Connect with us

Pool chlorinator

Discussion in 'Hobby Electronics' started by Trevor Wilson, Nov 4, 2006.

  1. Any thoughts on solving the following issue?

    I have a Saltmate pool chlorinator. For those who don't know, the operation,
    as I understand it, is that two plates are immersed in a salt solution (the
    pool water). Current is passed through across the plates, releasing chlorine
    into solution. Problem is the plates end up white crap on them, requiring
    immersion in acid to clean. The white crap only adheres to one of the
    plates. According to the back panel, maximum current is 20 Amps at 6 Volts
    DC. The current is controlled by a couple of Op amps, a pot and some other
    stuff, which drives the gates of two, parallelled 65 Amp SCRs.

    I spoke to a mate who sells pools and he informed me that the latest models
    employ a polarity reversing scheme, which virtually eliminates white crap
    build-up. I like that idea.

    Anyway, after a little thought, I figure on adding a couple of relays. One
    to switch the DC output and one to switch the mains. A 555 timer will switch
    the mains off, first, then switch the DC relay, to prevent any contact
    welding issues. Switching frequency will be once every 30 mins or so.

    Any suggestions for a better system will be gratefully received.
     
  2. Borat

    Borat Guest

    Ours is a Chloromatic ESC-16. It's supposted to be a no clean type.

    http://www.monarchpoolsystems.com/home.html

    It has 3 connections - 2 to the electrodes/plates, the 3rd is a sense
    electrode - a stainless bolt head. The bolt head is between where the
    electrodes entedr/exit the housing and is on the upstream side. The
    electrode connection metal work is insulated from the water until it enters
    the plate assembly. It seems to work in an on/off fashion with the control
    adjusting the duty cycle - ie run for x minutes, off for y minutes.
     
  3. Franc Zabkar

    Franc Zabkar Guest

    You *may* have trouble with the gas sensor. AIUI, the chlorinator must
    sense a current between the gas sensor electrode and one of its
    primary current carrying electrodes. An absence of current means that
    the sensor is uncovered and probably enveloped in hydrogen, which in
    turn means that the chlorinator will not turn on. I'd verify whether
    the sensing circuit is polarity sensitive, and if so, I'd switch it as
    well. Some time ago I reverse engineered a chlorinator of this type.
    If I can find the circuits I'll email them to you.

    - Franc Zabkar
     
  4. You *may* have trouble with the gas sensor. AIUI, the chlorinator must
    sense a current between the gas sensor electrode and one of its
    primary current carrying electrodes. An absence of current means that
    the sensor is uncovered and probably enveloped in hydrogen, which in
    turn means that the chlorinator will not turn on. I'd verify whether
    the sensing circuit is polarity sensitive, and if so, I'd switch it as
    well. Some time ago I reverse engineered a chlorinator of this type.
    If I can find the circuits I'll email them to you.


    **Thanks Franc. I note that the top of the line Saltmate also has an extra
    'electrode'. I suspect you are correct and that it is some kind of sensor.
     
  5. Poxy

    Poxy Guest

    Why should it matter if the electrodes are uncovered? Is it for fear of
    accidental sparking setting off hydrogen that might be there?
     
  6. Borat

    Borat Guest


    Or maybe to stop the build up of a pocket of chlorine gas? Very nasty stuff
    to breathe.
     
  7. Two Bob

    Two Bob Guest

    Any thoughts on solving the following issue?
    Check out directpoolsupplies.com.au
     
  8. Jeff

    Jeff Guest

    my 2 cents worth...
    When I looked in to doing the same sorter thing with my unit, I found due to
    the special coatings on the "Cell" (to make it more efficient) when
    reversing the polarity it reduced the current flow to a level that made the
    idea not workable.

    My research lead me to the understanding (of the auto cleaner type) that
    they use a different type of cell.
    As I had just paid for a new one - it was not practical for me to look into
    this further.

    With my experience I located and use a salt supply that doesn't leave as
    much on the plates and I don't run the cell for a day or so after putting in
    the salt.

    But it is still about once a month for me, and I found it's best to dilute
    the acid a bit - to "save" the coating on the cell.

    Jeff

    ---------------------
     
  9. I worked on a product similar to this many years ago. I left the
    company because I got nervous about how much copper the system
    actually put into the water.

    IT basically uses 2 copper electrodes (might have a small silver
    content, but I am not sure) and deposited copper in the water. In very
    small amounts, copper is fine ( think the body needs it), but it is
    poisonous in large amounts. IF one has a chlorinator of this type
    which purposely deposits copper into the water then it is wise to have
    the copper content of the water tested regularly.
     
  10. Ross Herbert

    Ross Herbert Guest

    Something similar to this system?
    http://www.triangularwave.com/b3a.htm
     
  11. **Thanks for all the responses. I contacted Saltmate (something I should
    have done first) and found them to be very helpful. Of course Saltmate
    suggested that my idea of reversing the Voltage at the plates was an
    over-simplification and that their system was a good deal more complex and
    sophisticated (I expected a response such as this), but that the real
    problem was the electrodes themselves. Apparently, they're constructed from
    a titanium base material, coated with platinum. My electrodes have a
    standard coating on the cathodes and a 6 X thickness coating on the anodes.
    The self cleaning electrodes have a 6 X coationg on both sets of electrodes
    (makes sense). The cost of the cell (the part with the electrodes in it) is
    around $800.00! Fabricating titanium electrodes is well beyond my abilities.
    I don't even want to think about platinum plating.
     
  12. Copper/silver ionizers have been used in pools for decades, and they
    do help in controlling algae (copper is an algaecide). You can also
    buy copper additives that are very effective, though the copper
    precipitates out as bicarbonate within a week or so - hence continual
    replacement by an ionizer is effective. Copper discolours some fabrics
    and hair BTW.

    There is a number of other non-chlorine algaecides, various amines and
    quaternary ammonium ones: rosin amine D-acetate, cetyl trimethyl ammonium
    bromide lauryl pyridium chloride, etc.

    With any of them, you still need chlorine anyhow, as they, like copper,
    don't control bacteria.
    The bad smell of a public pool isn't typically chlorine, but chloramines,
    which are caused by a buildup of body wastes (urine mainly) which break
    down to ammonia compounds.

    I have a pretty comprehensive document from the CSIRO about pool water
    treatment here. The product manufacturers stuff is all pretty biassed
    and unscientific IME. The CSIRO document is really good!

    The important point in maintaining effective sterilization with minimal
    chlorine content is to keep the TDS (total dissolved solids) down to
    the minimum required for pH buffering, plus maybe a bit of isocyanurate
    stabiliser. All non-carbonate ionic content does is lock up chlorine so
    it's effectively unavailable. We recently had to fix our pool which had
    reached 5000ppm TDS, when it should be maybe 300ppm, due to us not
    wasting enough water through backwashing!

    Clifford Heath.
     
Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Electronics Point Logo
Continue to site
Quote of the day

-