New well pump runs at slightly high Amps.

Discussion in 'Pumps and Tanks Well Forum & Blog' started by JQ, Aug 27, 2012.

  1. JQ

    JQ New Member

    Messages:
    12
    Location:
    MD
    Just put in a new well pump (Goulds 10GS10). I know it is slightly oversized (220 foot well, ~100+ ft static head) and I am already planning on adding CSV, etc. to modulate flow. But in the meanwhile, I noted that the brand new pump is drawing ~9.1-9.2 amps. This is right at its SFA rating, and two amps above the full load rating. The amperage does not vary much over the time its running, so it is not just start-up draw. While testing, I measured AT LEAST 13GPM into 50PSI tank pressure, which on the Goulds charts is consistent with a 120 foot static head estimate. (That measurement was very sloppy and it could be as high as 16 GPM.)

    Question: Am I just seeing the high amperage because the pump is operating at the far right of its curve? Or should I worry there is something wrong with the new pump and take other test steps before installing more components?

    If I am just under-loading the pump then I assume throttling it down will make everything happy. But I'd appreciate comments from someone smarter and more experienced than me.

    Thanks!
  2. LLigetfa

    LLigetfa DIYer, not in the trades

    Messages:
    4,066
    Location:
    NW Ontario, Canada
    There are other factors such as wire size and service feed voltage. Also, if my understanding of how Goulds builds their pumps is correct, the impellers are individually floated so increasing the head pressure/reducing GPM may not vary the amperage as much as other designs.

    That said, I'm sure someone more knowledgeable with Goulds pumps will be along soon.
  3. valveman

    valveman Moderator Staff Member

    Messages:
    4,495
    Location:
    Lubbock, Texas
    I am showing the SFA on a 1 HP is 9.8 amps. Subs are always loaded into the service factor. The pump is fine. Reducing the flow rate with a CSV will reduce the amps. Even with a Goulds impeller design they should drop from 9.1 to maybe 7 when pumping very little water. 9.1 amps won’t hurt anything as long as it is not cycling on and off.
  4. JQ

    JQ New Member

    Messages:
    12
    Location:
    MD
    Thanks. Looks like the new centropro motor SFA is down at 9.1 in the manual, I wonder if they short you a few % of baseline HP and then make it up in service factor... I hear you, thanks for the feedback.

    By the way, in an unrelated question -- you have any opinions on ABS vs. Cast Iron well caps? Seems trivial, but maybe not.
  5. valveman

    valveman Moderator Staff Member

    Messages:
    4,495
    Location:
    Lubbock, Texas
    I don’t know why they would reduce the service factor on that Centripro motor. That is the same 10GS10 pump end they use to put on a 1 HP Franklin motor, which apparently needed 9.8 SFA.

    I had rather use the one piece ABS well seal than the two piece cast iron.
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