ShinDiors
Electrical
- Dec 10, 2019
- 21
Newly found this forum and want to seek some insights on this water problem I've been trying to solve for our recently bought old house (built in 50s).
House we bought a year ago had this strange setup. In order to accommodate the addition of a 2-car garage and the sunroom above at the rear of original house, they extended/carved the driveway into the original backyard, and now the driveway is downward, with the end of it enclosed by the retaining walls. The only route that the run off water from the driveway, and from neighboring lot, backyard is a grated channel with a 4 inch PVC pipe buried under garage floor connected to a sump pit at the corner of the garage. Currently I have a liberty LE50 sewage pump in the pit, which goes 8400 gph at 5ft, but the discharge tube that connects to it is half inch smaller than the pump's 2 inch port. That tubing is partially buried into the cinder block wall then goes underneth/around the house to the street side drain. Pump is hooked up to the backup generator, so the power failure was not too much of a concern. Here is the problem:
The inlet 4inch PVC is at a rather low height of the pit, along with some foundation draintile inlets at similar height. 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, if raining more heavily, the pump runs for 10s 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). Water will then backed up at the grated channel and eventually enter the garage. I got some advise from drainage company that because of the water backed up inside the pit first, then backed up at the grated channel, it means that the bottle neck is the discharging capability rather than the inlet 4 inch pipe. What I need is to increase the discharge rate, so that the incoming water can flow freely (without backed up water in the pit blocking) into the pit.
I have got quite a few opinions, which are rather costly to me, from digging another pit at different location with another wiring and pump, to adding another pump in addition to my current setup and replace the entire discharging port with large pipes (including break through the cinder block wall to locate and replace the 1.5inch pipe goes out into the side backyard. A few concerns/questions I have in order to really pick a valid solution
1. From my description, do you feel that the problem is the discharging speed? I understand better solution is to reduce incoming water, for example, repair/waterproof the retaining wall to reduce he water from neighboring yard. My neighbor has already built a french drain system behind the retaining wall which helped a little, but I still see water pouring out from the retaining wall when it rains heavily. All my gutters were discharged through other pipes to the curb side and storm drain, and no visible overflow from the gutter (had guttergaurds) to the driveway run off.
2. How do I know if a pump is enough, for example, this 1/2 hp liberty pump has rate of 8400 GPH at 5ft, but the 1hp pump I got only has 7250 gph at 4ft. (curves from manufacturers attached), but requires much higher current/power than the 1/2 hp pump. The 1hp pump seems to have higher head according to the curves though. How do I compare this two pumps, if the max rate (speed at 0ft)matters, does it mean that my 1hp pump is not as strong as 1/2 pump i have right now (different brands)? I ask this because it looks like the failure prone portion of most pumps are the float switch, I was planning to use a Hydrocheck H6000 high-lo electric switch with the pump until I noticed that the switch is rated at 13.8A while this 1hp pump is 14.2A rated (3/4 hp ones would draw less than 12A which can be used with this switch). I attached the current Liberty pump 's curve and the new pump I just got (circled out the 1hp and 3/4 hp ones). If 3/4hp is what I need, then I would couple it with the electric switch no problem.
3. Another advise is to reduce the 90degree turns in the discharging pipes and use 2 inch pipes until it is connected to the 4inch gutter discharge pipe that is burried and eventually goes to the storm drain. My estimate is that there is not too much 1.5 inch tube after it goes out the wall and joint with the gutter pipe, would it help my situation if I replace the visble 1.5inch tubes with 2 inch pipe without breaking the wall? Again I understand it is ideal to replace everything 1.5inch before it's connected to the gutter drain.
4. If I swap a more powerful pump in the pit (say the ihp pump listed above), how do I adjust the float switch to avoid over-cycling, especially when it only rains light to moderately heavy) Should I let the pump turn on when water level is right below the inlet pipe since I notice that having water in the pit blocking the inlet seems to be reduce the inlet water speed quite a bit and cause water backup at the channel drain.
Sorry about such a lengthy post, I'm trying the provide as complete information as possible for your suggestions. Thanks a lot.
House we bought a year ago had this strange setup. In order to accommodate the addition of a 2-car garage and the sunroom above at the rear of original house, they extended/carved the driveway into the original backyard, and now the driveway is downward, with the end of it enclosed by the retaining walls. The only route that the run off water from the driveway, and from neighboring lot, backyard is a grated channel with a 4 inch PVC pipe buried under garage floor connected to a sump pit at the corner of the garage. Currently I have a liberty LE50 sewage pump in the pit, which goes 8400 gph at 5ft, but the discharge tube that connects to it is half inch smaller than the pump's 2 inch port. That tubing is partially buried into the cinder block wall then goes underneth/around the house to the street side drain. Pump is hooked up to the backup generator, so the power failure was not too much of a concern. Here is the problem:
The inlet 4inch PVC is at a rather low height of the pit, along with some foundation draintile inlets at similar height. 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, if raining more heavily, the pump runs for 10s 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). Water will then backed up at the grated channel and eventually enter the garage. I got some advise from drainage company that because of the water backed up inside the pit first, then backed up at the grated channel, it means that the bottle neck is the discharging capability rather than the inlet 4 inch pipe. What I need is to increase the discharge rate, so that the incoming water can flow freely (without backed up water in the pit blocking) into the pit.
I have got quite a few opinions, which are rather costly to me, from digging another pit at different location with another wiring and pump, to adding another pump in addition to my current setup and replace the entire discharging port with large pipes (including break through the cinder block wall to locate and replace the 1.5inch pipe goes out into the side backyard. A few concerns/questions I have in order to really pick a valid solution
1. From my description, do you feel that the problem is the discharging speed? I understand better solution is to reduce incoming water, for example, repair/waterproof the retaining wall to reduce he water from neighboring yard. My neighbor has already built a french drain system behind the retaining wall which helped a little, but I still see water pouring out from the retaining wall when it rains heavily. All my gutters were discharged through other pipes to the curb side and storm drain, and no visible overflow from the gutter (had guttergaurds) to the driveway run off.
2. How do I know if a pump is enough, for example, this 1/2 hp liberty pump has rate of 8400 GPH at 5ft, but the 1hp pump I got only has 7250 gph at 4ft. (curves from manufacturers attached), but requires much higher current/power than the 1/2 hp pump. The 1hp pump seems to have higher head according to the curves though. How do I compare this two pumps, if the max rate (speed at 0ft)matters, does it mean that my 1hp pump is not as strong as 1/2 pump i have right now (different brands)? I ask this because it looks like the failure prone portion of most pumps are the float switch, I was planning to use a Hydrocheck H6000 high-lo electric switch with the pump until I noticed that the switch is rated at 13.8A while this 1hp pump is 14.2A rated (3/4 hp ones would draw less than 12A which can be used with this switch). I attached the current Liberty pump 's curve and the new pump I just got (circled out the 1hp and 3/4 hp ones). If 3/4hp is what I need, then I would couple it with the electric switch no problem.
3. Another advise is to reduce the 90degree turns in the discharging pipes and use 2 inch pipes until it is connected to the 4inch gutter discharge pipe that is burried and eventually goes to the storm drain. My estimate is that there is not too much 1.5 inch tube after it goes out the wall and joint with the gutter pipe, would it help my situation if I replace the visble 1.5inch tubes with 2 inch pipe without breaking the wall? Again I understand it is ideal to replace everything 1.5inch before it's connected to the gutter drain.
4. If I swap a more powerful pump in the pit (say the ihp pump listed above), how do I adjust the float switch to avoid over-cycling, especially when it only rains light to moderately heavy) Should I let the pump turn on when water level is right below the inlet pipe since I notice that having water in the pit blocking the inlet seems to be reduce the inlet water speed quite a bit and cause water backup at the channel drain.
Sorry about such a lengthy post, I'm trying the provide as complete information as possible for your suggestions. Thanks a lot.
