Sump pit depth?

I like in an area with a high water table. We recently flooded during Hurricane Irene and are putting a second pit in on the opposite corner of the original pit. The original pit is only about 18" deep and normally the pump only turned on during heavy rains and there wasn't a problem except for the hurricane. The new pre-fab pit the contractor bought is much deeper (probably about 36"). Question: is that too deep and will the pump run all the time? If the pit is fed by the drain tile line and is solid on the bottom, does it matter? Won't it only fill up when the water level is up to the drain tile level? Should water be able to enter the pit through other holes in the pit?

Thanks for your help,
SN

We would have to see the prefab pit and where the static water level sits in the hole for the pit before we could answer whether or not the pump will run all the time. If your prefab pit has no holes in it, it would fill only from above. You can set the pump at any depth you choose and you can adjust the float to turn the pump on and off at any height of your choosing providing you buy such a pump.

luxhhykh@sharklasers.com said:

The new pre-fab pit the contractor bought is much deeper (probably about 36"). Question: is that too deep and will the pump run all the time?

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After the pump has discharged water down to the float level, it will only run after water again raises the float ... and the deep pit (sump) will allow the pump to run longer each time it *does* run rather than to have its life shortened by continual on/off "short cycling" (such as with a low-volume sump).

luxhhykh@sharklasers.com said:

If the pit is fed by the drain tile line and is solid on the bottom, does it matter? Won't it only fill up when the water level is up to the drain tile level? Should water be able to enter the pit through other holes in the pit?

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Codes likely dictate the solid bottom, and it really does not matter how water gets into the sump.

luxhhykh@sharklasers.com said:

How would the deeper pit allow it to run longer? It's on when the float is at a certain level, off at a different level, there's a about 6" of travel of the float so it run would long enough to empty 6" of water. Right?

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If you have a pump that has an adjustable range, it could be adjusted to run longer and cycle less often. Why limit it to 6" of range?

Also, some people will set the upper limit high enough that the drain tile itself is storage.

luxhhykh@sharklasers.com said:

How would the deeper pit allow it to run longer?

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By allowing physical room (volume) for the upper and lower float settings to be farther apart like LLigetfa has mentioned.