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  1. #1
    Join Date
    Jun 2006
    Location
    Omaha, Nebraska
    Posts
    861

    Manitowoc With Cloudy Ice

    I don't work on ice machines often so I'm a bit rusty. Lately I'm doing a lot of them.

    We get abandoned restaurants frequently on the island. The owner gives up, shuts off the breakers and leaves with food still in the coolers, etc.

    Today I worked on a Manitowoc S series (2004 vintage) that hadn't run for at least 6 months. I've never worked on one of these before, most of what we have are Ice-o-matics. The board was burnt, but after replacing it and running a few harvest cycles the ice is still cloudy. I did a quick cleaning and the water runs clear. It's not running low on water toward the end of the freeze cycle, and the pump doesn't seem to be sucking air. I think it might be a tad low on charge. The suction gets down to about 22 psi (404A) at the end of the harvest. Harvest is also slow, about 3 minutes, 80 psi suction.

    The dishwasher told the new owner that it never worked right since they moved the condenser. It's about 20 feet away and the lines are even insulated. There's no cycling control so the fan runs all the time. Not sure what's wrong here.

  2. #2
    Join Date
    Nov 2001
    Location
    east kansas
    Posts
    8,027
    Refrigerant charge has nothing to do with cloudy ice.

    Since it's not sucking air, I'd look to see if the dump valve is opening during harvest.

    Also make sure the drain line is sized correctly and there is a vent. Goes to making sure enough water is being flushed after each cycle. Might need a water filter.

    Clean water, clean machine, then refrigerant problems. Try to keep your guages off the machine.
    Beware of advice given by some guy on the Internet.

  3. #3
    Join Date
    Nov 2001
    Location
    east kansas
    Posts
    8,027
    And long harvest could be a dirty evaporator also. There are little orfices in the grid to aid in harvest. If they are scaled you will have a long harvest.

    The grid may look good wet, but when dry you will be able to see the scale.
    Beware of advice given by some guy on the Internet.

  4. #4
    Join Date
    Jun 2006
    Location
    Omaha, Nebraska
    Posts
    861
    Great advice, thanks! If there's someting to clog, it's clogged with calcium I'm sure.

    The drain line was completely clogged with calcium and I cleared it. The dump valve is staying closed until harvest now. They had it unplugged before because the relay had the valve constantly open with the bad board.

    Since the water has been sitting in the pipes so long I'm thinking maybe I just need to flush it more. They have a well water system with 2 large filters and a UV tube, but I don't know the condition of any of it. There was a TON of calcium in the pan before I cleaned it so I'm suspecting the filtration system might not be working well. Does the suction pressure sound correct? I was thinking that a low charge might be the cause of the slow harvest. The compressor discharge line is not even warm a couple minutes into harvest.

  5. #5
    Join Date
    Aug 2007
    Posts
    241
    Quote Originally Posted by man from trane View Post
    I don't work on ice machines often so I'm a bit rusty. Lately I'm doing a lot of them.

    We get abandoned restaurants frequently on the island. The owner gives up, shuts off the breakers and leaves with food still in the coolers, etc.

    Today I worked on a Manitowoc S series (2004 vintage) that hadn't run for at least 6 months. I've never worked on one of these before, most of what we have are Ice-o-matics. The board was burnt, but after replacing it and running a few harvest cycles the ice is still cloudy. I did a quick cleaning and the water runs clear. It's not running low on water toward the end of the freeze cycle, and the pump doesn't seem to be sucking air. I think it might be a tad low on charge. The suction gets down to about 22 psi (404A) at the end of the harvest. Harvest is also slow, about 3 minutes, 80 psi suction.

    The dishwasher told the new owner that it never worked right since they moved the condenser. It's about 20 feet away and the lines are even insulated. There's no cycling control so the fan runs all the time. Not sure what's wrong here.
    Sounds like you have quite a gem on your hands LOL!!

    Of course the lines should be insulated. What is the model # of the unit? Sounds like a CVD (quite cube with condensing unit located outside) and the fans will work constant in freeze but will cycle during harvest. These units have both a fan cycle control and headmaster.....this ensures the headmaster stays in FULL bypass during harvest and that there is enough head pressure to allow the cool gas from the top of the receiver to correctly harvest the ice.

    With 2 fans on the condenser one will be cycling on at 250# and off at 200# and the other will cycle on at 275# and off at 225#......of course it sounds like the fan control has been bypassed for whatever reason.

    80# suction pressure in harvest sounds not too far off, but this depends on which model number you have. 20# suction at the end of harvest is way low.......that is a pressure you would see at the end of freeze if anything.

    Long harvest could be due to lack of the fan/s cycling and the head pressure falling off too low. It could be also due to a dirty scaled or just worn evaporator plate causing the ice to hang up.

    And to close, cloudy ice could be from the dump valve not opening properly or scale clogging up the piping......when you turn the machine on you will hear the dump valve solenoid click, it will dump the water for 45 seconds....check the drain and see if any water is leaving the machine. Cloudy ice is also from bad water or just old filters......a machine that has not run in 6 months has all of these and many more possibilities.

    If I recall your posts that I have read you do market refrigeration? If you do you will figure this ice machine out.

    Call Manitowoc if needed, there tech support is the best.

    Hope this helps.
    "It's not that I'm so smart, I just spend more time with problems." Albert Einstein

  6. #6
    Join Date
    Jun 2006
    Location
    Omaha, Nebraska
    Posts
    861
    ^ Oops, I meant 22 psi at the end of the freeze cycle. The model # is SY0894N. It's a single condenser fan. The coils are badly eroded from the salt since it's a beach restaurant (at which I will be eating for free for a very long time ) but it still works. I did not stare at the wiring but it didn't look like anything had been modified. I'm going back Thursday if Erika heads north like it should. I think I'll take a closer look at the grid and open up the water filters.

    Yes, I do market work, commercial A/C, chillers, mini splits, pretty much anything that cools or freezes. I also used to do DDC in the states but there's not much of that around here. Thermostats are set at either 60 or 90, on or off.

  7. #7
    Join Date
    Jun 2003
    Location
    I'm on the road to Shambala
    Posts
    249
    I had a Manitowoc that the water line was twisted (hose) and the ice was cloudy and it looked like candle wax running down the evap fixed the water line and no more problems
    Scooter

    UA Local 630
    West Palm Beach, Florida
    RSES
    FL. Class A License

    www.enterpriseaire.com

  8. #8
    Join Date
    Nov 2001
    Location
    east kansas
    Posts
    8,027
    If it freezes okay and doesn't defrost you may have a bad harvest pressure regulator valve and/or solenoid. (If the S series uses them) I haven't worked on any S series since I quit my previous employer, the "new" place doesn't have many ice machine accounts.

    You can look at the piping diagram and bypass the harvest pressure regulator with your manifold set. If you can feed enough refrigerant to harvest correctly replace the solenoid and valve.
    Beware of advice given by some guy on the Internet.

  9. #9
    Join Date
    Jun 2006
    Location
    Omaha, Nebraska
    Posts
    861

    Update:

    I went back and asked the owner about the water filters. He said there were no cartridges when he took over so he put new cartridges in. The ice machine had lots of loose calcium granules all over. I finished cleaning the machine, and found the lines before and after the dump valve 75% clogged with calcium buildup. The dump was only a small trickle. Did I mention they use straight well water?

    So now the machine is harvesting well, but the ice is still cloudy. So out of curiosity I check out the filter set up. The filter bypass was open. I'll let it run a day or so and it will probably be fine. The calcium content of that water is just ridiculous for some reason.

    Thanks for the help!!!

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