septic pump and control circuits - best practices and code

[Rossn]

Can anyone clarify requirements and best practices around residential septic circuits?

The current dwelling septic tank has one dedicated circuit for pump and controls/alarm. The local septic company indicated two circuits are customary.

Here is what I've come to understand so far, please feel free to correct. NEC references always helpful.

• Two circuits 1) 12-2 for pump 2) 14-2 or better for control and alarm
• NEC 2017 210.8(A) seems to indicate these outdoor circuits would require GFI, while many (Electricians included) say they will not GFI a septic or sump pump for catostropic failure reasons. Some AHJs may allow this.
• Unclear if either or both circuits should also have some dwelling lights on them, so as to indicate if there is a breaker or GFI (if GFI'd at panel) open, but I'm inclined to consider at least the control/alarm circuit on a lighting circuit, if that is reasonable to do

Thanks for sharing your direct experience here

 

[WorthFlorida]

I'm not a electrician but I do have an electrical degree. There are GFCI's with an audible alarm but they are with receptacles. The bottom line is what the local jurisdictions wants. You really need to call your local jurisdiction permit office or engineering dept. to ask this question.

A new install with permit, the inspector may call for GFCI. The NEC section mostly states "receptacles". The septic system should be all direct wire without any receptacles unless it is down stream from the controller where a GFCI would be required and it would not shut down the septic system should it trip. Each circuit should have its own cutout switch within easy access from the pumps and controllers.

False tripping with GFCI has become a lesser occurrence. Each GFCI has a micro chip that seems to be more reliable than ever. A few years back, I added two circuits for receptacles both outdoor and garage garage receptacles. The garage included a refrigerator where I keep 1/2 of the frozen foods in. I live in Florida, the lightning capital of the world and in 33 years in Florida, I never had a GFCI falsely trip. The only time was when wind driven rain entered the receptacle. My current home has three GFCI circuits for the outdoors.

With a septic system, worse case with a false trip would be a little backup since flushing toilets would be gurgling and poor drainage else where. There are alarms via float switches that can be installed within the septic system. There are GFCI without receptacles that are used in commercial kitchens where receptacles can be behind appliances or on a pedestal a few inches off the floor.

NEC has been increasing GFCI to be just about everywhere in a home to reduce electrocutions. A few years back new sections were added for electric vehicles charger installations.

https://www.eaton.com/us/en-us/company/news-insights/for-safetys-sake-blog/NEC-2020-increases-GFCI-protection.html

 

[Sponsor]

 

[Rossn]

I'm not a electrician but I do have an electrical degree. There are GFCI's with an audible alarm but they are with receptacles. The bottom line is what the local jurisdictions wants. You really need to call your local jurisdiction permit office or engineering dept. to ask this question.

A new install with permit, the inspector may call for GFCI. The NEC section mostly states "receptacles". The septic system should be all direct wire without any receptacles unless it is down stream from the controller where a GFCI would be required and it would not shut down the septic system should it trip. Each circuit should have its own cutout switch within easy access from the pumps and controllers.

False tripping with GFCI has become a lesser occurrence. Each GFCI has a micro chip that seems to be more reliable than ever. A few years back, I added two circuits for receptacles both outdoor and garage garage receptacles. The garage included a refrigerator where I keep 1/2 of the frozen foods in. I live in Florida, the lightning capital of the world and in 33 years in Florida, I never had a GFCI falsely trip. The only time was when wind driven rain entered the receptacle. My current home has three GFCI circuits for the outdoors.

With a septic system, worse case with a false trip would be a little backup since flushing toilets would be gurgling and poor drainage else where. There are alarms via float switches that can be installed within the septic system. There are GFCI without receptacles that are used in commercial kitchens where receptacles can be behind appliances or on a pedestal a few inches off the floor.

NEC has been increasing GFCI to be just about everywhere in a home to reduce electrocutions. A few years back new sections were added for electric vehicles charger installations.

https://www.eaton.com/us/en-us/company/news-insights/for-safetys-sake-blog/NEC-2020-increases-GFCI-protection.html

Thanks for weighing in. I can ask the inspector, but trying to make sure I've done my due diligence and minimize how many times I'm asking for him to clarify AHJ questions.

I opened up everything today to figure how it is put together, and at that point, my gut said I should GFI the circuit and figure out how to notify if there is a disconnect, both by tying it into some lighting and some technology. Basically, there is a pedestal and jbox (with controls and alarm) that the power comes into (via UF laying on the ground... ugh), and from the control board, they put a female end of a plug on, then plugged in a male end of a plug, which is then connected to individual conductors that enter conduit that goes to the septic 3rd tank. In the wet and humid tank it has a weather sealed box near the top of that tank, and then some water tight connectors on the box, with leads to the pump and various floats. My assumption is the pump was plug and cord style, and they cut the cord end and ran it through one of those water tight connectors made for round cords. Similar for the floats. Inside the jbox was standing water on one end and the wire nuts that are made for damp environments.

Seeing that, I think I should probably GFI at the breaker, then consider putting some lighting on the circuit for notification, but that would also mean adding AFCI. I haven't had a chance to look at options in detail, but there are definitely some notification services (and likely others that can plug into home automation) such as https://gfinotify.com/.

Now, on black water backup.... it would be a big deal if it happened. The point of exit would be floor drains, and that would lead to getting under a subfloor assembly on top of the slab, and... well, we're $5-30k in at that point. So, have to be absolutely sure that can't happen.

 

[Reach4]

240 volts? That might make a difference.

I would not want a GFCI, myself.

 

[Rossn]

240 volts? That might make a difference.

I would not want a GFCI, myself.

It's 120.

That's what I was thinking. Then I saw 1/4" water in the junction box, and I thought... maybe it would be a good idea.

But blackwater backup... that's about as bad as it gets.

 

[Reach4]

But blackwater backup... that's about as bad as it gets.

Worse than your blackwater backing up would be somebody else's blackwater backing up into your basement/house. That can happen with city sewers.

 

[Rossn]

Worse than your blackwater backing up would be somebody else's blackwater backing up into your basement/house. That can happen with city sewers.

It all stinks. Growing up, my parents had a home with a sunken tub, and on a unique property. Based on the city's pumping habits, during rain storms, the tub would fill with black water. Amazingly, never went over, but the water authority would never modify their system to prevent it. I guess in a place with no basements, they feel the flood level to grade is acceptable.

 

[Rossn]

For posterity,

I spoke with a guy who is a non-practicing local master electrician. His take was that there isn't a practical hazard to not having a GFI, unless you have the septic pit open, and recommended foregoing the GFCI if allowed by the county + ensuring there is a proper readily-accessibly disconnect in-sight of the septic tank (which there is not today). I spoke with my inspector, and locally they do not enforce GFCI on Septic pump circuits.

So, I will
- Install a disconnect in sight of the septic tank
- Pump: Run 12/2 on dedicated circuit std breaker, NM inside, UF or THHN/THWN outside in conduit
- Controls/Alarm: Tap into an adjacent interior 15A lighting circuit running on Dual-Function breaker and run 14/2 to the control. NM inside, UF or THHN/THWN outside in conduit

 

[Fitter30]

Standard gfci TRIPS AT 5 Ma which a motor in a wet damp condition might have nuisance trips. They do make a gfci breaker that trips at 30 Ma that should stop nuisance trips would have to check with the electrical inspector. Replace plastic box and fittings then seal with urethane or polyurethane caulk.

 

[Rossn]

Standard gfci TRIPS AT 5 Ma which a motor in a wet damp condition might have nuisance trips. They do make a gfci breaker that trips at 30 Ma that should stop nuisance trips would have to check with the electrical inspector. Replace plastic box and fittings then seal with urethane or polyurethane caulk.

Thanks. Since the inspector said we are OK without GFI, and a local electrician recommended only having a disconnect in sight, I will probably go that way. However it's good to know about that alternate breaker with the higher threshold. I see Homeline has them in the HOM-EPD category. Thanks for pointing that out.

May I ask why you suggested replacing the plastic box?

 

[Fitter30]

Thanks. Since the inspector said we are OK without GFI, and a local electrician recommended only having a disconnect in sight, I will probably go that way. However it's good to know about that alternate breaker with the higher threshold. I see Homeline has them in the HOM-EPD category. Thanks for pointing that out.

May I ask why you suggested replacing the plastic box?

Wrote that there was a 1/4" of water in bottom of box. New box and cover with new screws have a clean surface for caulking to stick to. The wires in the conduct might what to caulk the wires in the pipe. Electricians normally don't use pvc primer or if steel don't use a thread sealant at threaded joints.

 

[Rossn]

Wrote that there was a 1/4" of water in bottom of box. New box and cover with new screws have a clean surface for caulking to stick to. The wires in the conduct might what to caulk the wires in the pipe. Electricians normally don't use pvc primer or if steel don't use a thread sealant at threaded joints.

Ok, thanks. Maybe just cleaning and putting a new gasket and connectors on would address the issue? I fear cutting out the box turning into a much bigger project than it appears on the surface, depending on the condition of the conduit that is under ground. My guess is the connectors might be the ones that might be letting the air in.

 

[Reach4]

Standard gfci TRIPS AT 5 Ma which a motor in a wet damp condition might have nuisance trips. They do make a gfci breaker that trips at 30 Ma that should stop nuisance trips would have to check with the electrical inspector. Replace plastic box and fittings then seal with urethane or polyurethane caulk.

I would consider using duct seal where the wires come in via the conduit. Really push it in there. Keeps water vapor out, I think. Also keeps bugs out, at least I hope.

It may be that the urethane would be more resistant to pressure, but it would not be removable. Maybe removable is not important here.

 

[Rossn]

I would consider using duct seal where the wires come in via the conduit. Really push it in there. Keeps water vapor out, I think. Also keeps bugs out, at least I hope.

It may be that the urethane would be more resistant to pressure, but it would not be removable. Maybe removable is not important here.

That is a good idea, Reach!

You and Fitter had me thinking about this a little more about this. I know... electrical in a plumbing forum and this is the right approach for the crowd... I'm going to put on more of electrician hat in the moment It is possible the moisture is not coming in through the box or connector seals, at least exclusively. NEC 300.5 requires conductors in underground conduit be wet rated, due to condensation that occurs. My guess is that at least some of that water is coming from the condensation (which would be increased if there is leakage between the septic pit and conduit, and the conduit does slope down to the septic). I think that regardless of what is done, there's going to be some moisture in that box.

I think of NEMA electrical equipment rated for outdoors, and I believe they all have drain holes. I'm guessing that's not the right thing to do here, but there is likely a better solution and will ask an electrician I know. Some standing water in that box is not something I was happy to see. Last thing I want is that box filling up with water to the conductors, potentially creating a hazardous situation and/or the septic pump going offline.