Background:
I recently bought a house with a 1600 sqft basement (floor is 7 feet below the ground level). Two weeks ago there was a lot of rain and the basement had 4" of standing water within a few hours. It turned out that the old sump pump (a Simer 1/2 HP, 1900 gph @10 ft) stopped working. The water receded within 24 hours, but the sump pit was still almost full.
After reading online forums, I decided to replace the pump with a Zoeller. Today I installed a Zoeller M98 pump in the pit. This pump is sitting on a layer of bricks at the bottom of the pit. It rained yesterday, so the pit was almost overflowing today before I installed the pump.
When I turned the pump on the first time, it took 45s for the pump to lower the water level in the pit and then turn off. After that, there was an alternate cycle of the pump turning on, and off (water was rushing into the pit from the drain pipes while the pump was off). At first, the pump on time was about 10s and the off time was 12s. About an hour later this went down to an on time of 8s and an off time of 20s.
The diagram below shows the water level in the pit when the pump turns on. It also shows the pit dimensions (18" diameter and 22" deep), the drain pipe heights from the bottom of the pit (9" and 10"), and the water levels at which the pump turns on and off (11" and 6"). I believe the drain pipe on the right (9" above the pit base) has a much longer run than the other drain pipe.
As you can see in the diagram, the pump does not turn on until there is about 11" of water in the pit. Since the drain pipes are 9" and 10" above the pit base, the pump does not turn on until there is some standing water in the drain pipes.
Questions:
1. Do I need to adjust the pump float switch so that the pump turns on before the water level in the pit reaches the drain pipes? This way, the drain pipes won't have 1-2" of standing water in them before the pump turns on. In a slow season, it may take a few days for this much water to seep in the drain pipes. This means that the drain tiles below the basement floor could be quite wet before the sump pump even turns on. If I should reduce the turn on height, how would I do this? Options I can think of are to put a spacer at the top of the float slide bar, and also to replace the bricks at the bottom with something of a lower height.
2. Would the Zoeller M53 be a better fit than the M98? I am concerned that the M98 pump may be too powerful and so cycling too much. The water discharge is about 10 feet above the pump outlet. Since the M53 would take longer to empty out the pit, the incoming water from the drains may just keep that pump from turning off at all. The M98 is 1/2hp and pumps 3600 gph at 10 feet. The M53 is 1/3 hp and can pump 1900 gph at 10 feet. I do plan to finish the basement soon, and so don't want to have a situation where there is heavy rainfall, and the sump pump is not powerful enough to keep up with the heavy rain. Of course I don't want to see the pump cycling too much and burning up either.
I recently bought a house with a 1600 sqft basement (floor is 7 feet below the ground level). Two weeks ago there was a lot of rain and the basement had 4" of standing water within a few hours. It turned out that the old sump pump (a Simer 1/2 HP, 1900 gph @10 ft) stopped working. The water receded within 24 hours, but the sump pit was still almost full.
After reading online forums, I decided to replace the pump with a Zoeller. Today I installed a Zoeller M98 pump in the pit. This pump is sitting on a layer of bricks at the bottom of the pit. It rained yesterday, so the pit was almost overflowing today before I installed the pump.
When I turned the pump on the first time, it took 45s for the pump to lower the water level in the pit and then turn off. After that, there was an alternate cycle of the pump turning on, and off (water was rushing into the pit from the drain pipes while the pump was off). At first, the pump on time was about 10s and the off time was 12s. About an hour later this went down to an on time of 8s and an off time of 20s.
The diagram below shows the water level in the pit when the pump turns on. It also shows the pit dimensions (18" diameter and 22" deep), the drain pipe heights from the bottom of the pit (9" and 10"), and the water levels at which the pump turns on and off (11" and 6"). I believe the drain pipe on the right (9" above the pit base) has a much longer run than the other drain pipe.
As you can see in the diagram, the pump does not turn on until there is about 11" of water in the pit. Since the drain pipes are 9" and 10" above the pit base, the pump does not turn on until there is some standing water in the drain pipes.
Questions:
1. Do I need to adjust the pump float switch so that the pump turns on before the water level in the pit reaches the drain pipes? This way, the drain pipes won't have 1-2" of standing water in them before the pump turns on. In a slow season, it may take a few days for this much water to seep in the drain pipes. This means that the drain tiles below the basement floor could be quite wet before the sump pump even turns on. If I should reduce the turn on height, how would I do this? Options I can think of are to put a spacer at the top of the float slide bar, and also to replace the bricks at the bottom with something of a lower height.
2. Would the Zoeller M53 be a better fit than the M98? I am concerned that the M98 pump may be too powerful and so cycling too much. The water discharge is about 10 feet above the pump outlet. Since the M53 would take longer to empty out the pit, the incoming water from the drains may just keep that pump from turning off at all. The M98 is 1/2hp and pumps 3600 gph at 10 feet. The M53 is 1/3 hp and can pump 1900 gph at 10 feet. I do plan to finish the basement soon, and so don't want to have a situation where there is heavy rainfall, and the sump pump is not powerful enough to keep up with the heavy rain. Of course I don't want to see the pump cycling too much and burning up either.
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