Ok, I have done some testing but I have some big questions here. I hope this post isnt too long. I apologize ahead of time if it is.
#1
I tested the float switches. The pump's on/off came on a bit late, only about an inch from the bottom of the intake. And in doing so, got caught under the "nub" on the front intake (left side). But as the water rose, it floated to the side and worked properly. Still, I wasnt happy with that. The alarm, got caught under the "nub" on the right side and didnt go off. -- which is what I was afraid of.
So, I moved both switches and shortened the tethers. They seem to work ok now. The on/off makes before the float touches the intake nub (I hope someone can tell me what that piece is called so I dont have to keep using the word "nub"). The alarm sits on top of the pump and comes on about an inch below the intake level.
This is the best placement I can think of for these. Do you think these switches will be reliable based on what you can see or is there a better way to set them? The tether on each is only about 3.5". Actually, the tether on the alarm may be a bit less than that now.
#2
The manual says to have the check valve horizontal if used for solids. So, I put it horizontal. In order to do that, I needed a couple of bends. I tried to use all 45s so they are not sharp bends. It seems to work just fine.
But the manual also says to have on the waste line: a union, a check valve, and a gate/ball valve. In that order. I am questioning this.
UNION
I dont see the value in a union. A union lets you easily disconnect things. In this case, with the union glued to the waste pipe, even undoing the union wont allow you to take the cover off for maintenance. The bottom half of the union would prevent the cover from sliding off the waste pipe--which is threaded into the pump. So, what would the value of a union be? It seems that a compression coupling or a fernco would make more sense. These can be removed completely and easily so that the cover could slide right off. A union on the vent would make sense since the vent only goes into the cover a couple of inches and could easily be removed with the cover once the union is undone.
CHECK VALVE
No problem with this.
GATE/BALL VALVE
I went with the ball valve because I couldnt find a PVC gate valve in 2". But again, I dont see the value. The valve is for isolating the pump for maintenance (I think). But there is a check valve. Nothing should come back any further than that. And if the check valve was stuck open or not working in some way, there is only the small amount of pipe from the valve to the main waste line. I cant imagine any residential situation has much distance between the two. And since the waste must connect to the main from above, there is no danger of anything else coming down into the basin. So what is the real value of the valve?
#3
The pump comes on when the water is about 14 inches deep (bottom of the intake is 16"). It shuts off at about 7 inches. At 18 inches diameter that means it is pumping about 1 cubic foot of water--or about 8 gallons.
That doesnt seem very efficient considering it is a 30 gallon basin. I plan on putting my washing machine into this basin as well as the downstairs bathroom. Will this be pumping too often? If my washing machine uses 20 gallons (just a guess based on what I have read), the pump could turn on 3 times per wash cycle.
