Pressure Switch

[dalehileman]

The Forum participant frustrated over the maintenance of his plunge may be interested in the following exchange to which I was privy owing to a lapse in Internet software security

But to summarize without requiring a busy Forum participant to read the entire exchange below can you help me out here: (1) Is my plan the usual way of handling the difficulty and (2) if it is, what would the unit be called besides just "pressure switch" and (3) could you recommend one, preferable carried by amazon.com.

On Feb 9, 2010, at 8:33 AM, Elad wrote:

As my Polaris booster pump is damaged if run dry for only a moment, entailing a massive repair bill, I'm wondering if you know of a pressure switch with a load capability of about 13 amps that would turn it on after the psi at the output of the main pump has reached, say, 15 to 20 psi. If you know who might carry such a device could you please send me some info about it—Thank you kindly—Elad

On Feb 10, 2010, at 5:27 AM, Sien Glensker [Elad’s fellow pool owner] replied:

Is it possible that the pump is running dry when the pool sweep accidentally moves up a wall surface high enough to get part of the head out of the water and thereby taking in air, which is causing your problem?

Hi Sien:

No, the Polaris operates under pressure from that auxiliary booster while intake to the main pump is derived from the skimmer port. However, when water level has fallen to near the bottom of this port some air is drawn in along with the water though it's hard to imagine the mixture could so damage the booster

But after a period of system disuse (during extended maintenance for instance) the tubing leading from skimmer to main pump partially empties owing to the latter—incredibly--being situated at a higher level so that when the system is re-energized it is unable to draw water, blowing the system full of air

I believe it can also be caused by failure to adequately tighten the cover of its input pump-basket vessel; air leakage here owing to a worn or damaged O-ring; a problem in some intermediate system such as an in-line chlorinator; if during maintenance you should happen to somehow energize the booster before the main pump…...

Under these circumstances the only way to restore the system to operation is to prime it with a big bucketful of water poured into the vessel, then quickly closing the vessel, remembering of course the O-ring. While doing so remember also to hold down the right side of your mouth with your left index finger while farting to the tune of Auld Lang Syne

Thus it's possible I had inadvertently left the booster on during one such episode causing it also to run dry with the consequent disaster

I'll never get over in this day and age of aerospace exploration and miraculous new invention how primitive are our pool systems wherein the tiniest flaw causes disastrous, irreversible damage entailing exorbitantly expensive repairs while reinforcing the almost universal notion that the pool owner must be mostly wealthy while the “engineer” who provides us with such technology --since he cannot read a clock--after work is tapped on the shoulder by his secretary who must then lead him to the door when his wife now drives him home

[ps558]

The Forum participant frustrated over the maintenance of his plunge may be interested in the following exchange to which I was privy owing to a lapse in Internet software security

But to summarize without requiring a busy Forum participant to read the entire exchange below can you help me out here: (1) Is my plan the usual way of handling the difficulty and (2) if it is, what would the unit be called besides just "pressure switch" and (3) could you recommend one, preferable carried by amazon.com.

On Feb 9, 2010, at 8:33 AM, Elad wrote:

As my Polaris booster pump is damaged if run dry for only a moment, entailing a massive repair bill, I'm wondering if you know of a pressure switch with a load capability of about 13 amps that would turn it on after the psi at the output of the main pump has reached, say, 15 to 20 psi. If you know who might carry such a device could you please send me some info about it—Thank you kindly—Elad

On Feb 10, 2010, at 5:27 AM, Sien Glensker [Elad’s fellow pool owner] replied:

Is it possible that the pump is running dry when the pool sweep accidentally moves up a wall surface high enough to get part of the head out of the water and thereby taking in air, which is causing your problem?

Hi Sien:

No, the Polaris operates under pressure from that auxiliary booster while intake to the main pump is derived from the skimmer port. However, when water level has fallen to near the bottom of this port some air is drawn in along with the water though it's hard to imagine the mixture could so damage the booster

But after a period of system disuse (during extended maintenance for instance) the tubing leading from skimmer to main pump partially empties owing to the latter—incredibly--being situated at a higher level so that when the system is re-energized it is unable to draw water, blowing the system full of air

I believe it can also be caused by failure to adequately tighten the cover of its input pump-basket vessel; air leakage here owing to a worn or damaged O-ring; a problem in some intermediate system such as an in-line chlorinator; if during maintenance you should happen to somehow energize the booster before the main pump…...

Under these circumstances the only way to restore the system to operation is to prime it with a big bucketful of water poured into the vessel, then quickly closing the vessel, remembering of course the O-ring. While doing so remember also to hold down the right side of your mouth with your left index finger while farting to the tune of Auld Lang Syne

Thus it's possible I had inadvertently left the booster on during one such episode causing it also to run dry with the consequent disaster

I'll never get over in this day and age of aerospace exploration and miraculous new invention how primitive are our pool systems wherein the tiniest flaw causes disastrous, irreversible damage entailing exorbitantly expensive repairs while reinforcing the almost universal notion that the pool owner must be mostly wealthy while the “engineer” who provides us with such technology --since he cannot read a clock--after work is tapped on the shoulder by his secretary who must then lead him to the door when his wife now drives him home

That is a good idea you have. There are pressure switches rated at 25 amps. Look at spa parts places, since most pressure switches are for the most part pilot duty it might need to be ordered. Another problem is while the pool pump is priming and is surging water and or air while priming it could cause the pressure switch to close and then open right away. Which will alot of stress on the contacts and the booster pump. You really should have a electronic countdown timer installed to the booster pump from starting until the pool pump is at full prime.

Instead of going through all this why not find out why the pool pump loses its prime. It should not do this or should recover very quick no matter how long the pool sat. Find were air is leaking in the system. They only other option is a pool control system

[ps558]

Installing A second timer will not do any good. Most times the air leak is located above the ground. It could be any glued, threaded fittings, valves orings, strainer pot lid oring. even a pump seal.

[dalehileman]

ps of course you're right again, such a timer wold help only if you could be sure the main pump is drawing. That's what I meant though apologies if I wasn't clear

Meantime I looked into spa pumps but the info given by the Amazon ads was of virtually no help whatever as you will see by my customer review in this link

http://www.amazon.com/Hayward-Models-Press...6222&sr=8-4

[ps558]

ps of course you're right again, such a timer wold help only if you could be sure the main pump is drawing. That's what I meant though apologies if I wasn't clear

Meantime I looked into spa pumps but the info given by the Amazon ads was of virtually no help whatever as you will see by my customer review in this link

http://www.amazon.com/Hayward-Models-Press...6222&sr=8-4

That one from amazon is for a Hayward Heater. Here is a 25 amp rated switch

http://store.poolcenter.com/shared/StoreFr...ELAID=425473897

[Pool Clown]

I'm not sure i'm understanding this. Are you saying that there is currently no time clock for the booster pump, and that it always comes on with the filter? And you want to add a pressure switch to ensure there is pressure to have the pump run correctly (with enough water)?

If i am understanding this, and please, let me know if i'm not...

First, the booster pump needs a separate time clock. If your system is loosing prime when you have not opened the system (i.e. to empty pump basket), you have a problem that needs to be fixed. Adding a pressure switch only treats a problem, it's not solving it. Also, keep in mind, a pressure switch does not know if the pressure is water, or air so that may not even address this problem but perhaps aggravate it. If it does have a switch, turn it off while you are servicing the filter pump.

There was mention of the space program, and how they can get past problems like this. They do it by eliminating the cause, not fixing symptoms, and we do that here too. A cleaner booster pump without a time clock is not only the wrong procedure, but costly as well (electrical use). Pool cleaners generally don't need to run nearly as long as the filter pump does, and should be controlled as such.

But after a period of system disuse (during extended maintenance for instance) the tubing leading from skimmer to main pump partially empties owing to the latter—incredibly--being situated at a higher level so that when the system is re-energized it is unable to draw water, blowing the system full of air

After rereading the first post again, it sounds like that if the pool owner would periodically check his water level and fill as needed, this problem of the system running dry shouldn't even be happening.

I have to be missing something here...

I'll never get over in this day and age of aerospace exploration and miraculous new invention how primitive are our pool systems wherein the tiniest flaw (I don't think letting your pool run low is a flaw of the pool design.) causes disastrous, irreversible damage (Makes it sound like he left the nuclear reactor on too long..."entailing exorbitantly expensive repairs while reinforcing the almost universal notion that the pool owner must be mostly wealthy or not able to operate a garden hose while the “engineer” who provides us with such technology --since he cannot read a clock--after work is tapped on the shoulder by his secretary who must then lead him to the door when his wife now drives him home

Wow, that was harsh...

Sounds to me that he got the idea that all you have to do is fill the pool and then wait till it gets warm enough to break a sweat then he can go to his pool, that he hasn't seen in weeks, or at least check to see if there is enough water in it, to go for a swim. Then back into his house, draw the shades, and wait to break a sweat again.

Pools work just fine when they have the recommended equipment. I don't think i have ever been to a pool that doesn't have a time clock for the booster pump. So i don't think i agree with the statement, "that's a lot of trouble and only another gadget I have to fool with".

I'm sure that it is me, and i'm missing something here.

[dalehileman]

I'm not sure i'm understanding this. Are you saying that there is currently no time clock for the booster pump, and that it always comes on with the filter? And you want to add a pressure switch to ensure there is pressure to have the pump run correctly (with enough water)?

Clown You seem to have grasped my idea

First, the booster pump needs a separate time clock.

Yes as I agreed in an earlier post this might certainly help but i I'm uncomfortable with the prospect of main pump failure, which your timer doesn't address

If your system is loosing prime when you have not opened the system (i.e. to empty pump basket), you have a problem that needs to be fixed.

That is certainly the case. However many other exigencies could cause the main pump to draw air as I pointed out, eg, pool surface level falling below skimmer outlet, a break in the tubing leading to the pump, a long period of disuse where the water in this tubing has evaporated etc etc etc

Adding a pressure switch only treats a problem, it's not solving it.

Why not? The switch would permit the booster to come on only if the input pressure to the filter was high enough to ensure at least moderate flow into the booster. Of course we're in trouble if the tubing between the filter output and the booster input should rupture but that's pretty unlikely

Also, keep in mind, a pressure switch does not know if the pressure is water, or air so that may not even address this problem but perhaps aggravate it. If it does have a switch, turn it off while you are servicing the filter pump.

I do that of course and in fact the booster can't come on if the master switch is off but that doesn't eliminate every contingency, eg, during normal operation if the main pump were to quit owing to say loose wiring, with your scheme the booster would keep running. Furthermore I believe you are wrong about the switch being unable to distinguish air from water. If the main pump is delivering only air, its pressure would drop far below the 15-25 psi required to close my pressure switch

........ booster pump without a time clock is not only the wrong procedure, but costly as well (electrical use). Pool cleaners generally don't need to run nearly as long as the filter pump does, and should be controlled as such.

As I pointed out above--with your scheme there are simply too many ways the booster could keep running even though the main pump goes off or draws air. Furthermore a separate timer for the booster pump might cost appreciably more than the switch

After rereading the first post again, it sounds like that if the pool owner would periodically check his water level and fill as needed, this problem of the system running dry shouldn't even be happening.

I have to be missing something here...

I think if you reread the pertinent posts as well as the above you will see that is indeed the case.

.......... I don't think i have ever been to a pool that doesn't have a time clock for the booster pump

That doesn't make it the best solution by any means. If your confusion has arisen from a lack of clarity on my part I once again apologize whilst hoping that now you comprehend my position

[Pool Clown]

Yes as I agreed in an earlier post this might certainly help but i I'm uncomfortable with the prospect of main pump failure, which your timer doesn't address

Sometimes pumps run dry. Its an unfortunate fact. Most of the time its owner related as in your case. As long as you continue to ignore the fact that your problem is not the booster, but the main pump loosing prime, you will have failures. It seems strange that you are more worried about "jury rigging" the booster with a switch rather than fixing the problem that is causing it.

If your system is loosing prime when you have not opened the system (i.e. to empty pump basket), you have a problem that needs to be fixed.

a long period of disuse where the water in this tubing has evaporated

If this something that happens overnight, you need to address the problem of the pump loosing prime instead of a workaround for the booster pump.

Adding a pressure switch only treats the problem, it's not solving it.

Why not? Because this does not fix the main problem!! It only treats the symptom. this is what i meant to say earlier.

The switch would permit the booster to come on only if the input pressure to the filter was high enough to ensure at least moderate flow into the booster. Of course we're in trouble if the tubing between the filter output and the booster input should rupture but that's pretty unlikely

If you fix the original problem, you wouldn't need a switch in the first place!

Also, keep in mind, a pressure switch does not know if the pressure is water, or air so that may not even address this problem but perhaps aggravate it. If it does have a switch, turn it off while you are servicing the filter pump.

I do that of course and in fact the booster can't come on if the master switch is off but that doesn't eliminate every contingency, eg, during normal operation if the main pump were to quit owing to say loose wiring, with your scheme the booster would keep running.

But how often do you think this would happen? Probably not nearly as much in the pumps whole life as what has happened to your pumps so far, due to another problem (filter pump loosing prime)

Furthermore I believe you are wrong about the switch being unable to distinguish air from water. If the main pump is delivering only air, its pressure would drop far below the 15-25 psi required to close my pressure switch

I doubt if you will get 15-20 psi downstream of the filter.

Question, are asking for advice here? or telling the professionals their wrong when we have the knowledge and practical experience in the field of the problem you are having?

........ booster pump without a time clock is not only the wrong procedure, but costly as well (electrical use). Pool cleaners generally don't need to run nearly as long as the filter pump does, and should be controlled as such.

As I pointed out above--with your scheme there are simply too many ways the booster could keep running even though the main pump goes off or draws air. Furthermore a separate timer for the booster pump might cost appreciably more than the switch

The time clocks can be wired in such a way that the booster won't come on unless the filter time clock is switched on. But that would probably be too much of a bother for you to do, as you pointed out earlier.

After rereading the first post again, it sounds like that if the pool owner would periodically check his water level and fill as needed, this problem of the system running dry shouldn't even be happening.

I have to be missing something here...

I think if you reread the pertinent posts as well as the above you will see that is indeed the case.

No, i think after reading again, that your only real problem is the pump loosing prime WHICH SHOULD BE ADDRESSED FIRST!

.......... I don't think i have ever been to a pool that doesn't have a time clock for the booster pump

That doesn't make it the best solution by any means.

If you mean by seeing hundreds, if not thousands of pools, and NEVER seeing your particular vision, you discount the idea of a time clock? Then i'm sorry, but i have noting more for you.

I hope you can get the system running the way you expect, but i don't think it will be possible. What you're looking for perhaps, is a control system that will give you an e-mail anytime the pool coughs. But that won't work because you won't want to fix it right, you'll look for a inexpensive workaround.

You should probably fill the pool in and plant Daisy's, I believe that will give you the carefree pool performance that you are looking for/expecting.

[dalehileman]

.....isn't there a single board participant using a water-pressure switch who might be able to recommend one having the specs I have outlined--thanks anyway though

Guys forgive me again for bubbling this back up but meanwhile in my vast ignorance about such matters I've encountered some more questions

A. What's meant in some ads by "low-pressure cutoff"

http://www.amazon.com/Square-FSG2J24M4CP-P.../ref=pd_cp_hi_1

B. Some ads give a range of pressure, eg, 40-60 psi. But I'm baffled by this as I had envisioned a pressure switch as closing at a preset value and remaining closed above that pressure, while opening when the pressure drops below it

Incidentally I agree that a flow detector would be a superior way of addressing my requirement but a typical pressure switch costs as little as $12 so you can see why I stick with this proposal

[quantumchromodynamics]

I did find the one rated at 25 amps but it operates at only 2 psi whereas I need one in the 15-20 psi range.

The switch closes at 2 psi and stays closed above that pressure. This switch would work for a pump wired for 120 volts that only needed to interrupt one leg of the supply. This could be put after the filter and should work fine.

For a 240 volt wired pump, you would need a double pole, single throw switch to interrupt both legs of the power supply.

For that, you should use a contactor relay. You could use any pressure switch as the control to the relay. The pressure switch would not need to be rated to the current of the pump since the contactor, not the pressure switch, would be carrying the current.

Note: It is important to make sure that all work complies with all applicable codes and standards.

[dalehileman]

"The switch closes at 2 psi and stays closed above that pressure. This switch would work for a pump wired for 120 volts that only needed to interrupt one leg of the supply. This could be put after the filter and should work fine."

Thank you quant for that suggestion. It had never occurred to me connecting the switch at the output of the filter. However, have you actually tried this? I'm not sure it would work "fine" because the instant the booster comes on, wouldn't the pressure drop to zero or even to a slightly negative value, causing it to shut off. Thus the booster would be repeatedly switching itself off and on

"For a 240 volt wired pump, you would need a double pole, single throw switch to interrupt both legs of the power supply."

This is definitely the safest way to go. However in a 240-v system where both sides are above ground, a single-pole switch in just one side will work just fine. Of course for subsequent servicing you'd have to make sure to shut off the main breaker back in your house lest you electrocute yourself

[quantumchromodynamics]

Yes, you are correct that the pressure might be too low if the switch were to be placed after the filter. I thought about that afterward and I was going to make a correction about that. It would be better to put the pressure switch before the filter.

Gas heaters and heat pumps work like this, they are after the filter and they have a pressure switch to ensure that they shut down if the flow* suddenly stops. I have had a few issues with heaters not wanting to come on when the Polaris came on due to the lower pressure. In that case, a flow switch can be used instead of the pressure switch.

I think that your best option is to use a double pole, single throw contactor and to use a simple pressure or flow switch to control the contactor. I don't agree with using a single pole switch on 240 volts.

*Heaters use a simple pressure switch as a "flow" switch, which usually works, but not always.

[Cal-Hyper]

Even if the main pump failed, the booster pump would still draw water from its source. As long as the valves are still open, the water is still above the skimmer, and the suction side lines are not compromised.

[dalehileman]

I don't agree with using a single pole switch on 240 volts.

Quant I don't blame you and I advise all against it, especially if you bring in outside help as your contractor could electrocute himself. However I'm lazy and hope to minimize cost

Even if the main pump failed, the booster pump would still draw water from its source.

Thanks for the tip Cal and I understand the theory but you'd be taking an awful chance since there ae so many ways the main flow cold be interrupted or air introduced.. I'd think also for instance that if the main pump failed and the filter were badly clogged or its impeller put up quite a bit of resistance then even if continued flow were possible and the system were still airtight the obstructions might overload the booster

Incidentally I wonder if this one--just $11.40--might work

http://www.amazon.com/gp/product/B000HE6DX...;pf_rd_i=507846

though actuating pressure is a little higher than I would like. However ads such as this are terrible by not supplying enough information: For instance this one doesn't even give load capacity nor does it specify whether NO or NC

[txpoolguy]

Dale, it sounds like most of your questions and points are valid, but perhaps you're overthinking this. The dual timer system has been used very successfully for decades. Yes, the pressure switch could benefit, but you may end up spending more money for very little advantage.

Cleaner pumps are not "self-priming" pumps, as your main pump is. "Self'priming" is not meant to indicate that it will always prime itself, rather that with MOST situations, it will. Proper maintenance is the primary factor in these failures, although sometimes that's not enough. There is a "cost of ownership" that exists with your swimming pool equipment, as with other things such as automobiles, homes, televisions, toasters, etc.

Technology does offer us the ability to make pumps that are less susceptible to dry-run, but it costs more. You (and most other people as well) usually buy the cheaper pump, thereby eliminting the market for the more expensive pump. Your posts indicate that you don't want to spend the money on a 2nd timer, so you you probably wouldn't spend an extra 200 on a different design of pump.

The repair you refer to could not have cost more than a few hundred bucks max, so I must laugh at your reference to space exploration, etc. You might note that we didn't get to the moon and back for $300.00. Yes, technology exists to do many things, but most of us would blanch at the cost. You may recall that a gasket failure once caused the loss of a space shuttle. That gasket likely cost 100K or more. The gaskets on your pool system cost just a few dollars, and can be expected to fail from time to time. If you feel that the product isn't as good as it should/could be, I'd remind you that, in a free enterprise system, you're welcome to design and market a superior product and become a self-made billionaire.

Most issues of failed equipment in our industry can be eliminated by 1. Proper installation, and 2. Good maintenance. Please don't blame the designer/engineer. Your statment of "I'm lazy and hope to minimize cost" points to the main reason that equipment fails - not just in your yard, but across the world. We all suffer from that flaw.

The key is to understand that you're getting a good product, and to maintain it per manufacturer's suggestions. This is all that any of us can do. There will be the cost of ownership and maintenance, but there is no product on the face of the earth that does not require regular maintenance and repair.

Good luck

[dalehileman]

abcd

[dalehileman]

txp thank you for these observations

......The dual timer system has been used very successfully for decades.

Yes but it's of no value should the main pump lose prime. With my proposed system nearly any failure upstream of the filter would turn off the booster. Your second timer is of no use if the booster should go dry for almost any reason whatever then self-destruct

Yes, the pressure switch could benefit, but you may end up spending more money for very little advantage.

I hope to have a far superior system for about $12

Cleaner pumps are not "self-priming" pumps, as your main pump is. "Self'priming" is not meant to indicate that it will always prime itself......

Forgive me if I was not clear but I never said it would. In fact, even if it could, without additional protection such as I propose almost any upstream failure would deprive the booster of water so in the conventional system it would go dry anyhow

.......You don't want to spend the money on a 2nd timer, so you you probably wouldn't spend an extra 200 on a different design of pump.

I won't need to, if I can only find the right switch

The repair you refer to could not have cost more than a few hundred bucks max

About $100. However if the malfunction occurs once a year I would have spent $2000 over the period during which I hope to live

............I'd remind you that, in a free enterprise system, you're welcome to design and market a superior product and become a self-made billionaire.

In fact I am an erstwhile writer and inventor but the time and cost today of finding a publisher for my book or a sponsor for my inventions might far exceed any returns so I offer the Pool Establishment my pressure-switch invention gratis, only hoping it gives me some kind of credit: "The Hileman Boost Protector"

Most issues of failed equipment in our industry can be eliminated by 1. Proper installation, and 2. Good maintenance.

Alas txp, the latter might entail you running out to your pool for inspection five times a day for 20 years

Please don't blame the designer/engineer. Your statment of "I'm lazy and hope to minimize cost" points to the main reason that equipment fails - not just in your yard, but across the world. We all suffer from that flaw.

Sorry if you happen to be one of them but I still consider the Pool Engineer grossly incompetent by comparison if he considers his second timer superior to my simple pressure switch

The key is to understand that you're getting a good product,

I'm not

..........and to maintain it per manufacturer's suggestions. This is all that any of us can do.

Except me, I invent a better way

There will be the cost of ownership and maintenance, but there is no product on the face of the earth that does not require regular maintenance and repair.

Yes but one can minimize such needs by intelligent design of which the Pool Establishment is notably lacking

Good luck

Thank you txp. In spite of our disagreements I judge you must be a really fine fellow and I'd be most happy to discuss nearly anything being dalehileman@me.com

[waterbear]

DO NOT FEED THE INTERNET TROLL!

However, you might be interested in the following about this poster:

Read this. (If you wonder why keep checking out the links)

and this (thread was locked)

and this

and this

and this (This one is a must read!)

and this (This also, he got banned on this board for three days in this thread)

and this

and this

and this (thread was locked)

and this

and this

and this (this is a good example, the thread got locked. Be sure to read the second page also!!)

and this

and this (be sure to read down to the last three posts on page one and the posts at the top of page two, they say a LOT. This thread was locked also!))

There are many more examples.