The Best Method To Control a Lake Pump:
 
Get better performance, significantly extend the life of your lake pump, and reduce the probability of accidents

 

Now customers can "have their cake and eat it too".

 

For those who need maximum convenience, we are the only company in all of Texas offering the ultimate system. Many customers prefer to have an extra faucet(s) for washing down boats, docks, decks, water slides, etc. with lake water.  We have engineered and offer a combined system that virtually eliminates the constant wear and tear of pump cycling during irrigation. The key difference is our system also gives maximum continuous pressure without cycling to the sprinkler heads which ordinary pressure tank/pressure switch systems don't do.

 

Furthermore, this combined system allows for simple "turn on the lake water faucet" anytime and receive lake water as needed. This combined system is especially useful for those customers using a single pump to supply lake water to both an irrigation system and also domestic water inside the home.



For those who use their lake pumps to provide lake water to an automatic sprinkler system  - -  or, to supply an automatic sprinkler system plus domestic water for the home - - the best method to control the pump for the irrigation cycle is not the ordinary pressure switch and pressure tank alone installed by all water well companies as well as less knowledgeable pump companies.

In fact, their pressure switch method of control alone has several disadvantages.

So why do water well companies and less knowledgeable pump companies still use this method ?

A knowledgeable authority at one of our pump suppliers told us it's because of at least 4 reasons:

1) The ordinary pressure switch/pressure tank method alone has always worked for these companies
2) They stand to make extra money off replacing pumps and other hardware which wear out faster than normal through constant cycling.

3) They just don't know any better.
4) Water well companies as well as unlicensed installers are forbidden by Texas law to connect any of their hardware to irrigation controllers.

So let's look deeper at some of the disadvantages of having a lake pump controlled solely by a pressure switch / pressure tank feed water to an automatic sprinkler system:

A) With the ordinary pressure switch/pressure tank method of control on most all existing systems, all the hundreds of feet of sprinkler piping mainline throughout the front and rear yards are under full pressure 24/7/365.  That's all the time. 

If a crack or leak develops anywhere, or any one of the underground sprinkler valves fails to close  - - you have a runaway leak until it's noticed (we get an awful lot of service calls for this).  If the property owners happen to be away on vacation or business then the pump runs continuously running up the electricity bill. The worse risk is if the waterfront property is a 2nd home whereby the property owners are gone most of the time. What if the leak is upstream of the septic system and the septic field gets flooded, then the property owners show up for a nice weekend at the lake and their toliets don't flush well ?

Certainly there is an add-on device that can help with this problem, but installing it on already existing systems requires digging up the lawn, costs more money $$$ and it adds another 4 psi typical pressure loss (adding further insult to injury). The vast majority of all the existing systems we encounter don't have this device.

B) Pressure switch operation relies upon the pressure switch sensing the water pressure. When the pressure the system drops below a preset such as the most common switch setting of 40 psi, the pressure switch activates the pump and the pump slowly builds pressure back up to the 60 psi cut-out. While it's possible to adjust the pressure switch range from 40 to 60 psi up to 50 to 70 psi, or even higher, adjusting the range up actually reduces the capacity of the pressure tank air bladder, effectively increasing the amount of cycling on the pump.  So, then you start considering a larger pressure tank or even more than one tank $$$.

The #1 item that wears out pumps the most is constant cycling, turning them on and off, which is exactly what pressure switches do very well.
Our superior method of control allows the irrigation controller to take first priority over controlling the pump during the late night irrigation cycle so that the pump is turned on one time at the start of the irrigation cycle - - and turned off once at the end of the several hour irrigation cycle.   With just a pressure switch / pressure tank method of control the pressure switch will cycle the pump hundreds of times over an entire irrigation cycle. Now, multiply that times as much as 150 to 350 or more times per year and you quickly realize the difference.

C) The "range" effect caused by the pressure switch method of control is the worst way to provide optimum pressure to the large rotary sprinkler heads that water the large turf areas of a landscape. Even if your pressure at the pressure switch and tank area is starting out at a typical value of 60 psi, by the time the water winds it way through all the pipes, fittings, valves and restrictions you are lucky to have only a 10 psi loss  -  which equates to 50 psi actually available at the rotary sprinkler head.

Well, most rotary sprinkler heads give their best performance at 60 psi at the head, and 70 psi is even better. Now, most irrigation installers design and install their sprinkler systems at standard head spacing which is often based on about 60 psi pressure at the rotary head (such as from a relatively constant pressure water source like a water meter). They usually don't take into account the varying range of a pressure switch controlled source of water. Very rarely do we encounter sprinkler systems designed and installed with reduced rotary head spacing to account for the low water pressure problems caused by pressure switch control.

So, lets be optimistic and choose a hypothetical high side of 70 psi. What do you think happens when the sprinkler system activates with a tank pressure at even 70 psi ? The system pressure drops down until it reaches the pressure switch cut in of say 50 psi where the pump is energized to start pumping all over again. Once (if) the pump is able to reach the 70 psi level the switch shuts off power to the pump.

However, with the very large flow of water to a sprinkler system, in usually less than a minute though the system pressure drops back down to 50 psi and the cycling process starts all over again.

Now consider this. When the sprinkler system was activated, the system pressure was at a given value of 70 psi, and we know that we have at least 10 psi friction losses through all the pipes, valves, fittings by the time water pressure reaches the rotary sprinkler head. That yields a net of 60 psi at the actual rotary sprinkler head which is reasonable. But that "high side" pressure lasts only seconds because as the pressure starts dropping lower and lower the water pressure at the rotary sprinkler heads suffers, and the pressure reaches as low as 50 psi minus the 10 psi friction losses = only 40 psi, way below rotary sprinkler head manufacturers recommendations for the head spacing on site. 

The bottom line is that for pressure switch control, between the high side pressure and the low side pressure is a bell shaped curve where at least 50% of the time the overall water pressure available to the rotary sprinkler heads is substandard, often resulting in poor performance.

But our example above was for a modified pressure switch setting, so now you can just slice another 10 psi losses from the above example off the standard, typical, unmodified 40 - 60 psi pressure switches that all water well companies as well as less knowledgeable pump companies install.

In most circumstances, lake pump installers are trying to conserve and use the maximum pressure / flow from the lake pump.

What about the famous cycle stop valves ? These are NOT recommended by major pump manufacturers (this valve voids their pump warrantees). Well, charts show the CSV1A cycle stop valves have a rather large pressure drop across them of at least 10 psi loss at the ~20 gpm flow of a larger rotary head zone of a sprinkler system. The alternative with less pressure loss is the thermoplastic cycle stop valves, but they are not rated for systems operating above 60 psi and will eventually start leaking through a port when used with dirty lake water. Yes, lesser pump companies who put your pump warrantee at risk and are not trying to maximize pump pressure and performance install cycle stop valves. Yikes, just when we were trying to make sure we have all the pressure we can get  - -  the popular cycle stop valve can easily take away 10 psi or more pressure !

But what about variable frequency drives
to control pumps ? This is what pump manufacturers introduced several years ago to supposedly solve pump cycling problems (and boost sales of an expensive new device). Some insiders say there were some "private discussions" at the time between pump sales reps and water well company owners about how much extra money they could make selling these new variable frequency drive pumps to customers.

Well, we have come to regard these variable speed drive pumps sort of like modern cars with all the fancy electronics and expensive gadgets.  In the Texas heat these fancy boxes full of complex electronics often fail early (average cost around $2,000 just for the electronics). Coincidentally, the pump manufacturers have reduced their initial warrantees shorter and shorter.   There have been so many problems with variable frequency drive systems we avoid installing them like the plague. Good old fashioned single phase pumps have worked for decades and that is what we recommend.

Especially in situations where the lake pump system was installed with an ordinary pressure switch / pressure tank method of control  - -  and is only feeding an automatic sprinkler system, property owners really have no good reason not to convert over immediately to our solution. You can simplify your "irrigation only" system if you don't need a extra water faucet - - - as you don't even need a pressure switch and a pressure tank.

All in all, contact us if you want the most reliable and best engineered solution for your lake pump system that allows your system to perform best as well as prolongs the life of your pump.