Septic pump and floats

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Esthy

Senior Member
Well, since I moved here I have more question than a five year old. I read Dennis Alwon answers to a septic floats problems in another forum and I think maybe he can answer my questions, I wrote the following in the plumber forum but with not results, here is:

"I was visiting people in the country and I hear the alarm for the septic pump. My friend opened the area and with a rake push down two of the floats several times until the alarm stop. I asked what was going on, and he explained that two months ago a plumber installed, after the septic was pumped out, a new pump, but since that, the alarm goes on and on and my friend keep pushing the floats down, sometimes every two hours and sometimes it last good for a week. I really I am not familiar with this situation as never I worked with septic tanks/pumps"

Also, there is a manhole underground box next to the septic and a sleeve where the 3 (4?) cables going to the pump floats and because there are no receptacles there the plumber in his presence cut the plugs and hardwired the floats to the existing wires in the manhole, he didn?t do any alteration (besides cutting the plugs). I saw standard wires nut (this is a wet area) and I asked and he answer that because the plumber did it in a holiday and in the country, he had no recourses there. From that manhole there is another conduit that goes to the underside of this manufacture house to the alarm and whoa! That area is a ?Spaghetti Country? etc., etc. Also, my friend mentioned that maybe the floats are not in the right position (?)

Of course, as I mentioned in my previous posts, I am new with this here and I still learning ... Any help?
 

StarCat

Industrial Engineering Tech
Location
Moab, UT USA
Occupation
Imdustrial Engineering Technician - HVACR Electrical and Mechanical Systems
Float Switch setup

Float Switch setup

On a typical duplex pump system which is what you definitely want so you have redundancy, there are 4 float switches used ALL of them are " close on rise " type.
They do have to be set to the correct level in sequence vertically.
Bottom float is failsafe for pump starter
Next float is lead pump
Next float is lag pump, this is noted as alternating setup crosswired so both pumps can run under increased fluid load
Last float is your alarm which should NEVER come on if the system is setup and maintained correctly.
A simplex panel would be similar without the one extra control float.
Usually the effluent is moved to a septic tank then the tank is ported to a drainfield as usual.
 

ActionDave

Chief Moderator
Staff member
Location
Durango, CO, 10 h 20 min from the winged horses.
Occupation
Licensed Electrician
Esthy, what happens after the floats get pushed on with a rake? Does the pump go through a cycle with no rake involved?

Sounds like a problem with the floats. Either the floats are bad and need replaced or are hooked up in the wrong order.

The lowest float is the Off float, middle float is On float, top float is Alarm or lag float depending on if there is one pump or two.

The wet well should fill up till the middle float switch closes and starts the pump, it will pump down till lowest float drops and stops the pump. One of them is sticking or is miswired or the wrong floats were installed.
 

Esthy

Senior Member
He pushed, really banging them down, 2 of the floats that were "floating" at water level and the alarm stop bipping and the pump started, but he said that it can work properly for two hours and sometimes for a week. I am really interested in doing this type of repairs, but I don't find diagrams for. By the way, it is a 3 floats there and I think you are right,it looks they are at the same level. Is this type of work guided by NEC?
 

Dennis Alwon

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Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
Sounds like a bad float or the floats are tangled causing the on float to not work. Sometime it can free itself and sometimes it gets caught again. It could be either of those. Since the "ON" float should be lower than the alarm when it is extended my guess is it may not be or its a bad float

There are usually 3 floats

The first is near the bottom- not sure how far up- and that is the "off" float.

The second one may be about half way up and that is the "on" float

If the "on" float gets jammed sewage will fill until the alarm is activated. Using the rake to push them around obviously disentangles them or somehow helps unstick the switch.

If I had to guess I would bet the plumber did not install them correctly.

Another possibility I just thought of was he has the top float the as the "on" switch and the alarm float in the middle. Those tank should not fill up that easily (20 min). They should be able to go for a day or so but if he is going a week then I suppose this is not a realistic reason. It is hard to say because it could also be a combination of things.

In our area the septic guys install the pumps and floats- we wire them
 

Esthy

Senior Member
I found this in the Internet and I think this is what he has, but I saw, regretted no taking pictures but I will do, 2 floats at the same water level and he has to bang the 2 togheter to stop the alarm and star the pump
 

Esthy

Senior Member
Dennis, Of course I believe you but I don't believev my mind. I asked today on the phone (he's far away) about the situation and he said it did again today. He said that 2 lines, one 15 amps and one 20 amps go to the manhole and there are all the connections, but I am thinking: shouldn't be only one line for the pump as the 3 floats "act as a 4 ways switches"? Or maybe the alarm is a separated line? Where can I find a diagram for thus type of 3 floats pump?
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
There are many system out there but there should only be the cords from the floats and pumps that go into the tank. He may have an old system where the boxes were installed in the well.

Today there is usually a manufacturers control box that is mounted outside the tank and the rubber cords get sleeved in conduit into the box. Here you would have to follow the diagram of which switch went where.

The old system just needed an outlet and the pump cord cap had a receptacle on the back side- piggyback that would allow the "on" float to energize the pump thru that cordcap. In that system we would plug an alarm box in at the house and run a control wire to the alarm float. I believe the off was the same float as the on float... when the water rises the float would turn sideways and activate the switch and when the float straightened out as the water receded the pump would shut off.
 

Esthy

Senior Member
But thinking now, shouldn't the alarm circuit be a dedicated one? Not wire in the pump circuit ...
 

ActionDave

Chief Moderator
Staff member
Location
Durango, CO, 10 h 20 min from the winged horses.
Occupation
Licensed Electrician
Dennis, Of course I believe you but I don't believev my mind. I asked today on the phone (he's far away) about the situation and he said it did again today. He said that 2 lines, one 15 amps and one 20 amps go to the manhole and there are all the connections, but I am thinking: shouldn't be only one line for the pump as the 3 floats "act as a 4 ways switches"? Or maybe the alarm is a separated line? Where can I find a diagram for thus type of 3 floats pump?
Each house can be a little different but the principles are the same.... you need an alarm float, a start float, and a stop float and a pump. Better set ups have a control panel.

Your friend has some bad floats, miswired floats, or both. A bad pump is possible, but you said that was replaced so I'm leaving that one off the list for now.
 

Esthy

Senior Member
Thanks, I will try to go there next weekend to "practice", do you know where I can find a diagram?
 

Barbqranch

Senior Member
Location
Arcata, CA
Occupation
Plant maintenance electrician Semi-retired
There isn't always 3 floats on a single pump system w/ alarm. On mine, there is one float that has enough hysteresis (set by the length of the wire from the support to the float) to start it on rise and when enough is pumped, it stops. Eliminates the need for a separate pump controller. Second float is alarm, as stated earlier, on a separate circuit. You don't want the system to flood just because pump kicked out the breaker and then the alarm wouldn't work. To me it sounds like the 2 floats may be too closely mounted, such that sometimes the alarm comes on before the other float starts the pump. A test of this would be to run 50 gallons or so of water when the alarm is on, to see if a little extra depth would trigger the pump.
 

JRW 70

Senior Member
Location
Eastern Central Missouri
Occupation
Testing and Engineer
Check Valve ?

Check Valve ?

If this wet well is re-filling in 20 min., and then can go
for a week. Leaking check valves have been a notorious
problem at one of our plants when the high water pumps
try to push the river back out (the discharge water normally
passes through the check valve with no pumping involved)

Just an abstract thought. Check all bases so to speak.

JR
 

Esthy

Senior Member
Whoa JRW 70, according to my friend this pump doesn't have a check valve because it is residential (???) I think the plumber made a mistake here. So now, no check valve, wrong position of the floats, maybe some wrong wiring and ... of course maybe this is the problem.
 

Jon456

Senior Member
Location
Colorado
Note that there are two types of floats available: Normally Open (close on rise) and Normally Closed (open on rise). It's possible the plumber installed the wrong type of float.

Also, on Duplex systems it's common to only have three floats where the lag and alarm terminals are jumpered together.
 
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