Sump Pump Installation for Water Treatment

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tbakelis

Senior Member
Hello All,

I've been a mainly residential electrician for about 9 years now. Obviously learning a bit as I go by doing new jobs. I'm bidding a "quasi" residence up in the boonies that is requiring a sump pump for it's waste water treatment. I've done one of these before for a candy store that was located indoors. This one is located outside about 10 feet away from the building. It has 2 - 1 hp pumps rated at 240 volt (12.3 amps each). The alarm panel for this is going to be located in a utility room in the building roughly 70 feet away.

Question #1: How is the connection to this unit made typically? Will the pumps come with factory installed cords long enough to plug in to a receptacle on the building 10 feet away? Are they hard wired into a disconnect on the building 10 feet away? Do I need to install a 4x4 near the pit that will have the disconnect for these pumps and then conduit over to the building?

Question #2: Do I run 2 separate 20 Amp / 240 Volt circuits to the pumps? Or do I run to a small load center (40 Amps) near the pit and then branch off from there?

Question #3: Since the alarm panel is going to be approximately 70 feet from the actually pit, is there control wiring that runs the length?

Any advice is appreciated.

I really want to get this job but this is the only item of the bid I am having questions about.

Thanks and Happy Holidays!

Ted
 

John120/240

Senior Member
Location
Olathe, Kansas
Hello All,

I've been a mainly residential electrician for about 9 years now. Obviously learning a bit as I go by doing new jobs. I'm bidding a "quasi" residence up in the boonies that is requiring a sump pump for it's waste water treatment. I've done one of these before for a candy store that was located indoors. This one is located outside about 10 feet away from the building. It has 2 - 1 hp pumps rated at 240 volt (12.3 amps each). The alarm panel for this is going to be located in a utility room in the building roughly 70 feet away.

Question #1: How is the connection to this unit made typically? Will the pumps come with factory installed cords long enough to plug in to a receptacle on the building 10 feet away? Are they hard wired into a disconnect on the building 10 feet away? Do I need to install a 4x4 near the pit that will have the disconnect for these pumps and then conduit over to the building?

From what I remember the factory supplied cords were long enough to reach a PVC J-box at the top of the pit.

Question #2: Do I run 2 separate 20 Amp / 240 Volt circuits to the pumps? Or do I run to a small load center (40 Amps) near the pit and then branch off from there?

Either method will work. In the future do you anticipate any other electric needs in this area ? Consider voltage drop and size your

wires accordingly.

Question #3: Since the alarm panel is going to be approximately 70 feet from the actually pit, is there control wiring that runs the length?

Yes either 14 or 12 AWG THHN/THWN would suffice in PVC conduit. The alarm plugs in to a constant hot recptacle, then the control

wires recieve the signal from the pit & sound the horn.

Any advice is appreciated.

I really want to get this job but this is the only item of the bid I am having questions about.

Thanks and Happy Holidays!

Ted
.
 
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hurk27

Senior Member
You stated a sump pump and a treatment plant, both does not go with what your discribing, what you have described is a twin pump ejector pit with a alarm.

Depending upon how fancy the system is designed you could end up with a compleat 3 or 4 float control system with a control panel or a simple single float on each pump, for dwellings the latter is most common, if it does turn out that it is a common single float system per pump they can come both ways hard wired or have a plug in pump and a plug through float switch which this piggy back pulg from the float is pluged in then the pump is pluged into the back of it and the float just switches the pump, one float is normaly set higher so one pump acts like a main and the other a back up.

I use a short (19") Arlington garden post next to the lift station and install two GFCI receptacles with deep inuse covers, these post are low to the ground and look nice as they are dark green, the reason I put the recptacle outside of the pit is a receptacle inside the pit doesnt last very long as the fumes just eat them up, if they are to be hard wired then the Arlington garden post can act as a juntion box to connect the SJO cord from the pumps and floats to your wireing method from the house or use a small inground vault, if this is a simple alarm you will have a float mounted high in the tank with a two wire SJ cord, you can run wire to the alarm box as most are low voltage and the alarm with just have two screw terminals on the box to connect it to.

Is there anyone you can find out what kind of a system it will be, because if it is a 3 or 4 float system with a control cabinet you might want to plan differantly,

Heres a link to the garden post

GP19G
 
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tbakelis

Senior Member
I've been given a schematic by the engineer and it is a 3 or 4 float system with "off float, lead float, lag float, alarm float). I installed a similar panel before, but the alarm panel was directly next to the pit so the float cords went right into the alarm panel. I guess my difficulty in understanding how this will work is now the alarm panel will be 70 feet away. I'm I being stupid (since it's almost midnight) and thinking that 4 pairs of wires will need to run all the way back to the control panel from the floats in the pit?
 

iwire

Moderator
Staff member
Location
Massachusetts
Yes, it sounds like a conduit out from the building to beside the pit or into the pit.

My choice is to install an electrcal handhole right beside the cover to the pit. Run the conduit from the building to the handhole. Now run a second large conduit from the pit to the handhole, run the rubber cords through the conduit into the handhole. Splice the rubber cords to THWN conductors that run to the house.

I would use PVC conduit for all of it, using a 2" between handhole and pit so it is easy to fit all the cords in. I would use a smaller conduit back to the house.
 

tbakelis

Senior Member
Makes sense. And is it ok to run the 20 amp pump circuits in the same conduit as the 8 wires for the Float switches?
 

kwired

Electron manager
Location
NE Nebraska
You say the "alarm panel" is at the main building. Do you mean just the alarm is at the building or is all the controllers at the building?

You kind of get into this being considered a separate building or structure and if so it can not be supplied by multiple feeders or branch circuits.

If the control panel is at the main building the requirements are clear as mud.

If the control panel is at the lift station location, then you need to run a single feeder or branch circuit to the lift station, the lift station must have no more than six disconnecting means, the disconnecting means must be rated as suitable for use as service equipment, and you must have a grounding electrode at the lift station also.

The grounding electrode requirement is going to be in art 250 but the other requirements are all in art 225.

Conductors returning to the main building for alarm equipment is acceptable.
 

tbakelis

Senior Member
The building has a utility closet that the control panel controlling the pumps will be located in. This panel also has the siren and strobe built into it. In other words, all the wiring connects to this panel as well as it being the siren and strobe, all in one.

The pit is located 9 feet away from the building. There is no separate structure for the pit... just the pit.

Do I still need the grounding electrode since there is no separate structure???
 

kwired

Electron manager
Location
NE Nebraska
The building has a utility closet that the control panel controlling the pumps will be located in. This panel also has the siren and strobe built into it. In other words, all the wiring connects to this panel as well as it being the siren and strobe, all in one.

The pit is located 9 feet away from the building. There is no separate structure for the pit... just the pit.

Do I still need the grounding electrode since there is no separate structure???

I don't think there is any question that the pit is a structure, (see art 100 definition of "structure") but whether it is a "separate structure" or not and whether Art 225 Part II applies may not be too clear.
 

ceb58

Senior Member
Location
Raeford, NC
I don't think there is any question that the pit is a structure, (see art 100 definition of "structure") but whether it is a "separate structure" or not and whether Art 225 Part II applies may not be too clear.
I know the definition in Art. 100 is very broad but IMOP it is an integral part of the dwelling. If it is considered a separate structure then you may still get by with 225.30(A)(6)
 

iwire

Moderator
Staff member
Location
Massachusetts
I don't think there is any question that the pit is a structure, (see art 100 definition of "structure") but whether it is a "separate structure" or not and whether Art 225 Part II applies may not be too clear.

Well I have to agree it is a structure, if it is 'separate' will be up to the AHJ in my opinion.



ceb 58 said:
If it is considered a separate structure then you may still get by with 225.30(A)(6)

Maybe, or even 225.30(D)

(D) Different Characteristics. Additional feeders or branch
circuits shall be permitted for different voltages, frequencies,
or phases or for different uses, such as control of
outside lighting from multiple locations.


There are other issues as well that are almost always broken with these pump pits such as rubber cords being run through holes or raceways ......... but in the real world .... at least around me ... these seem to be overlooked due to the application.
 

GUNNING

Senior Member
Lift Station

Lift Station

If its a float system you will have sewer gasses that will need to be sealed and should have seal offs. There are manufactured control panels that work well for lift stations. All the lift stations I have seen have separate control panels and power disconnects Ridged pipe because of the corrosive material and gases that are not something you want to reintroduced into a building. Might want to rethink the closet control panel. It has alarms for a reason, the pits are fenced for another.

The floats fail, keep that in mind when you do your design. Its not pretty when it happens.
 

tbakelis

Senior Member
The float system and control panel have already been specified by the engineer. Just trying to
Figure out the most code correct and efficient way to install the electrical portion of the system.
Seems to be a bit of "grey area" involved with these ejection pits
 

iwire

Moderator
Staff member
Location
Massachusetts
If its a float system you will have sewer gasses that will need to be sealed and should have seal offs. There are manufactured control panels that work well for lift stations. All the lift stations I have seen have separate control panels and power disconnects Ridged pipe because of the corrosive material and gases that are not something you want to reintroduced into a building. Might want to rethink the closet control panel. It has alarms for a reason, the pits are fenced for another.

You are talking a large installation, not a little one.
 

kwired

Electron manager
Location
NE Nebraska
The float system and control panel have already been specified by the engineer. Just trying to
Figure out the most code correct and efficient way to install the electrical portion of the system.
Seems to be a bit of "grey area" involved with these ejection pits

Might want to discuss this with your AHJ. I think many would allow you to install this control panel at the building and consider the lift station to be a part of the building especially if it is only 9 feet away. If it were 100 feet away they may see it differently.

Either way you may need to verify what and where they will accept as a motor disconnecting means for the pump motors.
 

qcroanoke

Sometimes I don't know if I'm the boxer or the bag
Location
Roanoke, VA.
Occupation
Sorta retired........
there are other issues as well that are almost always broken with these pump pits such as rubber cords being run through holes or raceways ......... but in the real world .... at least around me ... these seem to be overlooked due to the application.

Emphasis on real world........
Some things just require common sense. The NEC does not take that into consideration.
It's black or white. No grey area.
 

Cow

Senior Member
Location
Eastern Oregon
Occupation
Electrician
Yes, it sounds like a conduit out from the building to beside the pit or into the pit.

My choice is to install an electrcal handhole right beside the cover to the pit. Run the conduit from the building to the handhole. Now run a second large conduit from the pit to the handhole, run the rubber cords through the conduit into the handhole. Splice the rubber cords to THWN conductors that run to the house.

I would use PVC conduit for all of it, using a 2" between handhole and pit so it is easy to fit all the cords in. I would use a smaller conduit back to the house.

This is how we'd do it around here.
 

hurk27

Senior Member
You are talking a large installation, not a little one.

Even so I still think it would be wise to install a box or hand hole as you stated in your previous post to act as a vapor barrier to block the sewer gasses as you do not want to get them into the control panel, another method I use is to make a sort of P trap out of a couple of 45's and put a little high dielectric oil in it to do the same thing, a PVC J-box on the back of the house using a 90? and two 45?s from the pit will give you a P trap just before the 90? turns up into the J-box that will block the sewer gasses from reaching the J-box or the control panel, as these gases can have a high corrosive content from the soaps and bleach we use in laundry washings and the result if not blocked well lets just say the controls don't last very long.

Here is a photo of a large system I installed with P traps between both the tank and the J-box to the left of the main control cabinet and P traps between the control cabinet and the J-box, each P trap is filled with a dielectric oil I believe it is mineral based transformer type oil and is of a high enough viscosity that it will stay in the traps for a very long time, but will allow for the removal and installation of pumps and floats, on these larger systems I always put in a vapor break J-box but for a dwelling and smaller systems with a control cabinet even if you just install one P trap it should do the trick, also the the J-box in the photo had terminal strips to land the float and pump cords on to make it much easier to change them out.

100_5450.jpg


And a photo of the terminal strips to show the SEO cords coming from the tank:
jpppp008.jpg


Of course using a SS 4R J-box on a home would be an over kill as any WP PVC box would be just fine.

My price I charged for this box alone was over $1500 installed with the terminal strips.
 
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