Sump Pump Help

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Jeff Handy

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It sounds like his 1/3 hp pump, being discharged through a skinny garden hose, is pumping out the pit much faster than his 1 hp pump.

I assume his main discharge is at least 1-1/2 pipe.
So it sounds like there is likely a defect in the discharge line.
Which is something I tried to bring up earlier.

Just last weekend, I rodded out a buried 3 inch discharge line that tended to freeze and clog during the polar vortex weather.
Even though it was set up to drain to daylight and not hold water.
A pipe joint near the end had blown apart, the rubber coupling had rotted and failed, and water was just bubbling up through the dirt, not from the end of the drain that seemed clear and open.

Or his check valve is defective, or maybe the spring flapper is broken loose inside.
 

Sunho Choi

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It's not doing you much good to try to compare it to a different pump that has a different HP, likely different efficiency, and possibly different pumping elevation head conditions. Not to mention likely a smaller diameter(hose). Too many variables unless you consider all factors, including the pumps characteristic curve(flow vs head would be different).

By the way, before I forget, one of the pump persons that has a lot of videos and id in the business I believe, passed on the info that the rule of thumb is a 1 HP or less motor requires @ least 1 minute running time. ( Not sure how this relates to motors restarts per hour when you don't know duration of off time.)

Of course, when you try to time the pumped flow while there is inflow, you must add the inflow rate to the calculated outflow rate.
I believe I mention something along the lines that you could time your typical or few inflow rates while the pump is NOT running. Then you would know what to add to the outflow rate.

You never said what size pipe you have. I was going to approximate some numbers when I had asked about the elevation where the PRESSURE pipe terminated and friction lost stopped play a role on head loss.

To confuse you further, I have to mention that the total discharge head is not to the highest point of the discharge pipe but to the point where it dumps into a gravity line or sees atmospheric pressure. For example if the discharge pipe went up 10 feet and then turned down for say 2 feet, the total elevation head would be 10 - 2 = 8 feet.

We should be dealing with the actual performance curves for that pump or develop our own system head curve based on recording actual flow rates and elevations.

But Like I said what exactly are you looking for?
1. The pumps maximum discharge flow rate should at least match the maximum in flow rate.
2. You want enough capacity in the sump to to keep the motor restarts down to an acceptable number.
So if I'm calculating correctly, my inflow rate is 3.8 gpm. My pumped rate would be 7.6 gpm or maybe a little more?
My total elevation head which I previously thought was 9-10ft, should be that + 40ft since it runs horizontally about 40ft before the pipe drops down at the downspout line.

Would those numbers make sense? Also the pipe size is 1.5"

I guess I just want to make sure my set up is working properly and there is no underlying issue that is affecting the performance.
Also I don't quite understand where the proper water level should be.
For example why is the water streaming into the pit from the inlet?
Is it ALL from water from the last rain that is trying to drain?
Is it that my water table is higher and I'm just trying to pump water from the water table?

And finally, I know you don't want me to compare, but I still don't understand how a 1/3 hp pump using a hose which is less than half the diameter of a pvc pipe can pump water out faster than a 1hp with a larger diameter. They both have to go up the same height, but one just travels horizontally about twice the distance.
 

Sunho Choi

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It sounds like his 1/3 hp pump, being discharged through a skinny garden hose, is pumping out the pit much faster than his 1 hp pump.

I assume his main discharge is at least 1-1/2 pipe.
So it sounds like there is likely a defect in the discharge line.
Which is something I tried to bring up earlier.

Just last weekend, I rodded out a buried 3 inch discharge line that tended to freeze and clog during the polar vortex weather.
Even though it was set up to drain to daylight and not hold water.
A pipe joint near the end had blown apart, the rubber coupling had rotted and failed, and water was just bubbling up through the dirt, not from the end of the drain that seemed clear and open.

Or his check valve is defective, or maybe the spring flapper is broken loose inside.
I have some exciting news to report! I called rotorooter and had them come out this afternoon. They snaked the gutter line going to the creek and also the sump discharge line that connects to the gutter line. Plugged my sump back in and now it pumps out the water in a hurry! WOW what a difference. Looks like I should be cleaning out these discharge lines once every so often since I have so much iron ochre here. My next step will be getting a hi/lo switch so that I can adjust the run time to be longer as to not short cycle the pump.

Thanks Jeff and DieHard for helping me through this!
 

Jeff Handy

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I will put on my “clogs” and do a little happy dance, haha.

But seriously, if the sump is sharing a drain with the house gutters, that line could be choking up with leaves, and also leaves that rot and turn into muddy compost up in the gutters.

So keep the gutters clean, and also you can install a filter.
Either up in the gutter, just before the downspout, or right at the bottom of the downspout just before it dumps into the drain line to the creek.
You can find these on Google.
They let water through, but they hold back sticks and leaves.
Some of them need regular cleaning, and other types are at least partially self cleaning.
 

Jeff Handy

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Not sure what that means.

But a tight connection would not be needed, if everything runs away freely by gravity, unrestricted.

I assume the 1-1/2 inch sump discharge joins up to a larger drain which also accepts the downspout.

But my point was to try to keep leaf debris from entering and clogging the shared drain, which drains both the downspout and sump discharge out to the creek.
 

Diehard

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No, I'm just saying when the OP was describing the pumps discharge piping arrangement, I was trying to obtain the TDH( Total Dynamic Head).
He mentioned "it left the house, angled down and connected to the gutter drain spout where it connected to an underground pipe that runs about 60ft to a storm water creek." So when I heard this description, while I'm trying to figure out the exact hydraulics affecting the pumps performance, I made the assumption(wrong apparently) that the connection to the gutter drain spout was the end of the force main(Or the hydraulic calcs.).
I wasn't thinking that it may be all backed up due to blockage and so on. I was still thinking about the hydraulics and never really got that far.

My problem is, I used to engineer pumping and piping systems and like to get into the detail stuff.:Do_O
 

Jeff Handy

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Yes, I understand.

Once you have the discharge flowing downhill, and entering a larger pipe, you would rightly think that it would basically be like just dumping on the ground at that point.
No more pipe friction or back pressure to worry about from that point on.

I tend to think of more doom and gloom scenarios, outside the box as they say.
 
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