Sump pump

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infinity

infinity

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petersonra said:
This is for someone sump pump in their basement. A pump that's running 10 seconds on and 10 seconds off is running half of the time and that would seem to be way undersized either for the sump pump itself or the sump, or there's just way too much water getting into the sump.
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If the pump is cycling on and off then it's not too small but you're correct that there is simply too much water entering the pit. That can happen around here where the pump won't run for months but get a few storms in a short period of time and it will cycle for up to a day.
 
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GoldDigger

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petersonra said:
This is for someone sump pump in their basement. A pump that's running 10 seconds on and 10 seconds off is running half of the time and that would seem to be way undersized either for the sump pump itself or the sump, or there's just way too much water getting into the sump.
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A pump that is running 10 seconds on and 10 seconds off is not going to last very long IMHO.
 
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VirutalElectrician

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infinity said:
Around here also a normal operation depending on the height of the ground water and the time of the year. The Liberty pump that I have uses a slide float switch mounted to the side of the pump so the water only needs to raise a few inches and it will cycle on and off. When the ground water level is high the pit can refill in just seconds. One solution is put a external float switch mounted about a foot above the pump which has an adjustable timer so that it will run even after the float switch is off. This allows the pit to fill to a much higher level before the pump turns on.

After very heavy rains it may run for a few days before going back to normal. During Ida it ran continuously for about 24 hours just staying ahead of the overflow.
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Yup, just because others haven't seen or experienced this, doesn't mean it's an abnormal condition. You just need to have a spare pump on hand and/or replace it as preventative maintenance every 5 years or so.

Water level alarms and/or sensors connected to a smart home system is also wise.
 
kwired

kwired

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retirede said:
50% duty cycle isn’t terrible, but the sump should have more capacity to reduce the cycle rate.
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An hour on followed by an hour off is also 50% duty cycle, yet not really the same thing.

3 starts per minute heats up motor more than one start per day.
 
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VirutalElectrician

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retirede said:
Bigger than that.
Here’s how to calculate the whole shebang:

https://www.hydrosphere-engineering.com/Hydrosphere Sump Pit Volume Sizing Example.pdf
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I've never seen a custom sump pit in a house. Everything I've ever seen uses something like this:
https://www.menards.com/main/plumbi...sump-basin/psu1011/p-1444436214906-c-8598.htm

To go deaper, just means your digging more into the water table, which would cause obvious issues. Going wider is just going to take up more basement space. That formula maybe great if you're pumping year round, but not practical when it's only need 2-4 weeks out of 52.

Most of those little 1/2 - 3/4 sumps only have about a 6" slide on the float, so probably designed for lots of cycling anyways.
 
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tthh

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It may be the pump is not properly located in the pit. You see a lot of pumps sitting on top of bricks or tile. I think if the pump is too high up from the incoming drain pipes, it will cycle on and off more frequenty beacuse it is just accounting for the water in the pit itself that is above the incoming drain pipes. If it sits lower, it will pull the water from the drian pipe more directly and run longer, but less frequently.
 
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GoldDigger

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tthh said:
It may be the pump is not properly located in the pit. You see a lot of pumps sitting on top of bricks or tile. I think if the pump is too high up from the incoming drain pipes, it will cycle on and off more frequenty beacuse it is just accounting for the water in the pit itself that is above the incoming drain pipes. If it sits lower, it will pull the water from the drian pipe more directly and run longer, but less frequently.
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But actually at the very bottom of the pit may expose the pump inlet to sediment and other crud in the sump. And may block the suction opening(s).
 
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tthh

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GoldDigger said:
But actually at the very bottom of the pit may expose the pump inlet to sediment and other crud in the sump. And may block the suction opening(s).
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That's true....it just may be up a lot higher than it needs to be...I've seen this more than once.
 
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VirutalElectrician

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tthh said:
It may be the pump is not properly located in the pit. You see a lot of pumps sitting on top of bricks or tile. I think if the pump is too high up from the incoming drain pipes, it will cycle on and off more frequenty beacuse it is just accounting for the water in the pit itself that is above the incoming drain pipes. If it sits lower, it will pull the water from the drian pipe more directly and run longer, but less frequently.
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But if you're using the type of pump that only has 6" or so of movement sliding on a rod, what difference does it make where it sits?

And if the float is the hanging on a cord type, if you make it too long, it can tangle around the pipe. You're limited on space no matter what you do, and hence water volume.
 
Sea Nile

Sea Nile

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Georgia
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VirutalElectrician said:
But if you're using the type of pump that only has 6" or so of movement sliding on a rod, what difference does it make where it sits?

And if the float is the hanging on a cord type, if you make it too long, it can tangle around the pipe. You're limited on space no matter what you do, and hence water volume.
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Some pumps are designed to continue running for a set time after the float is back at the bottom. My battery backup pump for example runs for about 60 seconds longer after the float is all the way down. This float is not rigidity attached to it. It's built in-line with flexible wire so I put the float high up. It won't kick on unless my primary fails and the water gets to that level. Or i suppose if the primary can't keep up (more water in than out) it will kick on then I have two pumps actively pumping out water.
Screenshot_20220829-200036~3.png
 
kwired

kwired

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Location
NE Nebraska
Sea Nile said:
Some pumps are designed to continue running for a set time after the float is back at the bottom. My battery backup pump for example runs for about 60 seconds longer after the float is all the way down. This float is not rigidity attached to it. It's built in-line with flexible wire so I put the float high up. It won't kick on unless my primary fails and the water gets to that level. Or i suppose if the primary can't keep up (more water in than out) it will kick on then I have two pumps actively pumping out water.
View attachment 2561965
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Simple setups with float control in line with the motor have no delays. They instantly turn on or off when water level causes float to hit upper or lower setting. You need more advanced controls if you want delays in the operation scheme.
 
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