Re-do septic system wiring

[Uncle Ben]

Hey everyone, I've got an electrical mess inside my aerobic septic system that I need to re-wire. I wanted to get any tips that you may have to offer.

The wiring inside the 3rd tank of my septic system (where the water pump is located) has a short somewhere, and the wiring is getting hot and smoking, and I even saw a spark/pop once or twice right before the breaker tripped.

The system has worked ok for the most part over the last 4 years since I bought the house, but the wiring looks very poorly done. What started happening is that my breaker for the water pump would be tripped, and sometimes I can flip it back on and it will work fine for a period of time, and then trip again at some point. When opening up the lid I could see that the wiring inside the 3rd tank of my septic system (where the water pump is located) has a short somewhere, and the wiring is getting hot and sometimes (not always) smoking when the sprinkler pump is running, and I even saw a spark/pop once or twice right before the breaker tripped.

I thought maybe I could just re-do all the connections to fix it, so I stripped back the wires and re-connected every single connection that is in the top of that tank, filled all the wire nut connections with dielectric grease, then wrapped thoroughly w/ electrical tape, but the problem did not go away or even improve at all, so it seems I will need to remove all the existing wiring and start over completely. You can see on the left side of the attached photo that there is conduit coming into the top of the tank. There are two separate conduit pipes, each with one wiring coming out.

This tank has a water pump, a lower float (to trigger the water pump function), and an upper float (which triggers the tank overflow alarm).

I could simply try to duplicate the wiring that is already there, but start from scratch with all new wire, but it is quite a mess and would probably be more confusing to try to "copy" it, rather than follow a guide or wiring diagram of some kind.

I do all my own work around the house, and can't afford to hire this out anyway, so I've got to figure out how to fix this, so I am open to any tips, advice or even articles/videos that you could point me to. Thanks!!

 

[Innovate1]

It could be the pump is going bad and drawing more current than it should. I think I would start by drawing out the wiring and all the connections. Then can you supply power directly to the pump and measure the current to see if it is working properly? Where did you see the spark? I would check the connection and insulation there as a start.

 

[wyliesdiesels]

oh what a ****** mess

is that UF-b? doubt that is listed for a caustic environment like a septic tank.

no telling what someone may have jury rigged. best to probably rewire the whole thing. can you draw out a schematic of how everything is connected?

 

[Chuckster in NJ]

Try to borrow (or buy) a megger and check the motors and wiring.….. Google search on how to do this.

 

[mm08822]

I even see SJ cord. Can't tell if that is eventually submerged.

Look up septic pumps and check the cut sheets to see what is the common wiring materials as a start.

 

[Uncle Ben]

Here are a couple more photos to show the inside of outdoor breaker box, as well as a junction box that is next to it. I included a wider shot so you can get an idea of which wiring goes between the two boxes, and which wiring goes down into the ground.

The box on the far left and far right are not part of the septic system.

I will look into what type of wiring (and connectors) should be used. The wiring "should" never get submerged, but if the breaker trips or the pump goes out, the tank could slowly fill to the top, so it is possible.

 

[Chuckster in NJ]

I hate to break the news to you BUT………. That mess is a real **** show (pardon the pun) and needs to be TOTALLY re wired the proper way and if you don't have the skills I highly suggest calling a pro to do it the right way with the proper materials.


BTW! Once done properly you will enjoy years of use without any problems and "IF" you have any problems it will be easy to troubleshoot.

 

[BillK]

I think the first thing you need to do is determine exactly what is failing. If you actually saw a spark then you should have found some burnt wires when you redid all of the connectors. If all of the connections looked normal then there is probably nothing wrong with the actual wiring. There is no sense to replacing all of the wiring if the problem is the pump motor, float switch or something else.

 

[reader2580]

I wouldn’t want to plug a new pump into that mess.

I have a pump in my septic tank. If my memory is correct the cord for the pump connects into a junction box above ground. The wiring comes up through a plastic post. It is about the only wiring that was done right when I bought the house.

 

[Chuckster in NJ]

Here are TWO methods for wiring a septic tank pump and alarm.……. Again, use the proper materials and methods.

 

[reader2580]

My septic system is wired very much like the first picture. The electrical box is not as big as that though. It is a 4”x4” box mounted on a hollow vinyl fence post. The wires come up inside the fence post.

I hit the thing several times with my riding mower. At one point a wire came loose inside from the hits. I have come up with a way to mow where I won’t hit the box anymore.

 

[walta]

Generally, I thought this type of system was required to have an alarm circuit separate from the pump circuit that would make it clear the system had a fault and required service. Making for a complex circuit that will not be easily understood at first glance.

I understand money is tight but playing amateur electrician in a wet location is always a risky game add the unpleasantness of this location only make the situation worse.

Since the breaker is tripping something is drawing too much current. A bad connection type fault would most likely not trip the breaker. It seems unlikely the fault is in the wires but if the fault is in the wires you would expect to find missing insulation that is allowing two wires to touch each other and I don’t see anything like that.

Since to sometimes works for a little while, my guess is something besides #1 & 2 got in the tank and then into the pump wrapping itself around the shaft. This makes the pump work harder than it should drawing more current and tripping the breaker. I would start by pulling the pump and testing it.

The “flushable wipes” that were popular a few years ago come to mind.

Walta

 

[dave*99]

The “flushable wipes” that were popular a few years ago come to mind.

Now the wipes have gender. Not that there is anything wrong with that.

 

[Uncle Ben]

Generally, I thought this type of system was required to have an alarm circuit separate from the pump circuit that would make it clear the system had a fault and required service. Making for a complex circuit that will not be easily understood at first glance.

I understand money is tight but playing amateur electrician in a wet location is always a risky game add the unpleasantness of this location only make the situation worse.

Since the breaker is tripping something is drawing too much current. A bad connection type fault would most likely not trip the breaker. It seems unlikely the fault is in the wires but if the fault is in the wires you would expect to find missing insulation that is allowing two wires to touch each other and I don’t see anything like that.

Since to sometimes works for a little while, my guess is something besides #1 & 2 got in the tank and then into the pump wrapping itself around the shaft. This makes the pump work harder than it should drawing more current and tripping the breaker. I would start by pulling the pump and testing it.

The “flushable wipes” that were popular a few years ago come to mind.

Walta

Thanks for the input.
I did find some wire that had some charring, and some where the insulation had melted away a little bit, but I didn't find anywhere that two un-insulated wires were touching, so I'm not sure how the pop/spark would have occurred, but some of the wires in this tank are a two-wire cable, so perhaps the insulation that is between two wires on the same cable could have melted and allowed the two wires to arc.

Either way, to your point, there must be a reason that the wires would get hot enough to smoke and melt away some insulation, and then trip the breaker, so I guess that means there is a motor issue of some kind, aside from any wiring issues, which someone else mentioned earlier in this thread as well. So I'd better investigate the pump fully before I re-wire.

I'll need to learn how to pull up the pump for inspection, and also how to test the pump itself for excess current draw, etc.

 

[reader2580]

My septic system has an alarm that is a separate two wire cable like thermostat wire going to the tank. The alarm is inside the house with a plug in transformer and a 9 volt battery as backup.

It works because a wire nut came loose from hitting the box with mower and the alarm sounded when the tank got too full.

 

[dave*99]

and also how to test the pump itself for excess current draw, etc.

Get a clamp on ammeter. At both ends of your system there are places where you can clamp around single conductors and get current readings. Please be careful and don't work alone.

 

[Chuckster in NJ]

Thanks for the input.

I'll need to learn how to pull up the pump for inspection, and also how to test the pump itself for excess current draw, etc.

Don’t pull the pump yet………. Keep the pump in place to check the current draw.

 

[wyliesdiesels]

I did find some wire that had some charring, and some where the insulation had melted away a little bit, but I didn't find anywhere that two un-insulated wires were touching, so I'm not sure how the pop/spark would have occurred, but some of the wires in this tank are a two-wire cable, so perhaps the insulation that is between two wires on the same cable could have melted and allowed the two wires to arc.

the charring melting and arcing can be from a bad splice that has poor contact creating a hi-resistant connection. it doesnt have to be a line to line fault

 

[walta]

the charring melting and arcing can be from a bad splice that has poor contact creating a hi-resistant connection. it doesnt have to be a line to line fault

All true but that kind of fault also will not trip the breaker repeatedly.

Walta

 

[Uncle Ben]

I opened up the outside panel box again and put a clamp amp meter around the hot wire coming out of the bottom of the breaker for the pump. As soon as I flip the breaker on, it shows a higher number (possibly around 38 Amps) for a split second that is too fast for me to read, but then sits at 12.5 Amps and lowers to 12.3 Amps after a minute or so. I assume that is the rush current that only happens when the pump is first activated.

I saw the meter go up to about 15 Amps for a split second right at the moment that the breaker tripped, and I'm assuming that the meter is not responding fast enough to keep up with the amps when it suddenly spikes enough to trip the 20A breaker. I looked at my meter's specs, and the data rate is only 3 times per second, so it could be that 15 amps was the the last reading it was able to pick up before the breaker tripped.

If I flip the breaker back on, the pump will activate again, usually for 1 or 2 minutes before the breaker trips again, but I have had instances where it would trip within a few seconds of turning the breaker back on, in which case I will leave it alone for a while before turning it back on or trying to test it again.

 

[dave*99]

It would be helpful to know the spec on the pump for current draw.

 

[Uncle Ben]

Yeah, I think I'll need to pull up the pump (never done that before) to see what it is, at which time I'll also be able to inspect it and see if we have a clog issue or anything else going on.

 

[wyliesdiesels]

I opened up the outside panel box again and put a clamp amp meter around the hot wire coming out of the bottom of the breaker for the pump. As soon as I flip the breaker on, it shows a higher number (possibly around 38 Amps) for a split second that is too fast for me to read, but then sits at 12.5 Amps and lowers to 12.3 Amps after a minute or so. I assume that is the rush current that only happens when the pump is first activated.

what model clamp meter do you have? only certain models have the correct circuitry to correctly read in-rush current. in-rush current is typically during the first 200ms or so of startup

 

[Uncle Ben]

It's a fairly cheap meter that I got off Amazon that I typically have in my electrical bag...I don't recall the brand at the moment, but I do have another much better meter (UEi) that I can re-test with. That one stays in one of our vehicles.

But maybe the in-rush current isn't really the issue though, since it does not trip the breaker immediately...it usually runs for at least a minute (sometimes much longer) before the breaker trips, so I suppose I just need to see what the Amp reading is hitting right when the breaker trips, and that seems to be what my cheaper meter is not catching.

 

[Chuckster in NJ]

Fuggabout the mili second inrush current because In my experience a 3/4 HP septic pump in good condition usually draws 9-10 amps so "IF" you are drawing over that (assuming OP has a 3/4 HP pump) my guess would be a failing cord or there is water inside the windings or connection box.…….. I would pull then replace the pump with a new one (the same size) along with properly rewiring everything using the proper materials.