 60 PSI while you are using between 5 GPM and 250 GPM. The CSV de-rates the motor load while a VFD creates a smaller motor from a larger one. The CSV causes the amps to drop so low the motor will stay cool at 5 GPM or less. A motor controlled by a VFD still needs the full 0.5 feet per second to cool the motor, which means a 6" motor in 7" casing needs a minimum of 25 GPM to stay cool.

Usually the CSV is set to deliver a single constant pressure like 60 PSI. On systems where you need lower pressure in some lines like for a drip system, we just use a pressure reducing valve on the line to the drip irrigation. The CSV will always deliver 60 PSI for the rest of the system, and the line going to the drip irrigation has a pressure reducing valve set at 15 PSI or so.

 

[downslope]

Actually a CSV can make a pump work safely at much lower flow rate than a VFD. So yes a CSV can make your pump deliver a constant 60 PSI while you are using between 5 GPM and 250 GPM. The CSV de-rates the motor load while a VFD creates a smaller motor from a larger one. The CSV causes the amps to drop so low the motor will stay cool at 5 GPM or less. A motor controlled by a VFD still needs the full 0.5 feet per second to cool the motor, which means a 6" motor in 7" casing needs a minimum of 25 GPM to stay cool.

Usually the CSV is set to deliver a single constant pressure like 60 PSI. On systems where you need lower pressure in some lines like for a drip system, we just use a pressure reducing valve on the line to the drip irrigation. The CSV will always deliver 60 PSI for the rest of the system, and the line going to the drip irrigation has a pressure reducing valve set at 15 PSI or so.

Yes, that is what I was considering; (1)drip system running alone, maybe 5-30 gpm @15psi. (2)Impact sprinklers alone, maybe 250-300 gpm @50-60 psi or, (3) some combination of both at certain times, if practical.

 

[Valveman]

Yes that will work just fine. You can run them one at a time or all at once. Even though the amps will drop considerably when using only a small amount of water and the pump is being controlled by the CSV, it will still be more efficient to work as close to the 300 GPM max the pump can do. So anytime you can run them all at the same time it will be more efficient. However, the CSV will make the pump run perfectly and last a long time even when you are just using 5 GPM like for a single garden hose or drip system.

 

[STx]

So I thought I'd update this thread in case my experience is helpful to anyone else. I ended up buying the 5HP Franklin Electric / Flint & Walling motor and their 55GPM pump head. I ran a new 8 gauge wire from the panel to the well and used new 8 gauge pump wire down the hole. For the first couple of months, it worked great, everything I had hoped. In late May or early June, I suddenly wasn't able to get more than 5 GPM at pressure, anything above that would drop pressure to 20 PSI or less. Long story short, I ended up.sending the pump back to the factory and they decided that sand in my well had damaged the impellers and it wasn't covered under warranty. Ok, I get it, I asked about repair costs and was told that they don't work on "used" equipment and that if we wanted the pump.and motor destroyed to just let them know. This is a $3,000 motor and pump with 3 months or less of use. Final solution was that they sent me back the pump and motor and I bought a new impeller cartridge for $530 that I had to install myself. To top it all off, the motor showed back up missing 2 of the lock washers and nuts. I will NEVER buy another F&W product and will definitely be sure to share my experience with a time that asks about them.

I put a $300 4HP/40GPM pump I bought on Amazon in while this was all getting worked out. When it fails (last one gave me 18 months), I'll put the newly rebuilt F&W back in and either buy another $300 pump to have as a backup for when that fails or I'll go to Goulds if their customer service is better.

I want to be clear that I am and was fully willing to pay for repairs by the factory. There is some sand in my well (I'm sure that's the case in most wells) and while I think a submersible pump should be built to handle that, they explicitly stated that abrasive damage voids the warranty, so their policy is clear and I can't really argue that. What I'm truly disappointed with is their complete lack of service after the sale. They had to open the pump to troubleshoot it, how much extra effort would it have required for them to simply put the new cartridge in instead of the old one?

So, I'm telling you guys to be aware that if you purchase a F&W and it fails for something that they seem unwarrantable, you're on your own. They won't work on it for any price, their solution will be to destroy it and sell you a new one, even if what you have is less than a year old.