Chiller question!

Discussion in 'Test Kits, Controllers, Reactors and Dosers' started by Renier, 21 Jan 2013.

  1. Renier

    Renier

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    Hey guys & gals

    I received a chiller for free...
    the on-board thermostat was broken so I wired it up to an independent
    digital temp controller with its own probe.

    So now the chiller only switches on when temp goes over the desired set temp.
    I have a 3500 l feed pump (I know this is probably to big but its what I have now)
    can I wire the pump so that it only comes on when the temp exceeds the set temp
    or will the water in the chiller and pipes become stale if the feed pump doesn't run continuously?


    thanks
     
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  3. tyronvs

    tyronvs

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    I say run the pump all the time
     
  4. Renier

    Renier Thread Starter

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    that's what I'm thinking but if I can save some electricity that would be nice
     
  5. RiaanP

    RiaanP Moderator

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    you answered yourself. :)
     
  6. RocketRooster

    RocketRooster

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    Get a dial timer (the ones with the little switches around the rim), that way you can let it run intermittently to flush every now and again. Run it in parallel bypass with the thermostat so that the thermostat supplies continuous power when needed.
     
  7. RiaanP

    RiaanP Moderator

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    not all pump rotors can handle being switched on and off frequently
    Especially where the impeller and the magnet are 2 separate things that clips together. Eventually the piece of plastic that let them run together strips and then the magnet turns but not the impeller
     
    Last edited: 21 Jan 2013
  8. Dillan

    Dillan

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    I think going on and off would be very bad for the compressor in the unit. Turning a fridge on and off is very bad for it so I have heard so I assume the same would apply to the chiller.

    And you got it for free so look at starting with having a R3000 credit with Eskom;)
     
  9. leslie hempel

    leslie hempel Moderator MASA Contributor

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    Why not run a bypass from your return? and feed some water through the chiller entering back into the compartment it was pumped from?

    1 pump no extra juice cost and chiller operating?/

    win win win :)
     
  10. brentnorm

    brentnorm

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    Surely if you are pumping the chilled water back into the chamber it has been pumped from you will only really be cooling that chamber and then the chiller will switch off ? Sure some of the chilled water will circulate into the display but I think the efficiency won't be optimal.
     
  11. RocketRooster

    RocketRooster

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    Evaporative cooling compressors run in a bath of oil and are very reliable. Fridges switch on and off all the time with no ill effect - a chiller uses the exact same technology, I don't see any problems tbh if you set it for 1 hour on, two hours off, etc.
     
  12. RocketRooster

    RocketRooster

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    This is how I would wire it. The timer does its thing all the time - if the thermostat switches the chiller on then the chiller is on regardless of what the timer does. If the thermostat is off, the chiller will only run according to the timer's settings.

    Of course, the chiller needs to be grounded but I ommitted that for simplicity.

    ChillerCircuit.jpg
     
    Last edited: 22 Jan 2013
  13. leslie hempel

    leslie hempel Moderator MASA Contributor

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    if you plumbed the flow in such a way that 1/3 the water went through the chiller and 2/3 went to the DT the water entering where the cilled water returned would be dilouted by the warmer water..


    either way i have done this and i had a constant temp of 26 deg and no problems ;)
     
  14. RocketRooster

    RocketRooster

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    I'd do a gravity feed to the chiller, so no pump except the main return pump. And then just use a separate thermostat, no timer needed.
     
  15. leslie hempel

    leslie hempel Moderator MASA Contributor

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    if you gravity feed you need to ensure no obstructions go into the piping.. snails etc.. otherwise you will have a expensive ornament ...
     
  16. Nur

    Nur Starz

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    +1
     
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