Help Needed from Any Scala2 or VFD Experts

Users who are viewing this thread

Valveman

Cary Austin
Staff member
Messages
14,583
Reaction score
1,296
Points
113
Location
Lubbock, Texas
Website
cyclestopvalves.com
Cary,

I have been in the business for over 25 years, like the CSV, have installed 50+ CSV systems and they have issues of their own, especially in systems with high iron and manganese content - though mineral content is likely not an issue with the OP's situation considering he is on a municipal water supply. I know all about the affinity laws, I understand fully that CSV's don't cause the pump and motor to work harder, and I can still say that no one system is perfect for every scenario - even a CSV. As for the total energy use, I was the first person at the first VFD seminars we attended to ask the manufacturers of these VFD's to provide us dealers some written literature showing the real world cost savings a VFD could provide, to help us sell the product, and never once did a manufacturer do that. Once I realized the manufacturers wouldn't put the alleged "cost savings" in writing I made sure our company never used cost savings as a sales pitch - understanding of the affinity laws makes it nearly impossible to believe a VFD will save you money over a CSV installation, but for a typical residential family of four I don't believe the energy costs of the two systems vary enough to matter for most homeowners.

Installing 100's of VFD systems over the past 15 years or so I can say for certain they are now pretty reliable as long as you understand how to install them and set them up. They have not caused us to go out of business or pull my hair out and, if anything, the demand for them in the industry is growing because so many people who have them like them and then tell others about them. That's not to say a CSV system won't do almost the same thing as a VFD (CSV systems don't provide soft starts for motors which is very beneficial for commercial and industrial submersible pump applications and the high total head caused by CSV's just sometimes isn't acceptable due to existing underground piping), but in some applications a VFD makes sense. Also you can't disregard the appetite some people have for technology and they like the simple intuitive display the VFD systems offer. I'm not saying that would matter to you or I, but it does matter to some.

In the case of the OP and the SCALA2, the main attraction may have been the advertised all-in-one nature of the SCALA2 product. While installing a CSV on a standard shallow well jet pump may seem easy to you or I, in reality it's not something everyone would describe as simple. Knowing how/where to install the CSV in relation to the pump and tank, moving the pressure switch (and the wiring involved in properly doing so), and then adjusting the pressure switch would be daunting to many homeowners whereas installing a SCALA2 is simple.

I do believe the SCALA2 will work for the OP, its just a matter of figuring out what problems he's having and helping him through the process.

Thank you very much! I couldn't agree more. There are lots of good applications for VFD's. The CSV only works with pumps in a certain range of flow and pressure, and with fairly cool and fairly clean water. However, that is about 95% of all water well and booster pump applications. The VFD is good on really deep wells, positive displacement pumps, and when pumping sewage, oil, blood platelets, etc. And yes VFD's have gotten a lot more dependable and less expensive. I can't argue with someone wanting to try new technology, I did the same thing. But the simpler the pump and controls the more likely water will squirt out of the faucet. And when there are two or more ways to accomplish the same task, as with a VFD or CSV, the simplest way is always best.

I really love VFD;s and pumps like the Scala. It gets people use to constant pressure and small pressure tanks. Then when they decide they want their constant pressure water supply to be dependable, I will still be here. :)
 

HOOS1990

New Member
Messages
5
Reaction score
0
Points
1
Location
Virginia
To the prior poster that asked about my pressure, no the pump is not running as the pressure rises. The pump cuts off at the proper pressure, then the pressure slowly rises (maybe over 30 - 35 minutes) from 70 all the way to 120.

If anyone has any ideas of what to try (check tank pressure? install another tank?) it is much appreciated. It seems each thread here turns into a VFD vs. CSV debate. While I appreciate that a CSV might fix my problem, just trying to get the one I have to work and fully understand after reading many threads on this forum that a CSV could work if I cannot get this one working.
 

Valveman

Cary Austin
Staff member
Messages
14,583
Reaction score
1,296
Points
113
Location
Lubbock, Texas
Website
cyclestopvalves.com
The only way pressure can increase when the pump is off, is if the pressure reducing valve on the inlet leaks by and you have that much pressure on the inlet. All pressure relief valves will have creep or will leak until pressure on both sides equalizes. A little larger pressure tank might help. A pressure relief valve would keep the pressure from increasing, but will always be popping off if the extra pressure tank doesn't work.
 

Reach4

Well-Known Member
Messages
38,749
Reaction score
4,400
Points
113
Location
IL
If anyone has any ideas of what to try (check tank pressure? install another tank?) it is much appreciated.
Put in a thermal expansion tank for the water heater. If you have one, set the air precharge to 71. If you have done those things and still get the big pressure rise, get a bigger thermal expansion tank, because you have a big water heater, and you set the temperature hot.
 
Last edited:

Valveman

Cary Austin
Staff member
Messages
14,583
Reaction score
1,296
Points
113
Location
Lubbock, Texas
Website
cyclestopvalves.com
Put in a thermal expansion tank for the water heater. If you have one, set the air precharge to 71. If you have done those things and still get the big pressure rise, get a bigger thermal expansion tank, because you have a big water heater, and you set the temperature hot.

Yeah or thermal expansion because the built in tank in a Scala isn't large enough for anything.
 

shane21

Member
Messages
52
Reaction score
6
Points
8
Location
Ohio
The only way pressure can increase when the pump is off, is if the pressure reducing valve on the inlet leaks by and you have that much pressure on the inlet. All pressure relief valves will have creep or will leak until pressure on both sides equalizes. A little larger pressure tank might help. A pressure relief valve would keep the pressure from increasing, but will always be popping off if the extra pressure tank doesn't work.

This isn't quite accurate. A pressure reducing valve (PRV) should not leak, especially in the time frame referenced by the OP. If yours does, it probably needs replaced. I own a rental property with 185 PSI (yes 185 PSI is correct, that is not a typo) on the inlet municipal water line and use a PRV to get the pressure down to 65 PSI and it doesn't creep up over an hour, a day, or even a weekend when the water in the house is not used. I have a pressure relief valve on the system after my tankless hot water heater and it never leaks - I know because I check it 2-3 times a week after having a PRV fail a few years ago that was subjecting the house plumbing to 185 PSI occasionally that caused the first pressure relief valve to leak.
 
Last edited:

shane21

Member
Messages
52
Reaction score
6
Points
8
Location
Ohio
Put in a thermal expansion tank for the water heater. If you have one, set the air precharge to 71. If you have done those things and still get the big pressure rise, get a bigger thermal expansion tank, because you have a big water heater, and you set the temperature hot.

This guy almost certainly nailed it, assuming you do have a PRV, check valve or some type of backflow preventer on the incoming line from your municipal water system and a traditional hot water tank, a thermal expansion tank on the water heater is about the only fix possible. You could test this theory by turning off your hot water heater, running water through it until the water coming from the hot water tank is cool, and then watching the gauge after you shut off the faucet to make sure it doesn't creep up.

(I am assuming you have a check valve or backflow preventer and not a PRV because if you had a PRV you could just adjust it to allow more pressure into the house rather than install a booster pump)
 

Valveman

Cary Austin
Staff member
Messages
14,583
Reaction score
1,296
Points
113
Location
Lubbock, Texas
Website
cyclestopvalves.com
This isn't quite accurate. A pressure reducing valve (PRV) should not leak, especially in the time frame referenced by the OP. If yours does, it probably needs replaced. I own a rental property with 185 PSI (yes 185 PSI is correct, that is not a typo) on the inlet municipal water line and use a PRV to get the pressure down to 65 PSI and it doesn't creep up over an hour, a day, or even a weekend when the water in the house is not used. I have a pressure relief valve on the system after my tankless hot water heater and it never leaks - I know because I check it 2-3 times a week after having a PRV fail a few years ago that was subjecting the house plumbing to 185 PSI occasionally that caused the first pressure relief valve to leak.

All pressure reducing valves have creep. When it gets to creeping too much, it needs to be replaced. But an expansion tank and a pressure relief valve should always be plumbed after a pressure reducing valve, to handle the creep. Pipes can expand and absorb some of the creep so it is hard to see, but it is always there.
 

shane21

Member
Messages
52
Reaction score
6
Points
8
Location
Ohio
All pressure reducing valves have creep. When it gets to creeping too much, it needs to be replaced. But an expansion tank and a pressure relief valve should always be plumbed after a pressure reducing valve, to handle the creep. Pipes can expand and absorb some of the creep so it is hard to see, but it is always there.

I suppose if measured as a small enough unit they all have some creep but, colloquially speaking, the creep should be unnoticeable over at least a day and probably longer. If you are seeing a consistent creep of even a few PSI over a day it should be serviced or replaced. I know my system doesn't creep even 1 PSI in a weekend and I don't have a thermal expansion tank. I also have about 3 times as much pressure on the inlet side of my PRV as the outlet side.

Back to the OP's issue, I don't think he has a PRV so this is a rather a moot point in his thread.
 

Valveman

Cary Austin
Staff member
Messages
14,583
Reaction score
1,296
Points
113
Location
Lubbock, Texas
Website
cyclestopvalves.com
There are really only two kinds of valves, those that leak, and those that will leak. Pressure doesn't magically increase to 120 PSI by itself. That pump cannot even build 120 PSI if it was running. Creep would only cause the downstream pressure to increase to 120 PSI if the upstream pressure was higher than 120 PSI. Gotta be thermal expansion, which is why it happens over 30 minutes or so. Bigger tank, 75 PSI pressure reducing valve, and then all you have to do is worry about the pump when that time comes.
 

Tommy Cook

New Member
Messages
1
Reaction score
0
Points
1
Location
Massachusetts
My kid pushed the air valve on my scala 2 and emptied the factory precharged air pressure from the internal tank. What do I use to recharge the factory 18psi? Just a standard air commpressor? Thanks
 

Reach4

Well-Known Member
Messages
38,749
Reaction score
4,400
Points
113
Location
IL
Just a standard air commpressor?
Yes. Given the small volume, you might even get by with one of those lousy "250 psi" tire inflators. Those are not so good for car tires, but your pressure tank will be much smaller volume than a car tire. Even a manual tire pump should be fine.

If buying something, however, buy something rated in CFM or SCFM rather than psi.
 
Top
Hey, wait a minute.

This is awkward, but...

It looks like you're using an ad blocker. We get it, but (1) terrylove.com can't live without ads, and (2) ad blockers can cause issues with videos and comments. If you'd like to support the site, please allow ads.

If any particular ad is your REASON for blocking ads, please let us know. We might be able to do something about it. Thanks.
I've Disabled AdBlock    No Thanks