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Extending life of well pump relay...??

Discussion in 'Home Power and Microgeneration' started by sno, Feb 11, 2010.

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  1. sno

    sno Guest

    I just replaced my well pump relay due to arcing wearing away the
    contacts...

    It seems I am replacing the relay about every 1.5 to 2 years...and it
    seems to happen always in the middle of winter...it is a bummer to
    replace it when the weather is bad...I would like to get maybe 6 more
    months out of one....

    The pressure tank is fine...I realize that if I get a bigger tank the
    pump would cycle less....but do not want to spend the money on a bigger
    tank especially when the tank I presently have is good....

    I seem to remember something about hooking up a capacitor in some manner
    to prevent arcing on relays....does anyone have any ideas or know how to
    hook up capacitor...??....and the value that is needed...
    or any other tricks...??....the pump is wired to work at 110 volts AC...

    thank you for any help....have fun....sno
     
  2. Ecnerwal

    Ecnerwal Guest

    Snubber: for instance (a little ways down the page)
    http://www.allaboutcircuits.com/vol_4/chpt_4/2.html

    I wonder if you are low-balling the quality of your pump relay, since
    the typical square D relay works many years without trouble.

    Anyway, to avoid burnt contacts - use a Solid State Relay - no contacts
    to burn, no moving parts.

    Since the well industry is so far behind everything else electrically,
    you probably can't do this in one part.

    Use the pressure switch to switch the input to a SSR that is at least
    twice (and more is better) the rated amperage of your pump. Use the SSR
    to actually control power to the pump. And get another pressure tank
    (you can add one, rather than having to throw away a good one and
    replace it with a bigger one - and the one you add does not need to be
    where the first one is.)

    Then again, an SSR may die even faster, if the real problem is that you
    need to bond your well casing to your grounds, and put surge arrestors
    on the well wiring. Delta LA302 or LA302R (easier to find at reduced
    price, but not quite as beefy as the LA302) and perhaps a CA302R for
    good measure. Lighting can play havoc with wells.
     
  3. sno

    sno Guest

    Looks like a snubber is the easiest way to go....will try it....
    googling snubber leads me to believe a 100 ohm resistor and 100 or
    greater nanofarad capacitor with voltage of about 600 volts or so should
    work...

    thank you very, very much for the help and information....have fun....sno
     
  4. Guest

    Have you checked the current draw of the pump against its specs? If
    you have a control box, have you checked it out?

    Your short relay life is highly unusual in my experience, even the
    cheapest contactors seem to last a long time. Although I have seen a
    couple of cases of pressure switches failing every few months, caused
    by ants. For whatever reason they're drawn to the contacts and
    immolate themselves. Fix is to move or seal off the switch.

    Wayne
     
  5. sno

    sno Guest

    I suspect the short life is due to the fact that I have to keep water
    flowing all winter to prevent freezing...is not possible to bury piping
    below frost depth....also during winter heat only one room, pipes in
    house can freeze...(both have frozen in past)....which leads to all
    sorts of problems....<grin>

    have fun.....sno

    --
    Correct Scientific Terminology:
    Hypothesis - a guess as to why or how something occurs
    Theory - a hypothesis that has been checked by enough experiments
    to be generally assumed to be true.
    Law - a hypothesis that has been checked by enough experiments
    in enough different ways that it is assumed to be truer then a theory.
    Note: nothing is proven in science, things are assumed to be true.
     
  6. Guest

    I still think it's unusual. A common failure mode is pressure tank
    fails, then pump fails due to crazy number of cycles. Yet the pressure
    switch or relay is still OK, and that includes the ones switching
    higher horsepower. Anyway, another cheap and easy fix that might work
    for you - 2 relays in parallel.

    Wayne
     
  7. Bob F

    Bob F Guest

    I don't think that really helps. Do to slight differences in opening/closing
    times, one relay ends up taking the switching load.
     
  8. sno

    sno Guest

    AHHHH....Great idea...!!!...thank you....have fun....sno


    --
    Correct Scientific Terminology:
    Hypothesis - a guess as to why or how something occurs
    Theory - a hypothesis that has been checked by enough experiments
    to be generally assumed to be true.
    Law - a hypothesis that has been checked by enough experiments
    in enough different ways that it is assumed to be truer then a theory.
    Note: nothing is proven in science, things are assumed to be true.
     
  9. Guest

    Sure, but the object is to have one relay working. Consider it as
    having the replacement waiting in the wings. :)

    Wayne
     
  10. You

    You Guest

    Finally, someone who is thinking of fixes that are 21st Century
    Technology... I mean really, all this 20th Century Technology is fine,
    but antiquated... A good SSR, with 120, or 240 Vac Control isn't all
    that hard to come by... ANY good electrical supply House will have them
    Off the Shelf... I mean Really... who uses contactors these days....
     
  11. Guest

    For residential water wells - pretty much everybody except those with
    the constant-pressure variety. The OP's contactor is probably the
    usual open-frame type commonly used for up to about 3 hp. They cost
    about $8 and tend to last for a decade or more. Pressure switches cost
    about $15. Primitive yes, but cheap, effective, and available at the
    local hardware store (sometimes at silly prices) in rural areas.

    Wayne
     
  12. sno

    sno Guest

    I ordered the parts today for a snubber....will see if arcing
    stops....if it does not then will borrow some test equipment and see if
    I can figure out what is going on...

    The pump itself is about 10/15 yrs old in that time the only thing that
    has gone wrong is some rocks got sucked up somehow and had to replace
    impeller....

    I had a new switch box installed last year and wire was completely
    replaced....so probably not a wiring problem, in addition have not had
    relay last in all the time have had the pump....this is first time have
    replaced relay since the new wiring....about the same time period as in
    the past.....

    Have noticed that the contacts only arc on one side...maybe because one
    side opens before other...??....one side opens hot wire
    the other opens neutral...

    Anyway will see how the snubber works....and then go on from there....

    Thanks everyone for their thoughts and help....have fun.....sno
     
  13. sno

    sno Guest

    It cycles aprox. every 1.5 minutes....when I have three faucets running
    (bathroom tub and sink faucets full on) the pump runs continuous....that
    works out to 960 cycles per day....28800 per month....during winter
    about 3 months...86400 cycles..
    which works out to somewhere between 50,000 to 100,000 per year....about
    the 100,000 is rated for....so as I suspected, reason for not lasting is
    the water running in winter....

    If snubber works should greatly extend the life...

    thank you for your help....have fun....sno
     
  14. sno

    sno Guest

    good idea....will try it with the snubber....
    Have been thinking....if snubber does not work....have a friend who
    works for a plumber....maybe can get a used hot water non leaking water
    tank...and add it to the system as a pressure tank without bladder...a
    40 gallon tank would take some time to fill up....and i have the room
    for it next to my present hot water tank.....

    thanks for your ideas and help.....have fun.....sno
     
  15. Guest

    Used like that a 40 gallon tank wouldn't add much capacity. And
    conventional tanks are a pain compared to bladder types.
    http://www.nationaldriller.com/Articles/Column/c04c543281b39010VgnVCM100000f932a8c0____
    http://www.inspectapedia.com/water/WaterTankMath.htm

    80 gallons is a common size for bladder tanks. At 30/50 (cut-in and
    cut-out pressure in psi) they hold about 25 gallons of water.

    Have you verified proper pre-charge in your existing tank?
    http://www.inspectapedia.com/water/Water_Tank_Bladder_Adjust.htm


    Wayne
     
  16. sno

    sno Guest

    yep....have verified present tank is ok...and at proper pressure...
    the 40 gallon tank would be used along with the bladder tank....
    even if I had to drain the 40 gallon every two months or so would be a
    great help....and during summer could have a valve to cut it out of the
    system...maybe would be able to get by draining it right before winter
    and right after....I am hoping by adding snubber will solve my problem..
    I have the components on order and it will cost less than 10 dollars...
    will update how things work....when I get done....<grin>

    thanks for info on non bladder tanks....have fun...sno


    --
    Correct Scientific Terminology:
    Hypothesis - a guess as to why or how something occurs
    Theory - a hypothesis that has been checked by enough experiments
    to be generally assumed to be true.
    Law - a hypothesis that has been checked by enough experiments
    in enough different ways that it is assumed to be truer then a theory.
    Note: nothing is proven in science, things are assumed to be true.
     
  17. sno

    sno Guest

    You have to go back and read the whole thread....I keep tap running all
    winter to prevent freeze up...cannot bury pipes deep enough to keep them
    from freezing...I only heat/live in one room in winter so pipes run
    through furthest wall can freeze. As figured out everything is ok
    except running the water all winter causes to many cycles of
    relay...causing replacing of relay (burnt contacts) about every 1.5/2 yrs.

    LOL....what you are talking about everyone who works with electricity
    for any length of time has discovered....first make sure it is plugged
    in....second turn on all switches....<grin>
    third remember electricity is really magic...<grin>...and sometimes what
    seems like the impossible can happen....

    have fun......sno
     
  18. vaughn

    vaughn Guest

    Perhaps, but that is all I ever had on my last home's system and I got along
    just fine. It works best if you own an air compressor. Just at a Schrader
    valve somewhere on the tank and blow in the occasional tank full of air.

    Vaughn
     
  19. Guest

    Sure, lots of people do well with pressure tanks that size. Usually
    the ones using sensible amounts of water. The problem arises when
    you're using more, say running multiple outlets at once. Then you get
    rapid cycling. Wait, what were we talking about again? ;-) Anyway,
    considering the trouble people manage to get into with bladder tanks,
    I never mention conventionals except to DIYers. They're still popular
    though in some large installations in my area. One I remember was
    perhaps 2000 gallons, and had a small auto-start compressor installed.
    That kind of thing, and pressure tanks in general, are headed towards
    extinction though as constant-pressure pumps become more popular. Some
    types of those are already cost-effective, like this one
    http://www.deanbennett.com/constant-pressure-centrifugal-pumps.htm
    that I used to replace a multi-tank conventional setup. Available in
    lower capacities also. For lift apps, these are neat, albeit
    expensive. http://www.deanbennett.com/artesian-vfd-drives.htm. Still,
    when you consider that they can sometimes be used to eliminate one
    pump, a storage tank, pressure tank(s), controls, and motor protection
    devices, they're pretty slick.

    Wayne
     
  20. Ecnerwal

    Ecnerwal Guest

    Another option is "inside the pipe heat tape". If it freezes up, turn on
    the heat, when it thaws enough for water to flow, turn off the heat
    until it freezes again. Probably use a lot less power than running the
    pump all the time, too. If you have a septic system, also much better
    for that than running water all winter. Works better if you insulate the
    waterline.

    Of course, if you insulate the waterline with sheet polystyrene (XPS,
    waterproof, ground contact, usually pink, blue or green rather than
    white) far enough sideways, it's just as effective as burying the pipe
    deeper, and uses no power. A pipe with a 4 foot wide sheet of insulation
    centered over it (right on top of the pipe) that is then buried 1 foot
    deep is effectively the same as burying the pipe 3 feet deep.
     
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