pressure switch for river irrigation? suction pipe

[DPForumDog]

We have had a Red Lion RL-SPRK200-BR sprinkler pump. It has done a pretty good job for the last 5 years as it pushes water from the river 700 feet up a 20ft incline, and to a garden near the lake pump house. . We use this pump 3 days a week during warm weather for about an hour at a time.

One small problem we have had is that it sometimes cuts on and off every minute. I read if it a 3HP pump it should stay on for at least 2.5 minutes.

Here is our newest big problem: Our current (newly purchased, only 4 months old, digital) pressure switch stop working so we removed it from our plumbing, It is a pain to operate it manually. We discovered the pump was not running so we went to pump house there was water all over the floor and the pressure switch was full of water. There was a 2ft collapse of the 4ft schedule 40 pvc on the suction side. We removed and bypassed the pressure switch and the pump turned on but there was a tremendous leak on the out-go side, and it seemed it may have slight puffy on the out-go side, but that could be my imagination because I read that was often the case when there was a collapse of the in-go suction pipe.

We want to buy a new pressure switch, but before do I want to make sure it is the best one for us.

1, How do we know what the proper cut-on pressure and the cut-off pressure for our needs so we can adjust it accordingly?

2. Will cut-on and cutoff pressure be different because we push water up a hill 700ft/20ft slope?

3. Does both cut on and cutoff pressure wok? I read that a pressure switch is either high pressure or low pressure but not both.

4. What are the disadvantages of a digital pressure switch?

5. I read that the first 12” of of suction pipe and first 12” of out-go pipe should be steel. Is that true?

6. Is the pressure switch the only way to protect the pump? I read where some suggested venting it.

7. We need a 3HP 240 V…. Suggestions? As there are not that many options. I read where some guy said it doesn’t really matter if the pressure switch matches the HP of the pump or the 240V.

8. Anyone have a diagram of how to properly plumb a sprinkler irrigation lake or pond pump?

I appreciate any and all responses

Granny DP
DPForumDog

 

[DPForumDog]

P.S. we did get a pressure tank 5 years ago and the irrigation system ran smoothly for over 5 years. I think this new big problem happened when we replaced our old pressure switch.

 

[Sponsor]

 

[Reach4]

7. We need a 3HP 240 V…. Suggestions? As there are not that many options. I read where some guy said it doesn’t really matter if the pressure switch matches the HP of the pump or the 240V.

Pumptrol pressure switches FYG/FYW are maxed out at 3hp 240 volt. FSG/FSW max is 2HP.

So https://www.supplyhouse.com/Telemecanique-9013FSG2J24-Pressure-Switch-40-60-PSI-10-Amp-DPST would not be suitable to drive the pump directly. HOWEVER if you have a "Deluxe" control box, that would have a relay/contactor that actually drives the pump, and the pressure switch only controls the relay -- much less power handling to do that.

Are you pumping 20 gpm, 50 gpm, or what? To avoid cycling, match the emitters to what the pump can do, or use a CSV to let the load be more variable.

 

[Valveman]

That pump shows to be 2HP and has a max pressure of 47 PSI. Sprinkler pumps don't build enough pressure to work with a pressure switch. 20/40 is as high as you can go with a pressure switch on that pump. Trying to get to 47 or 50 PSI is what gets the pump hot. The regular FSG2 pressure switch will work with that 2HP. But it will take a GHG2 switch to handle the current from a 3HP load.

You are losing 10 PSI going up the 20' incline. I don't think you need a 3HP. You need a 1.5HP or 2HP jet pump that can build some pressure to work with a pressure switch and push up that 20' incline. Sprinkler pumps are made to deliver high volume at low pressure. That pump is made to do 60 GPM, but only at 20 PSI.

How many GPM's are you needing?