Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 8 of 8

Thread: New pump or motor replacement: decision time

  1. Back To Top    #1
    frbruno64's Avatar
    Join Date
    Jun 2015
    Location
    Berwyn, PA (Philadelphia suburb)
    Posts
    20

    New pump or motor replacement: decision time

    As mentioned in my previous thread, I'm planning to upgrade to a two speed pump.

    Replacing the motor with a two speed Century B2983 and keeping the wet end was the original thought. However, it occurred that an analysis of purchasing a new pump is in order, especially if my current equipment is oversized.

    Determining if my current SFHP 2.2 pump is oversized is beyond me, but I'm inclined to consider it's oversized after reading posts on this forum. Thus, I'm asking the folks on this site to chime in.

    Attached is a diagram showing pool piping and equipment.
    • Pipe routing is a logical guess
    • Location of splices is purely to keep the diagram neat
    • At the pad, there are two 1.5" suction lines into the pump and one 1.5" return out of the filter
    • Pump is a Challenger CF-NI-2A High Flow pump


    For an estimate of pipe length, I measured horizontal distances along the pool perimeter from the pump to skimmers, return ports and drain. I added 9" for the drain vertical drop
    Total length of 1.5" suction piping:75'
    Total length of 1.5" return piping: 85'
    Piping between pump and filter is 3' of 2" PVC with two 90 degree elbows.


    • 33,000 gallons
    • Pool only, no features or spa
    • FNS+ 48 filter
    • Equipment pad on level with coping
    • Existing pump wired 220 volts.
    • Multiport valve is Purex Triton with 2" ports
    • No heater
    • 1" eyeballs
    • Skimmers are Baker Hydro from 1971
    • Drain not routed through skimmer
    • Electricity is 15 cents/kw


    The questions on the table are:

    1. Determine the appropriate pump capacity required for this pool
    2. Determine if current pump is oversized
    3. If oversized, identify a suitable two speed replacement pump
    4. Recommendation on replacing motor or installing a new pump


    I'm looking for the right option for the long term, not just the cheapest option. Other considerations are:
    • the age of the current wet end
    • optimal filter performance
    • operating cost inefficiency if the current pump is oversized


    Thanks in advance for any help.
    Attached Images Attached Images
    33k, IG Pebble, 1.5hp Challenger, Pentair FNS, TF-100

  2. Back To Top    #2
    mas985's Avatar
    Join Date
    May 2007
    Location
    Pleasanton, CA
    Posts
    11,487

    Re: New pump or motor replacement: decision time

    The pump is probably oversized for the pool if you run at full speed most of the time. But if you are running on low speed most if not all the time, then not so much.

    Since you have two skimmers, you might want a slightly larger pump for them to work properly on low speed.

    The third skimmer in the middle of the pool is actually a main drain correct?

    A VS would allow more fine tuning of flow rate to get the skimmers to work at a minimum flow rate.
    Mark
    Hydraulics 101; Pump Ed 101; Pump/Pool Spreadsheets; Pump Run Time Study; DIY Acid Dosing; DIY Cover Roller
    18'x36' 20k plaster, MaxFlo SP2303VSP, Aqualogic PS8 SWCG, 420 sq-ft Cartridge, Solar, 6 jet spa, 1 HP jet pump, 400k BTU NG Heater

  3. Back To Top    #3
    frbruno64's Avatar
    Join Date
    Jun 2015
    Location
    Berwyn, PA (Philadelphia suburb)
    Posts
    20

    Re: New pump or motor replacement: decision time

    Yes, the main drain is in the middle and was incorrectly labeled. I corrected the diagram with the proper label. Thanks for noticing my error.

    Note that the current motor is single speed. All we have is full blast!
    33k, IG Pebble, 1.5hp Challenger, Pentair FNS, TF-100

  4. Back To Top    #4
    mas985's Avatar
    Join Date
    May 2007
    Location
    Pleasanton, CA
    Posts
    11,487

    Re: New pump or motor replacement: decision time

    My comments were based on IF you chose to replace the motor with a two speed.
    Mark
    Hydraulics 101; Pump Ed 101; Pump/Pool Spreadsheets; Pump Run Time Study; DIY Acid Dosing; DIY Cover Roller
    18'x36' 20k plaster, MaxFlo SP2303VSP, Aqualogic PS8 SWCG, 420 sq-ft Cartridge, Solar, 6 jet spa, 1 HP jet pump, 400k BTU NG Heater

  5. Back To Top    #5

    Join Date
    May 2013
    Location
    Massachusetts
    Posts
    146

    Re: New pump or motor replacement: decision time

    It's up to you. I don't find anything beneficial to them personally, at least not worth the price. You don't even need to run the pump that much. Just follow the BBB method.

    When my motor was on the fritz I bought a new one on Amazon for $150 and haven't regretted it one bit.
    25,000 Gallons Inground, Gunite
    DE, Hayward Filter
    Loud pump
    Hayward navigator cleaner, leaf hose suction

  6. Back To Top    #6
    frbruno64's Avatar
    Join Date
    Jun 2015
    Location
    Berwyn, PA (Philadelphia suburb)
    Posts
    20

    Re: New pump or motor replacement: decision time

    Now I understand your point.
    33k, IG Pebble, 1.5hp Challenger, Pentair FNS, TF-100

  7. Back To Top    #7
    mas985's Avatar
    Join Date
    May 2007
    Location
    Pleasanton, CA
    Posts
    11,487

    Re: New pump or motor replacement: decision time

    Quote Originally Posted by weird_tolkienish_f View Post
    It's up to you. I don't find anything beneficial to them personally, at least not worth the price. You don't even need to run the pump that much. Just follow the BBB method.

    When my motor was on the fritz I bought a new one on Amazon for $150 and haven't regretted it one bit.
    So saving over 75% in energy costs is not beneficial? You can easily make up the extra cost of the two speed motor in a fairly short period of time.
    Mark
    Hydraulics 101; Pump Ed 101; Pump/Pool Spreadsheets; Pump Run Time Study; DIY Acid Dosing; DIY Cover Roller
    18'x36' 20k plaster, MaxFlo SP2303VSP, Aqualogic PS8 SWCG, 420 sq-ft Cartridge, Solar, 6 jet spa, 1 HP jet pump, 400k BTU NG Heater

  8. Back To Top    #8

    Join Date
    May 2013
    Location
    Massachusetts
    Posts
    146

    Re: New pump or motor replacement: decision time

    Quote Originally Posted by mas985 View Post
    So saving over 75% in energy costs is not beneficial? You can easily make up the extra cost of the two speed motor in a fairly short period of time.
    No it definitely is beneficial. For somewhere where they run the filter 12 months a year it probably makes more sense. Here in the Northeast it's basically 3 months a year.
    25,000 Gallons Inground, Gunite
    DE, Hayward Filter
    Loud pump
    Hayward navigator cleaner, leaf hose suction

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •