ShinDiors
New Member
Have this single pump/pit to collect ground water from a downward driveway, backyard and neighboring yard inside this below grade sideload garage. arrows shows water direction. All gutters are drained through separate drain pipes goes directly into stormdrain curb side, not contributing to this sump, also not seeing overflow from the roof. Water just mainly come from the above lots (through the retainingwall) and the driveway. Not too much underground water either, so the main problem is the surface water. Pump inside is a Liberty LE50 sewage pump with 2" discharge port, but the piping is only 1.5".
50 gal sump pit, 20" inner diameter around the top but narrows down a little towards the bottom, 39" deep. The center of that PVC inlet pipe is about 22" above the tub bottom, so roughly at the center height (higher than I thought). The two black draintiles seem to be some kinda of foundation drain at the house's perimeter, I don't really see too much water from them. There is a smaller pvc seems to be the AC drain which is also minimum, the big PVC pipe is the 4inch tube that's buried under the garage concrete connecting the grated channel in front of garage. I think currently the concrete is grated to make this pvc pipe the lowest point. I can't tell the pump starting water level right now since it's only raining slightly, but judging from the sound (incoming water flowing down to hit the water inside the sump fading), I'd say it's set at about that inlet pipe level, around 20“-24”，it stops at maybe 2-3" where I can see the float sitting at the bottom out of the water.
The inlet 4inch pipe from the grated channel is roughly 23-24 ft, the height drop from entrance (at the channel) to exit (at the pit) is probably 20 inches or slightly less. I would see water pouring out fast when its raining heavily.
The discharging pipe: 38"(from pump up)-elbow-19"(horizontal)-elbow-7"(down to ground level inside crawl space)-33"-elbow-9"-elbow-87"(45degree up)-45degree elbow-11"-right angle elbow (where it exits the cinder block wall), there are two right angles elbow from the pump up then back down to ground level(I think can be eliminated?) to give space for the lid. Obviously a little too small for the pump.
Symptoms: when no rain, the pit is almost dry with not much underground water coming in, the pump is not running. When it rains the pump is cycling at reasonable frequency but only runs for about 10-15s each time then until the next cycle depending on the incoming water rate, if raining more heavily, the pump runs for 10-15s every 30s, until the incoming water start to back up in the pit and water level rises higher than the inlet pipe, that's when things start to go bad （happens once or twice a year). I would see the water inside sump pit slowly going up above or maintain. Water will then backed up at the grated channel and eventually enter the garage (normally I would see a 3/4 full tub while pump continuously run), and if it gets worse, it eventually would spilled out the tub.
My questions:
1. Is 10-15s on each cycle considered "short cycle"? What is the ideal on time and off time each cycle?
2. What is the normal float switch on water level? My gut feeling is it should not be far away from the inlet pipe level other wise water would backed up in the inlet pipe (basically the pipe itself become water-full)
3.Are these symptoms indicating an undersized sump pit (est maybe less than 20gal volume to pump out for each 10-15s cycle) or is it the undersized discharging pipe (1.5" pipe) or both? I want to start by upsizing the 1.5" pipe to 3" all the way until it taps in the 4" gutter drain underground in my backyard. But if the sump size (usable volume) is the problem, improving discharging may cause my pump to cycle on even shorter time correct?
Any thoughts? Thanks in advance.
50 gal sump pit, 20" inner diameter around the top but narrows down a little towards the bottom, 39" deep. The center of that PVC inlet pipe is about 22" above the tub bottom, so roughly at the center height (higher than I thought). The two black draintiles seem to be some kinda of foundation drain at the house's perimeter, I don't really see too much water from them. There is a smaller pvc seems to be the AC drain which is also minimum, the big PVC pipe is the 4inch tube that's buried under the garage concrete connecting the grated channel in front of garage. I think currently the concrete is grated to make this pvc pipe the lowest point. I can't tell the pump starting water level right now since it's only raining slightly, but judging from the sound (incoming water flowing down to hit the water inside the sump fading), I'd say it's set at about that inlet pipe level, around 20“-24”，it stops at maybe 2-3" where I can see the float sitting at the bottom out of the water.
The inlet 4inch pipe from the grated channel is roughly 23-24 ft, the height drop from entrance (at the channel) to exit (at the pit) is probably 20 inches or slightly less. I would see water pouring out fast when its raining heavily.
The discharging pipe: 38"(from pump up)-elbow-19"(horizontal)-elbow-7"(down to ground level inside crawl space)-33"-elbow-9"-elbow-87"(45degree up)-45degree elbow-11"-right angle elbow (where it exits the cinder block wall), there are two right angles elbow from the pump up then back down to ground level(I think can be eliminated?) to give space for the lid. Obviously a little too small for the pump.
Symptoms: when no rain, the pit is almost dry with not much underground water coming in, the pump is not running. When it rains the pump is cycling at reasonable frequency but only runs for about 10-15s each time then until the next cycle depending on the incoming water rate, if raining more heavily, the pump runs for 10-15s every 30s, until the incoming water start to back up in the pit and water level rises higher than the inlet pipe, that's when things start to go bad （happens once or twice a year). I would see the water inside sump pit slowly going up above or maintain. Water will then backed up at the grated channel and eventually enter the garage (normally I would see a 3/4 full tub while pump continuously run), and if it gets worse, it eventually would spilled out the tub.
My questions:
1. Is 10-15s on each cycle considered "short cycle"? What is the ideal on time and off time each cycle?
2. What is the normal float switch on water level? My gut feeling is it should not be far away from the inlet pipe level other wise water would backed up in the inlet pipe (basically the pipe itself become water-full)
3.Are these symptoms indicating an undersized sump pit (est maybe less than 20gal volume to pump out for each 10-15s cycle) or is it the undersized discharging pipe (1.5" pipe) or both? I want to start by upsizing the 1.5" pipe to 3" all the way until it taps in the 4" gutter drain underground in my backyard. But if the sump size (usable volume) is the problem, improving discharging may cause my pump to cycle on even shorter time correct?
Any thoughts? Thanks in advance.
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