Wiring for Submersible Pump

Discussion in 'Pumps and Tanks Well Forum & Blog' started by techinstructor, Sep 21, 2011.

  1. techinstructor

    techinstructor New Member

    Messages:
    81
    Location:
    North Carolina
    We have a Myers Predator 2-wire, 1HP, 230 V 5 GPM pump installed in our well at our new home. Currently the pump is wired to a small pressure tank at the well with a cord on it so we can plug it in to our saw service and use it during construction. We are in the process of running the water and electrical lines from the well to the house and I have some questions about the wiring. We plan to have an electrician hook this up but we haven't contracted with someone yet. We need to go ahead and lay the wire in the ditch with the water line, so that it can be covered back up. It's a little over 100' from the well to the house so we want to get this right the first time. ;)

    I need to know how long the new buried wire needs to be. Will it go from the well to the pressure tank switch or does it need to be long enough to go all the way over to the panel box? We plan to run 12 ga. UF ground, direct burial wire from the pump to the house. Is 12 ga large enough to handle the load with 115' (164' to the panel box) of run?

    We also want to be able to add a light in the small well house we plan to build. Do we need to run a second wire for this appliance, since it will be 110v as opposed to the 230v pump or can the electrician connect the light off of the same wire?

    Thank you in advance for your help.
  2. masterpumpman

    masterpumpman New Member

    Messages:
    729
    Location:
    Virginia Beach, VA
    #12 wire wire will be OK. I would run #12 uf w/ground from the well to the pressure switch. I would run #12 w/ground Submersable wire from the pump to the top of the well. I recommend using a Pside-Kick http://www.cyclestopvalves.com/products.html as it includes everything that you will need. The Pside-Kick will keep the pump from cycling and give you city like constant pressure.
  3. ballvalve

    ballvalve General Engineering Contractor

    Messages:
    3,261
    Location:
    northfork, california
    Franklins AIM manual incredibly says 14g copper is good for 250'. I think 12 was good to 500'

    But I dont see the well depth. Maybe its 400'+? Then its back to the book.

    12g UF with ground does not give him the neutral he needs [legally] to meet code for an outlet and a light. Nothing wrong with 240v lightbulbs, however, like the rest of the world.

    If the wells not deep do 14g 3 wire with ground.

    Around here, unless you are on the beach, everyone would use conduit for gophers and rocks. I have often used conduit with a sleeve, say 2" inside of 3" pipe, when crossing road and creeks and rock cuts.

    Be very careful of your electrician - he never read Franklins AIM manual, and he will try and tell you you need 10 gauge or heavier.

    http://www.franklin-electric.com/aim-manual/page-11.aspx

    Your electrician will pull out his NEC book and say you can only go 180' with 10 gauge wire, because he does not understand Franklins motors design. Dont mention the light and plug, or he might be correct in the eyes of the code.

    I saw an idiot electrician wire up my 1/2hp Franklin with 6 gauge copper for about 300' run, because he was too pig headed to look at the chart I handed him. And the homeowner was afraid of him.
    Last edited: Sep 21, 2011
  4. techinstructor

    techinstructor New Member

    Messages:
    81
    Location:
    North Carolina
    I have a document from Myers that has a chart for their pumps that is similar to the chart for Franklin pumps in your link. According to Myers with a 1 HP pump I can go 383 ft with 12 ga wire and 611' with 10 ga. I'm really glad I read Ballvalve's reply because I had failed to add in the distance from the ground to the pump when calculating the length of the wire. I now know that we need to use 10 ga; the total distance from the panel box to the pump will be about 564' so I would have been way over the limit for 12 ga.

    Ballvalve, thanks for the information about the wiring for the light. We'll run a separate UF ground wire for that. At least that can be 14 ga (I guess?).

    And Porky, thanks for the tip about the P-side kick. I'm concerned about the pump cycling as I know that is what wears them out. I'm also concerned about the low yield of my well (2 GPM). I've been told that the pump (1 HP) is too large for that yield; I was not consulted by the contractor who put the pump in. I do have a low pressure cut-off switch for my pressure tank in hopes that I can avoid ever running the pump dry.
  5. cacher_chick

    cacher_chick Test, Don't Guess!

    Messages:
    3,274
    Location:
    Land of Cheese
    You might want to compare the price of running the section from the house to the well with PVC conduit and individual THHN/THWN wires.

    If it needs to be repaired/replaced in the future you can just pull new wires through the conduit.
  6. techinstructor

    techinstructor New Member

    Messages:
    81
    Location:
    North Carolina
    :confused: translate please?
  7. cacher_chick

    cacher_chick Test, Don't Guess!

    Messages:
    3,274
    Location:
    Land of Cheese
    THHN/THWN are specifications for wire insulation. It is the wire commonly seen used for running in conduit. Individual rolls of wire are sold in different gauges and with different colors of insulation. (red, black, white, green, etc.)
  8. ballvalve

    ballvalve General Engineering Contractor

    Messages:
    3,261
    Location:
    northfork, california
    Yes, use conduit and loose wire. You only need a red, black and white, and your ground can be a 12 or 14 gauge.

    Do not waste any money on a seperate uf cable for a light. If you dont want to buy a 240 volt light bulb [thus saving one wire, the white] then you can use a small transformer from an old video camera to power a low voltage light. Most have an input voltage of 120/240 volts and give you 12 or 24 volts out. Your old buicks brake light makes a good well house light.
  9. cacher_chick

    cacher_chick Test, Don't Guess!

    Messages:
    3,274
    Location:
    Land of Cheese
    If I had a wellhouse and was pulling wires anyway, I would run a separate 120V branch circuit for a light and an outlet.

    If your pressure tank and switch is going into the house, The 240 V is only at the well head
    when the pump is running.

    You never know when you might want to plug something in out there.
  10. ballvalve

    ballvalve General Engineering Contractor

    Messages:
    3,261
    Location:
    northfork, california
    I would pull 2] 10's in conduit for the 2 wire pump and then put a good maglite or a stick on LED light in the pump house. Drive a ground rod at the well if it pleases one.

    Or add a 14 gauge white for a neutral and have your daughter take a shower when you need power at the pumphouse. Come off the 10 g wires to a small breaker box - 1] 15 amp light circuit and 1] 30 amp breaker for the pump. You need a pump shut off down there anyway.

    This assumes the pressure switch is at the house.
  11. cacher_chick

    cacher_chick Test, Don't Guess!

    Messages:
    3,274
    Location:
    Land of Cheese
    If you are in need of a code compliant installation, be careful of advice you get from the internet.
  12. techinstructor

    techinstructor New Member

    Messages:
    81
    Location:
    North Carolina
    Would this meet code or are you just joking? I thought we had to run 2 hots and a ground for the pump. But as you can see by my continuing questions I am woefully ignorant when it comes to things electrical.

    The light isn't just for seeing. (Everyone in the family regularly uses headlamps for that!) We've always kept a low wattage bulb on in the well house for a minimum of heat in the winter as extra assurance against freezing. I know that may not be an option in the future when we can no longer get incandescent bulbs.

    Yes, the pressure tank and switch are at the house. I'm trying to understand your idea of adding the 14 ga neutral white wire for the light. I guess the hot for the light would come from the 10 ga wire that also supplies the pump. Are you and cacher-chick saying that the light couldn't be used unless the pump was running? I'm so confused. :eek:

    If we were to choose this option, what would we need for the 120v branch circuit. In the house, it looks like the electrician (who ran the rough wiring for the main floor) ran 12-2 to the receptacles and 14-2 up to the lights. Can I run individual wires for the branch circuit? What do I need: one hot and one neutral? Does this circuit also need a ground? Can these be in the same conduit as the 10 ga wire for the pump?
  13. cacher_chick

    cacher_chick Test, Don't Guess!

    Messages:
    3,274
    Location:
    Land of Cheese
    Yes, you would need a separate hot and neutral wire for a 120V circuit that would always have power. A single insulated ground wire would be sufficient for both the well pump and the receptacles.

    Sometimes a person needs to know his or her limits. Electricity kills people every day. It may be in your best interest to hire a pro to do it correctly and safely the first time.
  14. techinstructor

    techinstructor New Member

    Messages:
    81
    Location:
    North Carolina
    I agree with your assessment. We do plan to hire a pro to hook all this up and run the rest of the wiring in the house. But we need to go ahead and put the wire in the ditch with our water pipe so we can get the ditch covered up before it fills up with leaves, etc. I just want to make we get the right wire so the electrician will have the right stuff to work with.

    Thanks for your help.
  15. cacher_chick

    cacher_chick Test, Don't Guess!

    Messages:
    3,274
    Location:
    Land of Cheese
    Everywhere I have been, this kind of work requires a permit and inspection by the local municipal inspector.
    The inspection must be done before the trench is backfilled.

    Make sure you have all your ducks in a row before you make a lot of extra work for yourself. There are minimum requirements for burial depth of both the water piping and the electric, and there is a minimum separation required between the two. The requirements vary depending on location.
  16. ballvalve

    ballvalve General Engineering Contractor

    Messages:
    3,261
    Location:
    northfork, california
    If you want to heat and light the pump house, pull 2] 10g for the pump and 3] 12g of the correct colors. Install a small sub panel and a ground rod would not hurt, although you have your ground in the green or bare wire of the 12g portion of the run. 3/4" pvc conduit.

    Remember to make your pro read the AIM manual.

    Lots of rules on telephone and electric seperation and sewer and water seperation, but not many on electric and water. I have rarely opened buried conduit that was not full of water anyway. Moral of story, be careful pulling wire not to damage insulation.
  17. techinstructor

    techinstructor New Member

    Messages:
    81
    Location:
    North Carolina
    Update and more questions

    I talked with the electrical inspector. The electrical wires and the water pipe (Pex) can be side by side, whether the wires are UF-B or THWN in conduit. We're like the idea of putting the wires in conduit for all the reasons already stated. When our basement was poured, we had the contractor put in a 2" PVC sleeve for the waterr line, thinking that would suffice for both water and electrical. Now we realize that it isn't large enough for both 1" Pex (1 1/8" OD) and conduit (we don't want to try pulling 5 wires through a small diameter conduit (Dear husband wants to use 2").

    So we're thinking of doing it like this:

    Install 2" PVC conduit for individual THWN wires - 1 each black and red 10 gauge, 1 green 12 gauge, and 1 each black and white 14 gauge - 5 wires in all. The conduit will be laid in the ditch beside the Pex water line. At the junction with the house, we will only feed the Pex through the 2" PVC sleeve that is through the basement wall. Where the electrical conduit intersects the basement, we'll add a long sweep elbow to bring it up above grade so that the wires can be fed through the band, above the basement wall. (Our basement wall has 2" foam insulation and stucco on the outside so we don't want to drill another hole through that.)

    My questions concern the place where the wires enter the house. From what I understand we can put a LB fitting at this location to have a waterproof elbow where the wires turn to enter the house. Do these wires then go to an interior junction box mounted inside on a joist? Is this acceptable to have splice in the wire at this location or should the wires be continuous all the way to the pressure tank? (I've also seen mention of an exterior junction box that could be used in lieu of the LB fitting and interior box, but the same question concerning the splice applies.)

    Since we're running wires for both the pump and the light, do we need to have a separate junction box for each or will the one box suffice?

    One more question... does anyone use lubricant on the wires for easier pulling? If so, what do you use?
  18. cacher_chick

    cacher_chick Test, Don't Guess!

    Messages:
    3,274
    Location:
    Land of Cheese
    2" is really overkill for conduit. You can pull two 10's and 3 12's through 1" conduit and have plenty of room left for more. There is no benefit to installing 14g,and it limits the circuit to 15 amps.

    From the LB at the house, a piece of conduit goes through the band. Once you are inside, you can continue the conduit to wherever you will separate the 120 and 240 branches in a junction box. From the junction box the 10ga wires go to the pressure switch, while the others go the main panel. The wires need to be in conduit, or you could switch to NM-B (romex)or whatever your house is wired in from the junction to the end.

    It's always better to run a single length of wire when you can, rather than splice sections together.

    You will find cable pulling lubricant in the same place you buy conduit and wire.
    Last edited: Sep 27, 2011
  19. ballvalve

    ballvalve General Engineering Contractor

    Messages:
    3,261
    Location:
    northfork, california
    3/4" conduit is fine. 2" is absurd. look up wire fill charts for conduit. You can lay them [the wires] out and feed them through individual 10' sections with a 1/4" steel pencil rod or whatever suits you. No lube, no pull. You slip the pipe over the wires.

    Frankly, with 2" conduit you could run the pex INSIDE the electrical conduit and still get the wires in. A great idea that no electrician will perform, unfortunately.

    I once ran 400 feet of submersible well wire INSIDE the 1" water line, with rather interesting home made wire exits on either end. This was due to impossible terrain, and a bit of an experiment.... But no-one inspects wells around here. If you can run pump wire down a well, you can run it in the water stream also. Still working fine after 10 years.

    Why use pex? PVC is cheaper and PEX has a rather unknown history for underground use.

    For a real pull, and for finding leaks in tires and washing dogs, I never leave home without a 1 gallon pump up sprayer about 20/80 [as you please] dish soap to water.

    The other secret is the same type sprayer, 1 part diesel, 1 part gear oil, 1 part any light oil or engine oil or hydraulic fluid or transmission fluid you can muster up. Used hydraulic fluid from a tractor works fine also and recycles it for free. Not for wires, but corrosion proofing tools and replacing that ridiculous wd40 for any use you can think of. Spray your wooden handled tools once a year and you get an extra 10 years out of them.
  20. techinstructor

    techinstructor New Member

    Messages:
    81
    Location:
    North Carolina
    Update and another question

    As per advice, we are using 10 ga red and black for the pump and 12 ga black and white for the light. We were going to get 12 ga green for the ground but they didn't have enough at Lowes so we paid a little extra to get 10 ga ground wire which they had in stock.

    We decided to run 1 1/4" conduit to the house and then up to the band. (The 2" sleeve in the basement wall, originally for the water line only, isn't large enough for conduit and the 1" Pex.) At the band, we'll put a 1 1/4" LB fitting and then run the conduit through to a junction box that will be mounted on the inner band. (The basement wall is 10" thick. The last of the "joists," installed on 16" centers, actually sits on top of the inner edge of that 10" concrete wall and the outer band sits on the outside edge. We'll have to go through both of these.)

    Now for my question. We want to mount a junction box so that the 1 1/4" conduit intersects with the back of the box. Then we want to have two 3/4" junctions going out the side and bottom of the box. One will 3/4" outlet will go to the pressure tank; the other will go to the panel box. Here's a photograph showing the fittings. In the photo, the face that is up would actually be rotated to vertical and mounted to the side of the inner band (a 2 x 12).

    [​IMG]

    My husband was familiar with junction boxes that had knockouts, but the ones we found at Lowes were solid, so I assume that we drill for the size hole we need and insert the conduit adapter through that hole. Then use a a coupling to join the conduit to it. Are there any restrictions as to where holes are drilled in these junction boxes? It will be installed inside so moisture isn't an issue. There may be a better way, but if you think this will work, we've already got the parts and are ready to install them. Feedback is welcomed.
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